JP2008139381A - Wavelength conversion element, light source device, projector and monitor device - Google Patents

Abstract

A wavelength conversion element, a light source device, and a projector capable of widening a permissible range of wavelengths to be converted even when output wavelengths vary among light emitting units without reducing the overall conversion efficiency. To provide.
A wavelength conversion element that receives a plurality of laser beams emitted from a plurality of light emitting units, converts each of the plurality of laser beams into a predetermined wavelength, and emits the converted light. Correspondingly, a plurality of light passage regions L are provided, and the plurality of light passage regions L have a repeating structure of domains whose polarizations are reversed from each other along the central axis of the laser light emitted from the plurality of light emitting units. In addition, the width in the central axis direction of the laser light of each domain of the plurality of light passing regions L is different along the arrangement direction K of the plurality of light emitting units.
[Selection] Figure 3

Description

  The present invention relates to a wavelength conversion element, a light source device, a projector, and a monitor device.

In recent years, coherent light sources have become indispensable in measurement fields such as image display devices, optical communication fields, medical fields, and microscopes. Various wavelengths of coherent light are used depending on the purpose.
Therefore, wavelength conversion elements using the nonlinear optical effect are used in many fields because the wavelength used by the laser light source can be expanded by converting the wavelength of light by wavelength conversion. In wavelength conversion of light using such a nonlinear optical effect, it is necessary to satisfy a phase matching condition between the fundamental wave before conversion and the harmonic wave after conversion, and the pseudo-polarization in which the polarization direction is periodically reversed. A phase matching method is used. However, since the wavelength conversion element actually has an extremely narrow wavelength tolerance that satisfies the phase matching condition, if the wavelength of the fundamental wave is shifted, the output is extremely reduced.

A semiconductor laser used as a light source is manufactured on a wafer, cut out by dicing, and manufactured as a chip. There is a manufacturing variation within the wafer surface, and there is a problem that the characteristics differ depending on the location where the wafer is cut out. In order to solve this problem, there has been proposed a wavelength conversion element in which periodic structures having different polarization pitches are made in the traveling direction of laser light in the wavelength conversion element (see, for example, Patent Document 1).
The wavelength conversion element described in Patent Document 1 is an element in which a domain-inverted layer is formed that is divided into three regions in the light traveling direction and has a different period for each region. In this way, the wavelength tolerance of the wavelength conversion element is increased in response to variations in the output wavelength of the semiconductor laser.
JP-A-5-273623

  However, since the efficiency of wavelength conversion is proportional to the element length, in the wavelength conversion element described in Patent Document 1, the length of the wavelength conversion element is the part that does not match the phase matching condition as the period of the polarization pitch. Since they are mixed in the direction, there arises a problem that the overall conversion efficiency is lowered.

  The present invention has been made in order to solve the above-described problem, and even if there is variation in the output wavelength of each light emitting unit without reducing the overall conversion efficiency, the allowable range of the wavelength to be converted An object of the present invention is to provide a wavelength conversion element, a light source device, and a projector that can widen the range.

In order to achieve the above object, the present invention provides the following means.
The wavelength conversion element of the present invention converts a part of wavelengths of laser light emitted from a light emitting unit having a plurality of light emitting units into respective predetermined wavelengths, and the light converted into the predetermined wavelengths, The laser light that has not been converted to the predetermined wavelength is emitted, and a plurality of light passing regions are provided corresponding to each of the plurality of light emitting units, and the plurality of light passing regions are emitted from the plurality of light emitting units. A domain having a repetitive domain whose polarizations are reversed with respect to each other along the central axis of the laser beam, and the width of each of the plurality of light passing regions in the central axis direction of the laser beam It differs along the arrangement direction of the light emitting parts.

First, the light emitting part may have a peak wavelength of about several nanometers different due to manufacturing errors or the like. At this time, in the wavelength conversion element according to the present invention, a plurality of light passage regions are provided corresponding to each of the plurality of light emitting units. And since the width of the central axis direction of the laser beam of each domain of the plurality of light passing regions is different, the light passing region which is the width of the domain whose wavelength coincides with or is close to the peak wavelength of the light emitting part Light can be incident on the.
In this way, by making the light incident in accordance with the light passage region that is the width of the domain for converting the wavelength that matches or is close to the peak wavelength of the light emitting portion, the light is converted without reducing the intensity of the incident light. The allowable range of wavelengths can be widened.

  In the wavelength conversion element of the present invention, each of the plurality of light passing regions is divided into a plurality of light conversion regions, and the width of the laser beam in the central axis direction of each of the domains of the plurality of light conversion regions is Each is preferably different.

  In the wavelength conversion element according to the present invention, a plurality of light conversion regions having a domain width based on a variation in wavelength of emitted light for each light emitting section are formed. Thereby, light can be made to enter into the light conversion area | region according to the wavelength of the light inject | emitted from a light emission part. In this way, by dividing the light passage region into a plurality of light conversion regions, it becomes easy to align the light emitting portion and the wavelength conversion element, and it is possible to obtain a predetermined wavelength with a simple configuration without reducing the intensity of incident light. Can be converted.

  In the wavelength conversion element of the present invention, it is preferable that the width in the central axis direction of the laser light of the domains of the plurality of light passing regions continuously change along the arrangement direction of the plurality of light emitting units.

  In the wavelength conversion element according to the present invention, it is possible to correspond to a light emitting unit having a peak wavelength in a predetermined wavelength band by continuously changing the domain width of each light passage region. That is, as long as the light emitting part has a peak wavelength within a predetermined wavelength band, the light passing part having the width of the domain for converting the wavelength that matches the peak wavelength can be used regardless of the light emitting part having any peak wavelength. The wavelength of the light emitted from the light emitting unit can be converted. Therefore, the wavelength conversion element of the present invention can convert the wavelength of the light emitted from the light emitting unit without further reducing the intensity of the incident light.

  In the wavelength conversion element of the present invention, it is preferable that the pitch of the plurality of light passage regions is the same as the pitch of the plurality of light emitting units.

  In the wavelength conversion element according to the present invention, since the pitch of the plurality of light passing regions is the same as the pitch of the plurality of light emitting units, the light passing region of the domain in which the wavelength that matches or is close to the peak wavelength of the light emitting unit is converted. When the laser beam is incident in accordance with the above, it is easy to align the light emitting portion and the wavelength conversion element.

  The light source device of the present invention selects a plurality of light emitting units that emit laser light, the wavelength conversion element, and laser light that has not been converted to the predetermined wavelength from laser light emitted from the wavelength conversion element. And a wavelength selection element that functions as a resonator mirror of the light emitting part by reflecting the light toward the light emitting part and transmits the remaining laser light.

In the light source device according to the present invention, part of the laser light emitted from the plurality of light emitting units is converted into a predetermined wavelength by the wavelength conversion element. The light converted to the predetermined wavelength and the light not converted to the predetermined wavelength are emitted to the wavelength selection element, and the predetermined selection wavelength light is reflected by the wavelength selection element and the converted light is transmitted. . The light reflected by the wavelength selection element resonates and amplifies between the resonator mirrors, and further passes through the wavelength conversion element, whereby the converted light is emitted.
At this time, as described above, even if there is a variation in the peak wavelength of the light emitting part due to manufacturing errors or the like, the light passing that has the width of the domain that matches or is close to the peak wavelength of the light emitting part Light is incident according to the region. In this way, when the light emitted from the plurality of light emitting units is incident on the wavelength conversion element, it is emitted to the wavelength selection element without reducing the intensity. Therefore, since the light conversion efficiency of the wavelength conversion element is high, it is possible to improve the light use efficiency of the entire apparatus.

  A projector according to the present invention includes the light source device described above, a light modulation device that modulates light emitted from the light source device in accordance with an image signal, and a projection device that projects an image formed by the light modulation device. It is characterized by that.

  In the projector according to the present invention, the light emitted from the light source device enters the light modulation device. Then, the image formed by the light modulation device is projected by the projection device. At this time, since the light emitted from the light source device has a high light conversion efficiency of the wavelength conversion element as described above, a bright image can be displayed by providing the light source device in the projector.

  A monitor device according to the present invention includes the light source device described above and an imaging unit that images a subject with light emitted from the light source device.

  In the monitor device according to the present invention, the light emitted from the light source device irradiates the subject, and the subject is imaged by the imaging means. At this time, since the light emitted from the light source device has high light conversion efficiency of the wavelength conversion element as described above, the subject is irradiated with bright light. Therefore, the subject can be clearly imaged by the imaging means.

  Hereinafter, embodiments of a wavelength conversion element, a light source device, a projector, and a monitor device according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the light source device 10 according to the present invention is converted by a semiconductor laser chip 11, a wavelength conversion element 12 that converts the wavelength of light emitted from the semiconductor laser chip 11, and the wavelength conversion element 12. A wavelength selection element 13 that transmits light and selectively reflects light having a wavelength that has not been converted is provided. FIG. 1 is a diagram showing a schematic configuration of the light source device 10.

As shown in FIG. 1, the semiconductor laser chip 11 includes five emitters (semiconductor lasers: LD) 11a, 11b, 11c, 11d, and 11e that emit laser light. The peak wavelengths of the light emitted from the emitters 11a to 11e are the same.
As shown in FIG. 2, the semiconductor laser chip 11 is fabricated on a wafer 20, cut out by dicing, and manufactured as a chip.

  A wavelength conversion element (second harmonic generation element, SHG: Second Harmonic Generation) 12 is a non-linear optical element that converts incident light into a substantially half wavelength as shown in FIG. Light W <b> 3 emitted from the semiconductor laser chip 11 and directed to the wavelength selection element 13 is converted into light having a substantially half wavelength by passing through the wavelength conversion element 12. The wavelength conversion efficiency by the wavelength conversion element 12 has a non-linear characteristic. For example, the higher the intensity of the laser light incident on the wavelength conversion element 12, the better the conversion efficiency. That is, not all of the laser light emitted from the semiconductor laser chip 11 is converted into laser light having a predetermined wavelength.

Next, details of the wavelength conversion element 12 will be described.
A plate-shaped element is used as the wavelength conversion element 12. As shown in FIG. 1, the wavelength conversion element 12 is divided into a plurality of light passage regions L corresponding to the emitters 11a to 11e. As shown in FIG. 3, each light passage region L is divided into a first light conversion region L1, a second light conversion region L2, and a third light conversion region L3 along the arrangement direction K of the emitters 11a to 11e. It is divided. All of the first to third light conversion regions L1 to L3 have the same width in the arrangement direction K of the emitters. The pitch P1 between the adjacent light passing regions L is equal to the pitch P2 between the emitter 11a to the emitter 11e of the semiconductor laser chip 11.
The wavelength conversion element 12 has a polarization periodic structure for each of the first to third light conversion regions L1 to L3, that is, a repeated structure of domains in which the polarizations are mutually inverted. The light is transmitted through the polarization periodic structure, so that the wavelength of the incident light is converted. The width (hereinafter referred to as “pitch”) of the laser light in each domain of the first to third light conversion regions L1 to L3 of the wavelength conversion element 12 is the same from the incident end surface 13a to the exit end surface 13b. The pitch. The pitches of the light conversion regions L1 to L3 are different from each other and are Λ1, Λ2, and Λ3.

Such a polarization periodic structure can be manufactured, for example, by applying a manufacturing method described in JP-A-4-19719. That is, first, a striped electrode pattern is formed on a substrate made of a nonlinear ferroelectric material (for example, LiTaO ₃ ) in which regions having electrodes and regions without electrodes are alternately arranged along the central axis O direction of the laser beam. . At this time, the width of each electrode pattern and the interval between the electrode patterns are optimized so that the pitch of each domain in the first to third light conversion regions L1 to L3 is Λ1, Λ2, and Λ3, respectively. That is, the width and interval of the electrode pattern are different in the first to third light conversion regions L1 to L3. Next, by applying a pulse voltage to these electrode patterns, a polarization periodic structure as shown in FIG. 3 is obtained. After forming the polarization periodic structure in this manner, the normal electrode pattern is removed, but it may be left as it is.

Thus, the wavelength conversion element 12 has a polarization inversion structure with a different period (pitch) in each of the first to third light conversion regions L1 to L3. The pitches [Lambda] 1, [Lambda] 2, [Lambda] 3 of each domain are pitches that are converted to wavelengths based on variations in output wavelength due to manufacturing errors of the semiconductor laser chip 11. Specifically, the wavelength when using a blue laser light source device will be described as an example. For example, the peak wavelength of light emitted from the semiconductor laser chip 11 is designed to be 920 nm. However, as shown in FIG. 2, the semiconductor laser chip 11 in the region A due to manufacturing variations of the semiconductor laser chip 11 on the wafer 20. The wavelength λ01 of the light emitted from the emitter 11a to the emitter 11e is 920 nm and the wavelength λ02 of the light emitted from the emitter 11a to the emitter 11e of the semiconductor laser chip 11 in the region B is 918 nm. In some cases, the wavelength λ03 of light emitted from the emitters 11a to 11e of the semiconductor laser chip 11 is 916 nm.
Therefore, a domain pitch Λ1 is formed in the first light conversion region L1 so as to convert the wavelength of the light of wavelength λ01, and the wavelength λ1 of the light that has passed through the first light conversion region L1 is converted to 460 nm. It has come to be. Similarly, domain pitches Λ2 and Λ3 are formed in the second and third light conversion regions L2 and L3 so as to convert the wavelengths of light having wavelengths λ02 and λ03. The wavelength λ2 of the light that has passed through the light conversion regions L2 and L3 is converted to 459 nm, and λ3 is converted to 458 nm.
However, the wavelengths listed here are merely examples.

When the semiconductor laser chip 11 in the region A is used, the wavelength λ01 of light emitted from the emitters 11a to 11e is 920 nm. Therefore, as shown in FIG. 3, the alignment of the semiconductor laser chip 11 and the wavelength conversion element 12 is performed so that each of the emitters 11a to 11e corresponds to the first light conversion region L1. Thereby, a part of the light emitted from the emitters 11a to 11e is converted into light having a wavelength of 460 nm.
When the semiconductor laser chip 11 in the region B is used, the wavelength λ02 of light emitted from the emitters 11a to 11e is 918 nm. Therefore, as shown in FIG. 4, the wavelength conversion element 12 is shifted along the arrangement direction K so that each of the emitters 11a to 11e corresponds to the second light conversion region L2. In this way, alignment between the semiconductor laser chip 11 and the wavelength conversion element 12 is performed. Thereby, a part of the light emitted from the emitters 11a to 11e is converted to a wavelength of 459 nm.
Similarly, when the semiconductor laser chip 11 in the region C is used, the wavelength conversion element 12 is shifted along the arrangement direction K so that the emitters 11a to 11e correspond to the third light conversion region L3.
In addition to this, for example, even if the wavelengths of light emitted from the emitters 11a to 11e are other than 920 nm, 918 nm, and 916 nm, the light is incident on the first to third light conversion regions L1 to L3 having the closest wavelengths. You can do it. Thereby, the conversion efficiency by the wavelength conversion element 12 can be improved.

As shown in FIG. 1, the wavelength selection element 13 selects laser light (a chain line shown in FIG. 1) W <b> 1 emitted from the wavelength conversion element 12 and reflects it toward the semiconductor laser chip 11. Functions as a resonator mirror of the emitters 11a to 11e and transmits the converted laser beam (two-dot chain line shown in FIG. 1) W2. As the wavelength selection element 13, for example, an optical element such as a hologram having a periodic grating can be used.
The fundamental wave light (solid line shown in FIG. 1) W3 emitted from the semiconductor laser chip 11 is repeatedly reflected and amplified between the semiconductor laser chip 11 and the wavelength selection element 13, and then is converted into a laser beam W2 as a wavelength. The light is emitted from the selection element 13. The wavelength selection element 13 transmits light of various wavelengths, but only light of a predetermined wavelength is amplified. The intensity of the amplified light is significantly higher than the intensity of light of other wavelengths. Therefore, the light W2 that has passed through the wavelength selection element 13 can be regarded as light having a substantially single wavelength. The wavelength of the light W2 is substantially the same as the wavelength selected by the wavelength selection element 13, that is, the wavelength of the light W1 reflected by the wavelength selection element 13. Since the wavelength selection element 13 reflects a part (about 98 to 99%) of light having a predetermined selection wavelength, the remaining light (about 1 to 2%) is used as output light.
The wavelength selection element 13 selects only the laser light W1 that has not been converted to a predetermined wavelength by the wavelength conversion element 12, reflects it toward the semiconductor laser chip 11, and transmits the other laser light. .

In the wavelength conversion element 12 according to the present embodiment, the light emitted from the semiconductor laser chip 11 is appropriately obtained by dividing the first to third light conversion regions L1 to L3 in which the domain pitches Λ1, Λ2, and Λ3 are formed. It is possible to pass through the first to third light conversion regions L1 to L3 having a wide domain width. That is, since the phase matching condition of the wavelength conversion element 12 can be satisfied, even if the wavelength of light emitted from the emitter 11a to the emitter 11e is different for each semiconductor laser chip 11 due to a manufacturing error or the like, the wavelength conversion element 12 The light can be converted into a predetermined wavelength without reducing the intensity of the light incident on.
Further, since the pitch P1 of the light passage region L matches the pitch P2 between the emitter 11a to the emitter 11e of the semiconductor laser chip 11, the alignment between the semiconductor laser chip 11 and the wavelength conversion element 12 is facilitated.
That is, even if the output wavelength varies for each semiconductor laser chip 11, it is possible to widen the allowable range of the converted wavelength.
Further, in the light source device 10, it is possible to improve the light use efficiency by using the wavelength conversion element 12 with high conversion efficiency.

In addition, although the pitch P1 of the light passage region L is the same as the pitch P2 between the emitter 11a to the emitter 11e of the semiconductor laser chip 11, it does not necessarily have to be the same. That is, when the wavelength conversion element 12 is moved, the pitch P2 between the emitters 11a to 11e of the semiconductor laser chip 11 is within a range that can be disposed at positions facing the respective light conversion regions L1 to L3. You don't have to. Therefore, any light emitting part having a pitch within such a range can be applied to the wavelength conversion element 12 of the present invention.
Further, although the semiconductor laser chip 11 in which a plurality of emitters are formed on one chip is used, a semiconductor laser chip in which emitters are individually formed may be used. In this configuration, it is possible to improve the conversion efficiency by arranging individual emitters in the light conversion region corresponding to the peak wavelength of the emitters. Furthermore, a plurality of emitters can be arranged by using individual emitters having variations and arranging them in correspondence with the light conversion regions corresponding to the peak wavelengths. This makes it possible to provide a light source device that emits bright light.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. In each embodiment described below, portions having the same configuration as those of the light source device 10 according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
The light source device 30 according to the present embodiment is different from the first embodiment in the domain pitch in the light passage region M.

As shown in FIG. 5A, the wavelength conversion element 31 is divided into a plurality of light passing regions M along the arrangement direction K of the emitters 11a to 11e. In each light passage region M, as shown in the enlarged view of FIG. 5B, the width of the domain laser light in the direction of the central axis O in the direction P is continuously increased. That is, the pitch of each domain on the one end 31a side of the light passing region M is Λ1, and the pitch of each domain on the other end 31b side is Λ2. The domain pitch changes smoothly (continuously) from the one end 31a side to the other end 31b side, that is, from the pitch Λ1 to the pitch Λ2.
Thus, the wavelength conversion element 31 has a polarization inversion structure in which the period (pitch) continuously changes in each light passage region M. The pitches Λ1 and Λ2 of each domain are pitches that are converted into wavelengths based on variations in output wavelength due to manufacturing errors of the semiconductor laser chip 11. Specifically, the wavelength when using a blue laser light source device will be described as an example. For example, the peak wavelength of the light emitted from the semiconductor laser chip 11 is designed to be 920 nm, but the wavelength of the light emitted from the semiconductor laser chip 11 varies in the range of λ01 = 915 nm to λ02 = 925 nm. There is.

  Therefore, a domain pitch Λ1 is formed on the one end 31a side of the light passage region M so as to convert light of wavelength λ01 (915 nm), and the wavelength of the light that has passed through the one end 31a side of the light passage region M. λ1 is converted to 457.5 nm. Similarly, a domain pitch Λ2 is formed on the other end 31b side of the light passage region M so as to convert light of wavelength λ02 (925 nm), and the other end 31b side of the light passage region M is disposed on the other end 31b side. The wavelength λ2 of the transmitted light is converted to 462.5 nm. Therefore, alignment of the semiconductor laser chip 11 and the wavelength conversion element 31 is performed so that light is incident on a position having a domain pitch corresponding to the wavelength of light emitted from the emitters 11 a to 11 e of each semiconductor laser chip 11. I do. Thereby, a part of the light emitted from the emitters 11a to 11e is converted into a predetermined wavelength.

In the light source device 30 according to the present embodiment, the same effects as those of the wavelength conversion element 12 and the light source device 10 of the first embodiment can be obtained. Furthermore, in the wavelength conversion element 31 and the light source device 30 of the present embodiment, the semiconductor laser chip that emits light within a predetermined wavelength band by continuously changing the domain pitch of each light passing region M from Λ1 to Λ2. 11. That is, in the case of the semiconductor laser chip 11, light is incident on the width and position of the domain where the wavelength matching the peak wavelength of the semiconductor laser chip 11 is converted, thereby converting the incident light without further reducing the intensity. be able to. Thereby, when there are many variations in the wavelength of the light emitted from the semiconductor laser chip 11, it is possible to cope with a plurality of types of wavelengths, which is effective.
In addition, the wavelength conversion element which combined the wavelength conversion element 12 of 1st Embodiment and the wavelength conversion element 31 of 2nd Embodiment may be sufficient. That is, a light conversion region where the width of the laser beam in the central axis direction of the domain changes stepwise and a light conversion region where the width continuously changes may be mixed.

[Third Embodiment]
Next, a third embodiment according to the present invention will be described with reference to FIG.
In the present embodiment, a projector 100 including the light source device 10 of the first embodiment will be described. In FIG. 6, the casing constituting the projector 100 is omitted for simplification.

In the projector 100, the red laser light source (light source device) 11R that emits red light, green light, and blue light, the green laser light source (light source device) 11G, and the blue laser light source (light source device) 11B are the same as those in the first embodiment. The light source device 10 is used.
Further, the projector 100 emits light from the liquid crystal light valves (light modulation devices) 104R, 104G, and 104B that modulate the laser light emitted from the laser light sources 11R, 11G, and 11B, and the liquid crystal light valves 104R, 104G, and 104B, respectively. A projection lens (projection device) 107 that magnifies and projects an image formed by a cross dichroic prism (color light synthesis means) 106 that synthesizes light and guides it to the projection lens 107 and the liquid crystal light valves 104R, 104G, and 104B. And.

  Further, in order to make the illuminance distribution of the laser light emitted from the laser light sources 11R, 11G, and 11B uniform, the projector 100 makes the uniformizing optical systems 102R, 102G downstream of the laser light sources 11R, 11G, and 11B in the optical path. , 102B are provided, and the liquid crystal light valves 104R, 104G, 104B are illuminated by light having a uniform illuminance distribution. For example, the uniformizing optical systems 102R, 102G, and 102B are configured by, for example, a hologram 102a and a field lens 102b.

  The three color lights modulated by the respective liquid crystal light valves 104R, 104G, and 104B are incident on the cross dichroic prism 106. This prism is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged in a cross shape on the inner surface thereof. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 110 by the projection lens 107, which is a projection optical system, and an enlarged image is displayed.

  In the projector 100 of this embodiment described above, the light emitted from the red laser light source 11R, the green laser light source 11G, and the blue laser light source 11B is emitted to the uniformizing optical systems 102R, 102G, and 102B without decreasing the intensity. Therefore, the light projected by the projection lens 107 is bright light. Therefore, a clear image can be displayed on the screen 110.

  In the projector of this embodiment, the red, green, and blue laser light sources 11R, 11G, and 11B have been described using the light source device 10 of the first embodiment, but the light source device 30 of the second embodiment. It is also possible to use. At this time, the light source device of a different embodiment can be adopted for each light source device 10, or the light source device of the same embodiment can be adopted.

Further, although a transmissive liquid crystal light valve is used as the light modulator, a light valve other than liquid crystal may be used, or a reflective light valve may be used. Examples of such a light valve include a reflective liquid crystal light valve and a digital micromirror device. The configuration of the projection optical system is appropriately changed depending on the type of light valve used.
The light source devices 10 and 30 of the first and second embodiments are also applied to a scanning image display device. An example of such an image display device is shown in FIG. The image display device 200 illustrated in FIG. 7 includes the light source device 10 according to the first embodiment, the MEMS mirror (scanning unit) 202 that scans the light emitted from the light source device 10 toward the screen 210, and the light source device 10. A condensing lens 203 that condenses the emitted light on the MEMS mirror 202 is provided. The light emitted from the light source device 10 is guided to scan the screen 210 in the horizontal direction and the vertical direction by moving the MEMS mirror 202. In the case of displaying a color image, a plurality of emitters constituting the semiconductor laser chip 11 may be configured by a combination of emitters having red, green, and blue peak wavelengths.

[Fourth Embodiment]
Next, a configuration example of the monitor device 300 to which the light source device 10 according to the first embodiment is applied will be described. FIG. 8 is a schematic diagram showing an outline of the monitor device. The monitor device 300 includes a device main body 310 and an optical transmission unit 320. The apparatus main body 310 includes the light source device 10 of the first embodiment described above.

  The light transmission unit 320 includes two light guides 321 and 322 on the light sending side and the light receiving side. Each of the light guides 321 and 322 is a bundle of a large number of optical fibers, and can send laser light to a distant place. The light source device 10 is disposed on the incident side of the light guide 321 on the light transmission side, and the diffusion plate 323 is disposed on the emission side thereof. The laser light emitted from the light source device 10 is transmitted to the diffusion plate 323 provided at the tip of the light transmission unit 320 through the light guide 321 and is diffused by the diffusion plate 323 to irradiate the subject.

  An imaging lens 324 is also provided at the tip of the light transmission unit 320, and reflected light from the subject can be received by the imaging lens 324. The received reflected light travels through the light guide 322 on the receiving side and is sent to a camera 311 as an imaging means provided in the apparatus main body 310. As a result, an image based on the reflected light obtained by irradiating the subject with the laser light emitted from the light source device 10 can be captured by the camera 311.

  According to the monitor device 300 configured as described above, the subject can be irradiated by the high-output light source device 10, so that the brightness of the captured image obtained by the camera 311 can be increased.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the third and fourth embodiments, the light source device 10 having the same structure as that of the first embodiment is used. Instead, the light source device 10 having the same structure as that of the second embodiment is used. You may do it.

It is a top view which shows the light source device which concerns on 1st Embodiment of this invention. It is a perspective view which shows the wafer before the light emission part of FIG. 1 is diced. It is a top view which shows the wavelength conversion element of FIG. It is the top view which moved the wavelength conversion element of the light source device which concerns on 1st Embodiment of this invention. It is a top view which shows the light source device which concerns on 2nd Embodiment of this invention. It is a top view which shows the projector which concerns on 3rd Embodiment of this invention. It is a top view which shows the modification of the projector which concerns on 3rd Embodiment of this invention. It is a top view which shows the monitor apparatus which concerns on 3rd Embodiment of this invention.

Explanation of symbols

  L1 to L3... Light conversion region, P1... Pitch of light passage region L, P2... Pitch between emitters of light emitting part, 10, 30... Light source device, 11a to 11e. Element 13 ... Wavelength selection element 100 ... Projector 104R, 104G, 104B ... Liquid crystal light valve (light modulation device) 107 ... Projection lens (projection device) 300 ... Monitor device 311 ... Camera (imaging means)

Claims (7)

A plurality of laser beams emitted from a plurality of light emitting units are incident, a wavelength conversion element that converts each of the plurality of laser beams into a predetermined wavelength and emits it,
A plurality of light passage regions are provided corresponding to each of the plurality of light emitting units,
The plurality of light passage regions have a repeating structure of domains whose polarizations are reversed with respect to each other along a central axis of laser light emitted from the plurality of light emitting units, and each of the plurality of light passage regions 2. The wavelength conversion element according to claim 1, wherein a width of the laser beam in a central axis direction of the domain is different along an arrangement direction of the plurality of light emitting units. Each of the plurality of light passage regions is divided into a plurality of light conversion regions,
2. The wavelength conversion element according to claim 1, wherein a width of each of the plurality of light conversion regions in a direction of a central axis of the laser light is different.   2. The wavelength conversion element according to claim 1, wherein a width in a central axis direction of the laser light of the domains of the plurality of light passing regions continuously changes along an arrangement direction of the plurality of light emitting units. .   4. The wavelength conversion element according to claim 1, wherein pitches of the plurality of light passing regions are the same as pitches of the plurality of light emitting units. 5. A plurality of light emitting sections for emitting laser light;
The wavelength conversion element according to any one of claims 1 to 4,
The laser beam that has not been converted to the predetermined wavelength from the laser beams emitted from the wavelength conversion element is selected and reflected toward the light emitting unit to function as a resonator mirror of the light emitting unit, and the remaining And a wavelength selection element that transmits the laser beam. A light source device according to claim 5;
A light modulation device that modulates light emitted from the light source device in accordance with an image signal;
A projector comprising: a projection device that projects an image formed by the light modulation device. A light source device according to claim 5;
A monitor device comprising: imaging means for imaging a subject by light emitted from the light source device.

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