JP7332960B2 - Polarization control member and light emitting device - Google Patents

Description

The present invention relates to a polarization control member and a light emitting device.

2. Description of the Related Art Conventionally, techniques for synthesizing light emitted from a plurality of light emitting elements have been known. for example,
Patent Literature 1 discloses a light source unit in which light beams from two semiconductor lasers with different polarizations are incident on a polarizing beam splitter (PBS) and combined.

JP 2016-186566

However, in Patent Document 1, one light source unit has two semiconductor lasers with different polarizations, and light emitted from this light source unit is synthesized. is not disclosed.

A synthesizing apparatus according to the present invention includes a plurality of light emitting devices each having one or more first semiconductor laser elements and one or more second semiconductor laser elements, and the first light emitting device among the plurality of light emitting devices. a first polarization control member for changing the polarization direction of light emitted from the first semiconductor laser element of the light emitted from the second semiconductor laser element of the second light emitting device among the plurality of light emitting devices; a second polarization control member that changes the polarization direction; emitted light from the first light emitting device including light from the first semiconductor laser element whose polarization direction is changed by the first polarization control member; and the second polarized light a synthesizing member for synthesizing the emitted light from the second light emitting device including the light from the second semiconductor laser element whose polarization direction is changed by the control member, wherein the plurality of light emitting devices are , respectively, the polarization direction of the emitted light when the light emitted by the first semiconductor laser element is emitted from the light emitting device, and the polarization direction of the emitted light when the light emitted by the second semiconductor laser element is emitted. direction is different.

Further, the light emitting device according to the present invention is a plurality of light emitting devices mounted in a synthesizing device as a projection device, each light emitting device comprising at least one first semiconductor laser element and at least two second semiconductor laser elements. and wherein the first semiconductor laser element emits red light, one of the two second semiconductor laser elements emits blue light, and the other one emits green light. and the polarization direction of the emitted light when the light emitted by the first semiconductor laser element is emitted from the light emitting device, and the emitted light when the light emitted by the second semiconductor laser element is emitted are different from the polarization directions.

According to the synthesizing device of the present invention, it is possible to effectively synthesize light using a plurality of light emitting devices.

Further, the light-emitting device according to the present invention can be suitably used for a synthesizing device as a projection device according to the present invention, and can provide a projection device capable of effectively synthesizing light using a plurality of light-emitting devices.

FIG. 1 is a schematic diagram showing the optical configuration of a projection device according to an embodiment. FIG. 2 is a perspective view of a first polarization control member according to the embodiment; FIG. 3 is a perspective view of a second polarization control member according to the embodiment; FIG. 4 is a schematic diagram for explaining the center, first diameter, and second diameter of light emitted from a single-emitter semiconductor laser device. FIG. 5 is a schematic diagram for explaining the center, first diameter, and second diameter of light emitted from a multi-emitter semiconductor laser device. FIG. 6 is a perspective view of the light emitting device according to the embodiment. FIG. 7 is a cross-sectional view of the light-emitting device along the straight line connecting VII-VII in FIG. FIG. 8 is a perspective view for explaining the internal structure of the light emitting device. FIG. 9 is a top view for explaining the internal structure of the light emitting device.

A mode for carrying out the present invention will be described below with reference to the drawings. However, the embodiments shown below are for embodying the technical idea of the present invention, and do not limit the present invention. Furthermore, in the following description, the same names and symbols indicate the same or homogeneous members, and detailed description thereof will be omitted as appropriate. Note that the sizes and positional relationships of members shown in each drawing may be exaggerated for clarity of explanation.

In the embodiments, details of the invention will be described by citing a projection device 1 as an example of a synthesizing device. The synthesis device has a plurality of light emitting devices 100, a first polarization control member 21, a second polarization control member 22, and a synthesis member. Each of the plurality of light emitting devices 100 has one or more first semiconductor laser elements 121 and one or more second semiconductor laser elements 122 .

FIG. 1 is a diagram showing the optical configuration of a projection device 1 according to an embodiment. Also, the arrows are supplementarily added to explain the traveling direction of the light. The projection device 1 is a device that projects images such as moving images and still images onto a screen. A projector is an example of the projection device 1 .

The projection apparatus 1 includes two light emitting units 10, two polarization control members 20, a mirror 30, a polarization beam splitter (hereinafter referred to as PBS) 40, four lenses 50, and a digital micromirror device (hereinafter referred to as DMD) 60. , the two prisms 70 and the projection unit 8
have 0. Note that the configuration is not limited to two as long as the number of light emitting units 10 and polarization control members 20 is plural. Lenses 50 are not limited to a configuration of four. Prism 70 is not limited to two configurations.

Also, the light emitting unit 10 has a light emitting device 100 and a mounting board 103 . The two polarization control members 20 are a first polarization control member 21 and a second polarization control member 22 . 4
The three lenses 50 are a diffusing lens 51 , a collimating lens 52 , a lens array 53 and a superimposing lens 54 .

Here, in this specification, when distinguishing between the two light emitting units 10, they are referred to as the first light emitting unit 11 and the second light emitting unit 12, respectively. Also, the first light emitting unit 11
and the light emitting device 100 of the second light emitting unit 12 are referred to as a first light emitting device 101 and a second light emitting device 102, respectively.

The light emitting device 100 also has a plurality of semiconductor laser elements 120 . This semiconductor laser element 120 emits linearly polarized light. Also, the plurality of semiconductor laser elements 120 includes one or more first semiconductor laser elements 121 and one or more second semiconductor laser elements 122 .

The first semiconductor laser element 121 and the second semiconductor laser element 122 have different polarization directions of light emitted from the light emitting device 100 . Also, the first semiconductor laser element 121 and the second
Light emitted from each of the semiconductor laser elements 122 is emitted from the light emitting device 100 in the same direction.

That is, the emitted light from the first semiconductor laser element 121 and the emitted light from the second semiconductor laser element 122, which are emitted in the same direction from the light emitting device 100, have different polarization directions. Here, the light emitted from the semiconductor laser element 120 until it is emitted to the outside of the light emitting device 100 is called emitted light, and the light after being emitted to the outside of the light emitting device 100 is called emitted light.

For example, the light-emitting device 100 can use the first semiconductor laser element 121 and the second semiconductor laser element 122 in which the polarization directions of the light emitted from the emitting facet are different. As such a semiconductor laser element 120, for example, the first semiconductor laser element 121 is a semiconductor laser element 120 whose polarization is TM mode (TM polarization), and the second semiconductor laser element 122 is a semiconductor laser element 120 whose polarization is TE.
The semiconductor laser element 120 can be a mode (TE polarization). An example of the light emitting device 100 applied to the projection device 1 will be described later.

Here, the emitted light from the semiconductor laser element 120 has a length in the stacking direction of the plurality of semiconductor layers including the active layer, which is larger than the length in the direction perpendicular to the plane parallel to the light emitting end face of the semiconductor laser element 120 . has a long, elliptical far-field pattern (FFP). FF
P is the shape and light intensity distribution of emitted light at a position sufficiently distant from the light emitting end face of the semiconductor laser element 120 .

In this specification, the light having the light intensity of 1/e ² or more of the peak intensity value is referred to as the light of the main portion of the semiconductor laser device 120 . In addition, when we say FFP, we mean the shape of FFP by light with light intensity of 1/e ² of the peak intensity value. Also, the light traveling through the center of the ellipse representing the FFP is called central light. A straight line passing through the center of the ellipse of the FFP and the radiation position of the central light on the output end face is defined as the optical axis. In other words, in this specification, the central light is the light passing through the optical axis from the output end face.

In the light emitting device 100, the first semiconductor laser element 121 and the second semiconductor laser element 122
means that at least each central light is emitted in the same direction. Here, "same direction" includes a difference of 5 degrees. Alternatively, the design of the light-emitting device 100 is designed to proceed in the same direction, and includes a range of error that occurs during manufacturing.

One light emitting device 100 can have one or a plurality of first semiconductor laser elements 121 and second semiconductor laser elements 122, respectively. Further, the light emitting device 100 may further include another semiconductor laser element 120 in which the polarization direction of the central light emitted from the light emitting device 100 is different from both the first semiconductor laser element 121 and the second semiconductor laser element 122 .

In the example shown in FIG. 1, in one light emitting device 100, light emitted from three semiconductor laser elements 120 is emitted. Moreover, each emitted light is collimated and emitted as collimated light. Here, one of the three semiconductor laser elements 120 is the first semiconductor laser element 121 and two are the second semiconductor laser elements 122 .

With respect to the emitted light emitted from the first light emitting device 101 and the emitted light emitted from the second light emitting device 102, the emitted light from the respective first semiconductor laser elements 121 travels in the same traveling direction (emission direction) and in the same direction. Emitted in the polarization direction. Similarly, each second semiconductor laser element 12
2 are also emitted in the same direction and in the same polarization direction. Here, the same polarization direction means that the relative angle difference between the polarization directions of the emitted light from the semiconductor laser elements 120 is within 10 degrees.

In the example shown in FIG. 1, the two light emitting units 10 are arranged side by side in the same direction. Between the two light emitting units 10, the traveling direction of the central light and the first semiconductor laser element 1
21 and the polarization directions of the second semiconductor laser elements 122 are arranged to be the same.

The polarization control member 20 has a dichroic mirror 200 and a wavelength plate 201 . 2 and 3 are perspective views schematically showing the first polarization control member 21 and the second polarization control member 22, respectively. The first polarization control member 21 is a member that controls the polarization direction of light emitted from the first light emitting device 101 of the first light emitting unit 11 . The second polarization control member 22 is the second light emitting unit 12
It is a member for controlling the polarization direction of the emitted light from the second light emitting device 102 .

Each of the first polarization control member 21 and the second polarization control member 22 has three dichroic mirrors 200 arranged side by side. Each of the three dichroic mirrors 200 corresponds to each of the three semiconductor laser elements 120 arranged in the light emitting device 100 . That is, based on the wavelength of light emitted by the corresponding semiconductor laser element 120, the dichroic mirror 200 reflects light of that wavelength, but transmits light of other wavelengths.

Note that the number of dichroic mirrors 200 is not limited to three as long as it is plural. Also, the number does not have to match the number of semiconductor laser elements 120 arranged in the light emitting device 100 . Also, 1
As for the dichroic mirror 200, which only needs to reflect the light emitted from one semiconductor laser element 120 and not transmit the light emitted from another semiconductor laser element 120, a mirror that only reflects is used in place of the dichroic mirror 200. may be used.

The three dichroic mirrors 200 synthesize the emitted light from the three semiconductor laser elements 120 . That is, by passing through the three dichroic mirrors 200, the emitted light from the three semiconductor laser elements 120 travels in the same direction. Note that the same direction means that the relative angle difference between the directions in which the central light travels between arbitrary two semiconductor laser devices 120 out of the three semiconductor laser devices 120 is within 5 degrees. .

Here, using FIGS. 4 and 5, the center, first diameter, and second diameter of the light emitted from each semiconductor laser element 120 are defined. 4 shows the case of a single-emitter semiconductor laser device 120 with one emitter (light-emitting point), and FIG. 5 shows the case of a multi-emitter semiconductor laser device 120 with two emitters. In each figure, the oval shape represents the FFP. A point P indicates the center, a line segment X indicates the first diameter, and a line segment Y indicates the second diameter. It should be noted that the semiconductor laser device 120 is shown partially near the emission point.

As shown in FIG. 4, in the single-emitter semiconductor laser element 120, one elliptical shape corresponding to one emitter is marked. On the other hand, in the multi-emitter semiconductor laser element 120, a plurality of elliptical shapes corresponding to a plurality of emitters are drawn. In FIG. 5, two laser beams are emitted from each light emitting point and two FFPs are marked.

As shown in FIG. 4, in the case of a single emitter, the point passing through the optical axis is the center and FF
The major axis of P is the first diameter, and the minor axis is the second diameter. That is, in this specification, the first diameter is FF
The second diameter is the diameter in the direction corresponding to the major axis of P, and the second diameter is the diameter in the direction corresponding to the minor axis of FFP.

Next, when the emitters are two multi-emitters, the center is the center of gravity of two points with the same optical path length for light passing through the optical axes of the two FFPs, in this case the midpoint between the two points.
In the smallest rectangle that includes both elliptical shapes, the length of the side corresponding to the major axis direction of the ellipse is the first diameter, and the length of the side corresponding to the minor axis direction of the ellipse is the second diameter. . Here, "corresponding" preferably means that the directions of the sides of the rectangle and the radius of the ellipse are the same. of the combinations of sides and diameters with a small relative angular difference.

For a multi-emitter having three or more emitters, the center, the first diameter, and the second diameter can be defined in the same way. That is, the center is the center of gravity obtained based on the points passing through the optical axes of all emitters when the optical path length is the same, and the first diameter and the second diameter are the smallest rectangles that include all FFPs. It is the length of the side corresponding to the major axis direction or the minor axis direction obtained based on the above.

Let P be the center defined in this way, X be the first diameter, and Y be the second diameter. For the first semiconductor laser element 121, which is the first semiconductor laser element 120, P(1), X(1), Y
(1), P(2), X(2), and Y(2) for the second semiconductor laser element 122, which is the second semiconductor laser element 120, and for the third semiconductor laser element 120, The other second semiconductor laser element 122 is represented by P(3), X(3), and Y(3). Note that even when the light emitting device 100 has four or more semiconductor laser elements 120,
Based on the same concept, numbers are given in parentheses for distinction.

The light emitted from the three semiconductor laser elements 120 has the sum of the first diameters of the light from the three semiconductor laser elements 120 on one side at the point of emission from the polarization control member 20. It is preferable to combine them so as to fit in a rectangle whose other side length is the sum of the second diameters of the three semiconductor laser elements 120 . That is, P(1), P
(2) and P(3) have X(1)+X(2)+X(3) as one side and Y(1)+Y(
2) It is preferable that they are gathered within a rectangular area having +Y(3) as the other side.

Furthermore, the sum of the first diameters of the three semiconductor laser elements 120 is the sum of the first diameters of the three semiconductor laser elements 120 at the point where the light emitted from the three semiconductor laser elements 120 is emitted from the polarization control member 20. of each of the three semiconductor laser elements 120 and the second
It is preferable to synthesize them so as to fit within a rectangle having the length of the other side equal to the sum of the diameters.

Moreover, it is desirable that each member be mounted based on a design such that the centers of the lights emitted from the three semiconductor laser elements 120 are overlapped and synthesized by the polarization control member 20 . By synthesizing the light in this way, it is possible to synthesize the main portion of the light emitted from the three semiconductor laser elements 120 so as to be contained in a smaller area. Even if the light-emitting device 100 has four or more semiconductor laser elements 120, the sum of the diameters of the semiconductor laser elements 120 or the center thereof may be used.

The wave plate 201 included in the first polarization control member 21 is the first wavelength plate arranged in the first light emitting device 101 .
The polarization direction of the emitted light from the semiconductor laser element 121 is changed. Also, the second polarization control member 22
The wavelength plate 201 of the second semiconductor laser element 122 arranged in the second light emitting device 102
change the polarization direction of the emitted light. As the wave plate 201, for example, a λ/2 wave plate that gives a phase difference of λ/2 can be used. The λ/2 wave plate rotates the polarization direction by 90 degrees.

In the example shown in FIG. 1, one first semiconductor laser element 121 and two second semiconductor laser elements 122 are arranged in the light emitting device 100 . Therefore, the first polarization control member 21 has one wavelength plate 201 corresponding to one first semiconductor laser element 121, and the second polarization control member 22 corresponds to each of the two second semiconductor laser elements 122. two wave plates 2
01.

The wave plate 201 is arranged so that the light emitted from the light emitting device 100 enters the wave plate 201 before entering the dichroic mirror 200 . In the example shown in FIG. 1, a wavelength plate 20 is provided on a surface (incidence surface) of the dichroic mirror 200 on which light emitted from the light emitting device 100 is incident.
1 are joined together to form a polarization control member 20 . In this way, by forming the polarization control member 20 in which the dichroic mirror 200 and the wavelength plate 201 are integrally bonded, the synthesizing device can be designed to be more compact.

It should be noted that the polarization control member 20 may not be the one in which the dichroic mirror 200 and the wavelength plate 201 are integrally bonded. For example, the dichroic mirror 200 and the wavelength plate 201 may be provided separately. In this case, the wave plate 201 that changes the polarization direction of light is the polarization control member 2 .
Equivalent to 0.

The wave plate 201 of the first polarization control member 21 rotates the polarization direction of the light emitted from the first semiconductor laser element 121 by 90 degrees, making it the same as the polarization direction of the light emitted from the second semiconductor laser element 122 . Further, the polarization direction of the emitted light from the second semiconductor laser element 122 is rotated 90 degrees by the wavelength plate 201 of the second polarization control member 22, and becomes the same as the polarization direction of the emitted light from the first semiconductor laser element 121. . Therefore, in the emitted light before entering the polarization control member 20, the emitted light from the first semiconductor laser element 121 and the emitted light from the second semiconductor laser element 122 emitted from the light emitting device 100 have a polarization direction of 90°. degrees are different.

The mirror 30 is a light reflecting member that reflects light incident on its reflecting surface. In the projection device 1 , the mirror 30 is provided for the emitted light from the second light emitting device 102 . Moreover, it is not provided for the light emitted from the first light emitting device 101 . Note that the light emitted from the first light emitting device 101 may be provided, and the light emitted from the second light emitting device 102 may not be provided. Also, a plurality of mirrors 30 may be provided corresponding to each of the first light emitting device 101 and the second light emitting device 102 .

The PBS 40 is an optical filter that transmits p-polarized light and reflects s-polarized light. In the projection device 1 , the light emitted by the first and second semiconductor laser elements 122 of the first light emitting device 101 is aligned into p-polarized light by the first polarization control member 21 and enters the PBS 40 . Also,
The light emitted by the first and second semiconductor laser elements 122 of the second light emitting device 102 is aligned into s-polarized light by the second polarization control member 22 and enters the PBS 40 .

As a result, the PBS 40 transmits light emitted from the first light emitting device 101 and reflects light emitted from the second light emitting device 102 . As a result, the emitted light from the first light emitting device 101,
The emitted light from the second light emitting device 102 is synthesized. That is, the PBS 40 causes the emitted light from the first light emitting device 101 and the emitted light from the second light emitting device 102 to travel in the same direction.

It should be noted that the same direction here means that between the lights from any two semiconductor laser elements 120 among the six semiconductor laser elements 120 mounted on the first light emitting device 101 and the second light emitting device 102. It means that the relative angular difference in the traveling direction of the center light is within 10 degrees. The PBS 40 is an example of a synthesizing member that synthesizes the light emitted from the first light emitting device 101 and the light emitted from the second light emitting device 102 .

The light emitted from the first light emitting device 101 to be synthesized includes the light from the first semiconductor laser element 121 whose polarization direction is changed by the first polarization control member 21 and the light from the second semiconductor laser element 122 . are doing. The light emitted from the second light emitting device 102 to be synthesized is the light from the first semiconductor laser element 121 and the light from the second semiconductor laser element 122 whose polarization direction is changed by the second polarization control member 22 . have.

The light emitted from the six semiconductor laser elements 120 has the sum of the first diameters of the six semiconductor laser elements 120 as the length of one side at any center at the point of emission from the PBS 40, and the six semiconductor laser elements 120 It is preferable that the laser elements 120 be synthesized so as to fit in a rectangle having the length of the other side equal to the sum of the second diameters of the laser elements 120 .

That is, P(1), P(2), P(3), P(4), P(5), and P(6) are X
(1) + X (2) + X (3) + X (4) + X (5) + X (6) as one side, Y (1) + Y
It is preferable that they are gathered in a rectangular area having (2)+Y(3)+Y(4)+Y(5)+Y(6) as the other side.

Furthermore, the sum of the first diameters of the lights of the six semiconductor laser elements 120 is the sum of the first diameters of the lights of the six semiconductor laser elements 120 at the point of emission from the PBS 40. It is preferable to synthesize the light beams so as to fit within a rectangle whose other side length is the sum of the second diameters of the light beams from the six semiconductor laser elements 120 .

Moreover, the first light emitting device 101 and the second light emitting device 102 are mounted based on a design in which the centers of light from the semiconductor laser elements 120 having the same arrangement relationship are overlapped and synthesized by the PBS 40. is desirable. The semiconductor laser elements 120 having the same arrangement relationship are the first semiconductor laser elements 121, the second semiconductor laser elements 122 adjacent to the first semiconductor laser elements 121, and the remaining semiconductor laser elements 122 adjacent to the first semiconductor laser elements 121. of the second semiconductor laser elements 122 correspond to each other. By synthesizing light in this way, six semiconductor laser elements 1
The main portion of light emitted from 20 can be combined to fit into a smaller area.

The light emitted from the first light-emitting device 101 and the second light-emitting device 102 is combined by the PBS 40 to obtain 140 of the light energy of the emitted light at the point emitted from the first light-emitting device 101 or the second light-emitting device 102. % or more of the light is emitted from the PBS 40 .
Alternatively, the light energy of the emitted light at the point emitted from the first light emitting device 101 and the second
70% or more of the sum of the light energy of the light emitted from the light emitting device 102 and the light energy emitted from the point emitted from the light emitting device 102 is emitted from the PBS 40 . The light energy can be measured by, for example, a power meter, and the unit is, for example, watts.

Here, the arrangement of each component up to the synthesis of light by the PBS 40 in the embodiment will be described. Of the two light emitting units 10, the first light emitting unit 11 is arranged farther from the PBS 40 than the second light emitting unit 12 is. Also, the first light emitting unit 11
and the first polarization control member 21 is longer than the distance between the second light emitting unit 12 and the second polarization control member 22 . Also, the emitted light reflected by the dichroic mirror 200 of the first polarization control member 21 and the emitted light reflected by the dichroic mirror 200 of the second polarization control member 22 travel in the same direction.

The emitted light reflected by the dichroic mirror 200 of the second polarization control member 22 is reflected by the mirror 30, and is 90 degrees different from the direction in which the emitted light reflected by the dichroic mirror 200 of the first polarization control member 21 travels. move on. Then, when incident on the PBS 40, the traveling direction of the emitted light from the first light emitting device 101 and the traveling direction of the emitted light from the second light emitting device 102 differ by 90 degrees.

In this way, in order to use the transmissive and reflective properties of the PBS 40 by varying the direction of incidence on the PBS 40 by 90 degrees, in the first light emitting device 101, the polarization direction of the first semiconductor laser element 121 is changed and the second semiconductor laser element 121 is polarized. The polarization direction of the second semiconductor laser element 122 is changed to match the polarization direction of the first semiconductor laser element 121 in the second light emitting device 102 .

The diffuser lens 51 diffuses the light synthesized in this way (hereinafter referred to as synthesized light). The diffuser lens 51 has the shape of a concave lens with a cylindrical surface. By forming a cylindrical surface, it is possible to prevent light from being diffused by the diffuser lens 51 in a direction having no curvature.

In the projection device 1, the diffuser lens 51 is arranged so that, of the light from the semiconductor laser element 120 having an elliptical FFP, the major axis direction of the ellipse is the direction in which the cylindrical surface has no curvature. The irradiation area of the combined light when entering the diffuser lens 51 has a width in the direction corresponding to the light passing through the major axis of the ellipse greater than the width in the direction corresponding to the light passing through the minor axis of the ellipse. Therefore, passing through the diffuser lens 51 reduces the difference in width.

The light that has passed through the diffusion lens 51 passes through the collimator lens 52, so that the light in the direction of diffusion, that is, the light in the direction corresponding to the minor axis of the ellipse is collimated. Note that the direction corresponding to the major axis of the ellipse has already been collimated. Light collimated by the collimating lens 52 is split into a plurality of small light beams by passing through the lens array 53 . The light split into a plurality of small bundles of light by the lens array 53 passes through the superimposing lens 54 and is superimposed so that more uniform light is incident on the DMD 60 . The DMD 60 time-divisionally modulates the incident light to generate image light to be projected on the screen. Image light generated by the DMD 60 passes through two prisms 70 and enters the projection unit 80 . The image light incident on the projection unit 80 is projected onto the screen.

As described above, according to the projection device 1, by using a plurality of light emitting devices 100 that emit light with different polarization directions, the light emitted from the plurality of light emitting devices 100 can be effectively combined.

Next, with reference to FIGS. 6 to 9, the light emitting device 100 applied to the projection device 1 according to the embodiment.
Describes one form of Note that the form of the light emitting device 100 applied in the projection device 1 is not limited to this. FIG. 6 is a perspective view of the light emitting device 100 bonded to the mounting substrate 103. FIG. Figure 7
7 is a cross-sectional view taken along a straight line connecting VII-VII in FIG. 6; FIG. FIG. 8 is a perspective view for explaining the internal structure of the light emitting device 100. FIG. FIG. 9 is a top view for explaining the internal structure of the light emitting device 100. FIG.

The light emitting device 100 includes, as components, a base 110, three semiconductor laser elements 120, a submount 130, a light reflecting member 140, a protective element 160, a wire 150, a lid member 170,
It has an adhesive portion 180 and a lens member 190 . Among the three semiconductor laser elements 120 , one is the first semiconductor laser element 121 and two are the second semiconductor laser elements 122 .

The base 110 has a bottom surface BS and an outer surface OS that intersects with the bottom surface BS. In addition, it has a first upper surface UA, an inner surface IS that intersects with the first upper surface UA, and a second upper surface UB that intersects with the inner surface IS on the side opposite to the first upper surface UA, and the outer surface OS and the inner surface IS. It intersects with the second upper surface UB on the opposite side. Moreover, a step is formed on a part of the inner surface IS. Therefore, in the portion where the step is formed, the inner side surface IS has a first inner side surface IA that intersects with the first upper surface UA and a second inner surface IA that intersects with the second upper surface UB.
and an inner surface IB. A third upper surface UC is formed to intersect the first inner side surface IA and the second inner side surface IB. The base 110 also forms a concave structure, the depression of which extends from the second upper surface UB to the first upper surface UA. Therefore, when viewed from above, the first upper surface UA is the second upper surface UB
surrounded by

The base 110 can be formed using ceramic as a main material. In addition, you may form not only with a ceramic but with a metal. For ceramics, for example, aluminum nitride, silicon nitride,
The main material of the base 110 can be aluminum oxide or silicon carbide, copper, aluminum or iron as a metal, or copper molybdenum, a copper-diamond composite material or copper tungsten as a composite.

A plurality of metal films 111 are provided on the third upper surface UC of the base 110 . A metal film 111 is also provided on the lower surface. The metal film 111 on the third upper surface UC and the metal film 111 on the lower surface can be electrically connected by the metal passing through the inside of the base portion 110 .

Note that the base 110 may be formed by using different main materials for the frame forming the frame and the bottom forming the first upper surface, and joining the frame and the bottom. for example,
A plate-shaped bottom part made mainly of metal and having a thickness from the first upper surface UA to the lower surface BS is joined to a frame part made mainly of ceramic and having a frame having a height from the second upper surface UB to the lower surface BS. may be formed by

The first semiconductor laser element 121 has a lower surface, an upper surface, and side surfaces, and emits TM-mode laser light from one side surface. The two second semiconductor laser elements 122 each have a lower surface, an upper surface, and side surfaces, and radiate laser light polarized in TE mode from one side surface.

Also, the first semiconductor laser element 121 emits red light. Of the two second semiconductor laser elements 122, one emits blue light and the other emits green light. Note that semiconductor laser elements 120 that emit light of other colors may be used, and a plurality of semiconductor laser elements 120 of the same color may be arranged. Also, the number of arranged semiconductor laser elements 120 need not be limited to three as long as it is one or more.

Here, red light means light whose emission peak wavelength is in the range of 605 nm to 750 nm. As red light employed in the light emitting device 100, 610 nm to 700 nm
Those in the range of m are even more preferred. Examples of the semiconductor laser element 120 that emits red light include those containing InAlGaP-based, GaInP-based, GaAs-based, and AlGaAs-based semiconductors. The output power of these semiconductor laser elements 120 is more likely to decrease due to heat than the semiconductor laser elements 120 containing a nitride semiconductor. Considering this point, it is preferable to provide two or more waveguide regions. By increasing the waveguide region, heat can be dispersed, and the reduction in the output of the semiconductor laser element 120 can be reduced.

Blue light refers to light whose emission peak wavelength is in the range of 420 nm to 494 nm. Blue light used in the light emitting device 100 is preferably in the range of 440 nm to 475 nm. As the semiconductor laser element 120 that emits blue light, there is a semiconductor laser element 120 containing a nitride semiconductor. Examples of nitride semiconductors include
GaN, InGaN, and AlGaN can be used.

Green light refers to light whose emission peak wavelength is in the range of 495 nm to 570 nm. Green light used in the light emitting device 100 is more preferably in the range of 510 nm to 550 nm. As the semiconductor laser element 120 that emits green light, there is a semiconductor laser element 120 containing a nitride semiconductor. Examples of nitride semiconductors include
GaN, InGaN, and AlGaN can be used.

The first semiconductor laser element 121 is a multi-emitter semiconductor laser element 120 having two emitters as shown in FIG. The second semiconductor laser element 122 is shown in FIG.
1 is a single-emitter semiconductor laser device 120 as shown in FIG.

The submount 130 has a bottom surface, a top surface, and side surfaces and is configured in the shape of a rectangular parallelepiped. Note that the shape is not limited to a rectangular parallelepiped. Submount 130 may be formed using, for example, silicon nitride, aluminum nitride, or silicon carbide. Moreover, other materials can also be used without being limited to this. A metal film is provided on the upper surface of the submount 130 .

The light reflecting member 140 has a lower surface, a side surface that intersects with the lower surface, and an upper surface that intersects a part of the side surface on the opposite side of the lower surface. In addition, it has a light reflecting surface that intersects with another partial side surface on the side opposite to the lower surface and intersects with the side surface of the upper surface in a region that does not intersect. The light reflecting surface is flat and slopes from the upper surface to the lower surface. The light reflecting surface is designed to form an angle of 45 degrees with respect to the lower surface. Note that this angle is not limited to 45 degrees, and the light reflecting surface may be a curved surface instead of a flat surface.

The light reflecting member 140 can be formed by forming an outer shape using a main material, and forming a light reflecting film on a surface of the formed outer shape on which a light reflecting surface is desired. The main material is preferably a heat-resistant material such as quartz or glass such as BK7 (borosilicate glass), metal such as aluminum, or Si. The light reflection film is preferably made of a material with high light reflectance, and employs metals such as Ag and Al, dielectric multilayer films such as Ta ₂ O ₅ /SiO ₂ , TiO ₂ /SiO ₂ , Nb ₂ O ₅ /SiO _2, etc. can do.

In addition, when the outer shape is formed using a material having a high light reflectance such as metal as the main material, the formation of the light reflecting film may be omitted. The light reflecting surface can have a light reflectance of 99% or more with respect to the peak wavelength of the laser light to be reflected. These light reflectances are 100% or less or 100%
%. Protective element 160 is, for example, a Zener diode. The wire 150 is metal wiring.

The lid member 170 has a lower surface, an upper surface, and side surfaces, is configured in the shape of a rectangular parallelepiped, and is translucent as a whole. Note that a part may have a non-light-transmitting region. Also, the shape is not limited to a rectangular parallelepiped. The lid member 170 can be formed using sapphire as a main material.
Also, a metal film is provided in a part of the region. Sapphire is a material with a relatively high refractive index and relatively high strength. In addition to sapphire, for example, glass or the like can also be used as the main material.

The adhesive portion 180 is formed by hardening the adhesive. As the adhesive that forms the adhesive portion 180, an ultraviolet curable resin can be used. Since the ultraviolet curable resin can be cured in a relatively short time without heating, it is easy to fix the lens member 190 at a desired position.

The lens member 190 has a bottom surface, side surfaces, and a top surface that intersects the side surfaces. Further, the upper surface of the lens member 190 includes a lens portion 191 having a lens shape and a non-lens portion 19 other than the lens portion 191 .
2 and Alternatively, the lens member 190 has a shape in which a lens-shaped lens portion 191 is arranged on the upper surface of a rectangular parallelepiped non-lens portion 192 . A plurality of lens portions 191 are provided on the upper surface of the lens member 190 . The plurality of lens portions 191 are molded in a shape that is integrally connected. Glass such as BK7 and B270 can be used for the lens member 190, for example.

The mounting board 103 has a bottom surface, a side surface, and a top surface. The main material is metal, and the insulating film 123 and the metal film 113 are provided thereon. The upper surface of the mounting substrate 103 has areas where the insulating film 123 and the metal film 113 are exposed. Examples of metals include
Aluminum or copper can be used. By using such a metal, a good heat radiation effect can be obtained for heat generated from the first semiconductor laser element 121 and the second semiconductor laser element 122 . That is, the mounting substrate 103 can also serve as a heat dissipation member.

Next, the light-emitting device 100 manufactured using these components will be described.
Three semiconductor laser elements 120 are arranged on the first upper surface UA of the base 110 via a submount 130 . Also, the submount 130 is separately provided for each semiconductor laser element 120 . A plurality of semiconductor laser elements 120 may be arranged on the top surface of one submount 130 . Also, the semiconductor laser element 120 may be arranged directly on the first upper surface UA without the submount 130 interposed therebetween.

The submount 130 has its lower surface bonded to the first upper surface UA of the base 110 and its upper surface bonded to the semiconductor laser element 120 . The semiconductor laser element 120 is arranged so that the emission end face of the semiconductor laser element 120 is aligned with the side surface of the submount 130 or protrudes. This prevents the light emitted from the semiconductor laser element 120 from irradiating the upper surface of the submount 130 . Also, a protective element 160 is arranged on the upper surface of the submount 130 .

If the submount 130 has a higher thermal conductivity than the first upper surface UA of the base 110, a higher effect as a heat spreader can be obtained. For example, base 11
If aluminum nitride is used for the first upper surface UA of 0, the submount 130 can be aluminum nitride or silicon carbide. Note that submount 1 in this case
The aluminum nitride used for 30 has a higher thermal conductivity than the aluminum nitride used for base 110 .

Also, the submount 130 is designed so that the three semiconductor laser elements 120 have the same height from the first upper surface UA. In addition, the emission end face of each semiconductor laser element 120 is designed to be arranged on the same virtual plane. Even if the design is the same, errors occur due to component tolerances and mounting tolerances in the mounting stage. Regarding the light emitting device 100,
When the height, length, position, relative positional relationship, etc. are the same, such errors shall include a tolerance range.

The light reflecting member 140 is arranged on the first upper surface UA of the base 110 . A separate light reflecting member 140 is arranged corresponding to each semiconductor laser element 120 . In addition, between the three semiconductor laser elements 120, the light reflecting member 14 corresponding to the emission end face of each semiconductor laser element 120
The distance between 0 is designed to be the same. In addition, in all three semiconductor laser elements 120, the central light reflected by the light reflecting member 140 travels in a direction perpendicular to the first upper surface UA. One light reflection member 14 corresponding to a plurality of semiconductor laser elements 120
0 may be assigned.

A major part of the light emitted from the semiconductor laser element 120 is applied to the corresponding light reflecting surface of the light reflecting member 140 . By using the light reflecting member 140, the optical path length of the light emitted from the semiconductor laser element 120 can be made longer than when the light reflecting member 140 is not interposed. The longer the optical path length, the smaller the influence of mounting misalignment between the light reflecting member 140 and the semiconductor laser element 120 .

One end of a plurality of wires 150 is joined to the metal film 111 provided on the upper surface (third upper surface UC) of the stepped portion. The other ends of the plurality of wires 150 are joined to the metal film provided on the upper surface of the semiconductor laser element 120, the protective element 160, or the submount 130, respectively. As a result, the semiconductor laser element 120 and the protection element 160 are separated from each other by the metal film 11 provided on the lower surface of the base 110.
1 are electrically connected.

A stepped portion is not provided on the inner surface IS of the base portion 110 ahead of the traveling direction of the light emitted from the semiconductor laser element 120 and passing through the optical axis. A stepped portion is provided on the inner surface IS, and the wire 150
When the wire 150 is stretched, the wire 150 straddles the light reflecting member 140 and becomes an obstacle on the optical path of the reflected light. The size of the base portion 110 can be reduced by not providing the step portion over the entire circumference of the inner surface.

The lid member 170 is joined to the second upper surface UB of the base 110 at its lower surface. Lid member 1
70 and base 110 are provided with a metal film in the region to be joined, and are fixed via Au—Sn or the like. A closed space is formed by joining the base portion 110 and the lid member 170 . This closed space becomes a hermetically sealed space. Such hermetic sealing can prevent organic matter and the like from collecting on the light emitting facet of the semiconductor laser element 120 .

Reflected light reflected by the light reflecting surface of the light reflecting member 140 enters the lid member 170 . The lid member 170 is designed so that at least a main portion of the reflected light is translucent in the region from the incidence to the emission. Here, translucency means that the transmittance to light is 80% or more.

The bonding portion 180 is formed in a region where the lid member 170 and the lens member 190 are bonded together on the upper surface of the lid member 170 . The adhesive part 180 is formed by curing the adhesive in a state where the adhesive is attached to the upper surface of the lid member 170 and the lower surface of the lens member 190 . At this time, the adhesive portion 1
80 is formed so that the lid member 170 and the lens member 190 do not come into contact with each other. By making the bonding portion 180 thicker in this way, the lens member 190 can be bonded to the lid member 170 after adjusting the position and height. Also, the bonding portion 180 is formed so as not to be provided on the optical path of the light emitted from the semiconductor laser element 120 . Therefore, it is preferably formed on the outer edge of the lens member 190 .

The lens member 190 is joined to the lid member 170 via the bonding portion 180 and arranged on the lid member 170 . The number of lens portions 191 in lens member 190 is the same as the number of semiconductor laser elements 120 arranged on base portion 110 . Accordingly, when three semiconductor laser elements 120 are arranged, the lens member 190 is provided with three lens portions 191 integrally connected.

Also, one semiconductor laser element 120 corresponds to one lens portion 191 . Each lens portion 191 is arranged and arranged so that the reflected light reflected by the light reflection member 140 out of the main part of the light emitted from the corresponding semiconductor laser element 120 passes through the lens portion 191 and is collimated. shape is designed.

In the light-emitting device 100 , the pair of metal films 111 provided on the lower surface is aligned with the metal film 1 of the mounting substrate 103 .
13. The light emitting device 100 and the mounting substrate 103 can be joined together by soldering. Bonding of the metal film 111 on the lower surface of the light emitting device 100 and the metal film 113 of the mounting substrate 103 allows self-alignment when fixing the light emitting device 100 to the mounting substrate 103 .

Such a light emitting device 100 emits red, blue, and green collimated lights to the outside of the light emitting device 100 . Also, these collimated lights travel in a direction perpendicular to the upper surface of the mounting substrate 103 or the first upper surface UA of the base 110 . In addition, since the central light of the three semiconductor laser elements 120 travels in the same direction from the emission end face, the first semiconductor laser element 12 is radiated from the emission end face and passes through the lens member 190 .
1 and the light emitted from the second semiconductor laser element 122 have different polarization directions by 90 degrees. For example, if one is p-polarized, the other is s-polarized.

Further, the light emitting device 100 is bonded to the mounting substrate 103 and incorporated into the projection device 1 as the light emitting unit 10. At this time, the first semiconductor laser device 121 of the three semiconductor laser devices 120 has an optical path length up to the PBS 40. is arranged to be the shortest. From another point of view, the multi-emitter first semiconductor laser element 121 is the single-emitter second semiconductor laser element 121 .
It is arranged so that the optical path length to the PBS 40 is shorter than that of the semiconductor laser element 122 .

In the case of multi-emitters, laser light is emitted from each emitter. Central light from each emitter passes through different points of one lens portion 191 . After passing through the lens portion 191, the central lights approach each other and intersect at a certain point. After crossing like that, they move away from each other. In other words, the light emitted from the multi-emitter first semiconductor laser element 121 has a longer distance between the central lights after the crossing as the optical path length increases. Therefore, by arranging the first semiconductor laser element 121 so that the optical path length to the PBS 40 is shorter than that of the second semiconductor laser element 122, the spread can be suppressed.

Although one embodiment to which the present invention is applied has been disclosed above, the present invention can be applied without being limited to this embodiment. For example, by using part or all of the optical configuration shown in the projection device 1 according to the embodiment, it is possible to construct a synthesizing device that synthesizes the light emitted from each of the plurality of light emitting units. The synthesizing device is composed of a plurality of light emitting units and a synthesizing unit for synthesizing light emitted from the plurality of light emitting devices.

Also, the light emitting unit has at least a light emitting device, and the synthesizing unit has at least a polarization control member and a synthesizing member. Also, the synthesizing unit includes the dichroic mirror 200, wave plate 201, mirror 30, PBS 40,
It can consist of part or all of lens 50, DMD 60, prism 70 and projection unit 80. FIG. Therefore, the synthesizing device can be applied not only to the synthesizing device as the projection device 1 but also to various devices for controlling light.

Also, the projection apparatus having technical features is not limited to the structure of the projection apparatus 1 disclosed in the embodiment. For example, the present invention can be applied even to a projection apparatus having components not disclosed in the embodiments, and the difference from the projection apparatus 1 of the embodiment is the basis for not being able to apply the present invention. not.

This means that the present invention can be applied without necessarily having all the components of the projection device 1 disclosed by the embodiment. For example, if some of the constituent elements of the projection apparatus 1 disclosed in the embodiments are not described in the claims, some of the constituent elements may be replaced, omitted, modified in shape, or changed in material. It is claimed that the freedom of design such as modification by a person skilled in the art is allowed, and that the invention described in the scope of claims is applied.

The synthesizing device described in each embodiment can be used for projectors, in-vehicle headlights, lighting, display backlights, and the like.

1 projection device 10 light emitting unit 11 first light emitting unit 12 second light emitting unit 100 light emitting device 101 first light emitting device 102 second light emitting device
110 base
111 metal film
120 semiconductor laser element
121 first semiconductor laser element
122 second semiconductor laser element
130 Submount
140 light reflecting member
150 wire
160 protection element
170 lid member

180 glue
190 lens member
191 lens section
192 non-lens portion 103 mounting board
113 metal film
123 insulating film 20 polarization control member 21 first polarization control member 22 second polarization control member 200 dichroic mirror 201 wavelength plate 30 mirror 40 PBS
50 lens 51 diffusion lens 51
52 collimating lens 53 lens array 54 superimposing lens 60 DMD
70 prism 80 projection unit

Claims (12)

a first dichroic mirror having a first incident surface;
a second dichroic mirror having a second incident surface and being in contact with the first dichroic mirror;
a first wave plate bonded to the first incident surface;
A polarization control member, wherein a wavelength plate is not bonded to the second incident surface. a third dichroic mirror having a third incident surface and being in contact with the second dichroic mirror;
2. The polarization control member of claim 1, wherein no wave plate is bonded to the third incident surface. a first dichroic mirror having a first incident surface;
a second dichroic mirror having a second incident surface and being in contact with the first dichroic mirror;
a third dichroic mirror having a third incident surface and being in contact with the second dichroic mirror;
a first wave plate bonded to the first incident surface;
a second wave plate bonded to the second incident surface;
A polarization control member, wherein a wave plate is not bonded to the third incident surface. 4. The polarization control member according to claim 2, wherein the first dichroic mirror, the second dichroic mirror, and the third dichroic mirror are arranged in this order. The first dichroic mirror has a first reflecting surface that intersects with the first incident surface, the second dichroic mirror has a second reflecting surface that intersects with the second incident surface,
The first reflecting surface reflects light having a first wavelength condition, the second reflecting surface reflects light having a second wavelength condition,
5. The polarization control member according to claim 1, wherein said first reflecting surface and said second reflecting surface are parallel. a first semiconductor laser element;
a second semiconductor laser element;
a polarization control member,
The polarization control member is
a first dichroic mirror having a first incident surface on which light emitted from the first semiconductor laser element is incident;
a second dichroic mirror having a second incident surface on which light emitted from the second semiconductor laser element is incident;
a wave plate bonded to the first incident surface;
The light-emitting device, wherein the wavelength plate has an incident surface, and the light emitted from the first semiconductor laser element is incident on the incident surface before entering the first incident surface. the polarization direction of the light emitted from the first semiconductor laser element is different from the polarization direction of the light emitted from the second semiconductor laser element,
7. The polarization direction of the light emitted from the first semiconductor laser element after passing through the polarization control member is the same as the polarization direction of the light emitted from the second semiconductor laser element. Luminescent device. The first dichroic mirror has a first reflecting surface that reflects light emitted from the first semiconductor laser element,
the second dichroic mirror has a second reflecting surface that reflects light emitted from the second semiconductor laser element,
8. The light emitting device according to claim 6 , wherein said first reflecting surface transmits light reflected by said second reflecting surface. a third semiconductor laser element,
The polarization control member further has a third dichroic mirror,
the third dichroic mirror has a third incident surface on which light emitted from the third semiconductor laser element is incident and a third reflecting surface on which the light is reflected;
9. The light emitting device according to claim 8 , wherein said first reflecting surface and said second reflecting surface transmit light reflected by said third reflecting surface. 10. The light emitting device according to claim 9, wherein said first semiconductor laser element, said second semiconductor laser element, and said third semiconductor laser element emit red light, blue light, and green light, respectively. a lens member comprising a first lens portion and a second lens portion;
the first lens section and the second lens section collimate the light emitted from the first semiconductor laser element and the light emitted from the second semiconductor laser element, respectively;
The light emitting device according to any one of claims 6 to 10, wherein the polarization control member changes the polarization direction of light emitted from the lens member. further comprising a translucent cover member through which the light emitted from the first semiconductor laser element and the second semiconductor laser element passes;
12. The light emitting device according to claim 11, wherein said lens member is bonded to said lid member.

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