JP2015111517A - Light source device - Google Patents

Abstract

A light source device capable of sufficiently ensuring the illuminance of laser support light is provided. In this light source device 1, a condensing region of laser light L condensed in a light emitting envelope 11 by a condensing extension K is a surface intersecting the optical axis LA direction or the optical axis LA of the laser light L. Expand inward. As a result, it is possible to expand the light emission region M of the laser support light that is lit and maintained in the light emitting envelope 11, and the illuminance of the laser support light can be sufficiently ensured without increasing the output of the laser unit 2. [Selection] Figure 1

Description

  The present invention relates to a light source device.

  2. Description of the Related Art Conventionally, there is a light source device that emits ultraviolet rays while irradiating an ionized gas in a housing with laser light to maintain a plasma state. For example, in the light source described in Patent Document 1, plasma is generated by discharge between electrodes by supplying power between opposed electrodes arranged in a glass casing, and the plasma is continuously irradiated with laser light. The laser supporting light that is plasma emission is turned on and maintained.

Special table 2009-532829

  However, in the conventional light source device described above, since the minute range in which the laser is focused becomes the light emitting region of the laser support light, the laser support light has a sufficient brightness, but there is a problem that it is difficult to obtain the illuminance. It was. In order to secure the illuminance of the laser support light, it is necessary to enlarge the light emitting area. However, if the light emission area is simply enlarged, it is necessary to increase the output of the laser to turn on and maintain the laser support light. It is done.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a light source device that can sufficiently ensure the illuminance of laser support light.

  In order to solve the above problems, a light source device according to the present invention includes a laser unit that emits laser light, a light source that includes a light emitting envelope in which a light emitting gas is sealed in an internal space, and a laser light that is collected in the light emitting envelope. It is characterized by comprising an optical system that emits light, and a condensing extension portion that expands the condensing region of the laser light by the optical system in the optical axis direction of the laser light or in an in-plane direction intersecting the optical axis direction.

  In this light source device, the condensing region of the laser beam condensed in the light emitting envelope is expanded in the optical axis direction of the laser or in the in-plane direction intersecting the optical axis direction by the condensing extension portion. As a result, it is possible to expand the light emission region of the laser support light that is lit and maintained in the light emitting envelope serving as the light source, and it is possible to sufficiently ensure the illuminance of the laser support light without increasing the output of the laser part.

  Moreover, it is preferable that the condensing extension part has the condensing position formation part which forms a some condensing position in the condensing area | region of a laser beam. In this case, by forming a plurality of condensing positions, the condensing region of the laser light can be sufficiently expanded, and the illuminance of the laser supporting light can be further secured.

  Moreover, it is preferable that the condensing position formation part is comprised by the optical path length adjustment board which changes the optical path length of a part of laser beam to the optical axis direction of a laser beam with respect to the condensing position of another part. By using such an optical path length adjusting plate, a plurality of condensing positions can be formed in the laser light condensing region with a simple configuration.

  In addition, the condensing position forming unit preferably includes a plurality of optical path length adjustment plates, and the plurality of optical path length adjustment plates are preferably arranged in the optical axis direction of the laser light so that the advance positions with respect to the laser light are different from each other. . In this case, a plurality of condensing positions can be formed in the laser light condensing region with a simple configuration.

  Moreover, it is preferable to have a drive part which drives an optical path length adjustment board with respect to a laser beam. In this case, the expanded state of the condensing region of the laser beam can be made variable.

  Moreover, it is preferable that the condensing position formation part is comprised by the optical path length adjustment plate which changes the optical path length of a laser beam to the surroundings of the axis | shaft of an optical axis direction. By using such an optical path length adjusting plate, a plurality of condensing positions can be formed in the laser light condensing region with a simple configuration.

  Moreover, it is preferable that the condensing position formation part is comprised by the optical path length adjustment plate which changes the optical path length of a laser beam to the radial direction of an optical axis. By using such an optical path length adjusting plate, a plurality of condensing positions can be formed in the laser light condensing region with a simple configuration.

  Moreover, it is preferable that the condensing position formation part is comprised by the lens array. In this case, the condensing region of the laser light can be easily enlarged by the lens array.

  Moreover, it is preferable that the condensing position formation part is comprised by the light modulation element. In this case, the condensing region of the laser light can be easily expanded by the light modulation element.

  Moreover, it is preferable that the condensing extension part has the condensing shape adjustment part which extends the condensing shape in the condensing area | region of a laser beam to the in-plane direction which cross | intersects an optical axis direction. In this case, the condensing region of the laser light can be sufficiently expanded by extending the condensing shape, and the illuminance of the laser supporting light can be further secured.

  Moreover, it is preferable that the condensing shape adjustment part is comprised by the cylindrical lens. In this case, the condensing shape of the laser beam can be easily extended by the cylindrical lens.

  Moreover, it is preferable that the condensing shape adjustment part is comprised by the light modulation element. In this case, the condensing shape of the laser light can be easily extended by the light modulation element.

  According to the light source device of the present invention, the illuminance of the laser support light can be sufficiently secured.

It is a figure which shows the outline of the light source device which concerns on 1st Embodiment of this invention. It is a figure which shows the condensing area | region of the laser beam in the light source device shown in FIG. 1, (a) shows the case where a single condensing area | region is formed, (b) shows several condensing area | regions. Shows the case. It is a figure which shows the outline of the light source device which concerns on 2nd Embodiment of this invention. It is a figure which shows the modification of an optical path length adjusting plate, (a) shows the structure of an optical path length adjusting plate, (b) shows the condensing area | region of a laser beam. It is a figure which shows another modification of an optical path length adjustment board, (a) shows the structure of an optical path length adjustment board, (b) shows the condensing area | region of a laser beam. It is a figure which shows the outline of the light source device which concerns on 3rd Embodiment of this invention. It is a figure which shows the outline of the light source device which concerns on 4th Embodiment of this invention. It is a figure which shows the outline of the light source device which concerns on 5th Embodiment of this invention, (a) shows the figure seen from the front side, (b) shows the figure seen from the side surface side. It is a figure which shows the outline of the light source device which concerns on 6th Embodiment of this invention, (a) shows the case where a diffractive optical element is used as a condensing shape adjustment part, (b) is a condensing optical element. The case where it is used as a formation part is shown.

Hereinafter, a preferred embodiment of a light source device according to the present invention will be described in detail with reference to the drawings.
[First Embodiment]

  FIG. 1 is a diagram showing an outline of a light source device according to the first embodiment of the present invention. As shown in the figure, the light source device 1 houses a laser unit 2 that generates laser light L, an optical system 3 that guides the laser light L from the laser unit 2, and counter electrodes 13 and 13 that face each other. And a light emitting envelope 11 (light source 7). In the light source device 1, a light emitting envelope that is a light source 7 is generated by generating a discharge between the counter electrodes 13 and irradiating a laser beam L to a discharge region that is a region where the discharge path is highly likely to occur. 11, it is possible to generate high-luminance laser support light that is plasma light emission having a predetermined light emitting region including the condensing position F of the continuous laser light L. The laser support light extracted from the light emitting envelope 11 is used as a light source for semiconductor inspection or light for spectroscopic measurement, for example.

  The laser unit 2 is a laser diode, for example. The laser unit 2 may be either a continuous laser or a pulse laser, but a continuous laser is used in this embodiment. From the laser unit 2, for example, laser light L having a wavelength of 980 nm is emitted as a continuous wave in accordance with the absorption spectrum of the luminescent gas G. A sufficient intensity of the output of the laser light L is selected based on various optical conditions, and is about 30 W, for example. Laser light L emitted from the laser unit 2 is guided to the optical system 3 by the optical fiber 4. The optical system 3 is an optical system that condenses the laser light L from the laser unit 2 toward the light emitting envelope 11. The optical system 3 is composed of, for example, two lenses 5 and 6. The laser light L emitted from the head 4 a of the optical fiber 4 is collimated by the lens 5 and then condensed toward the light emitting envelope 11 by the lens 6 with the optical axis LA.

  More specifically, the luminescent envelope 11 includes a bulb 12 in which a luminescent gas G is sealed in a high pressure in the internal space S, and counter electrodes 13 and 13 that face each other in the internal space S. . The bulb 12 is formed into a hollow sphere with glass, for example. In the internal space S of the bulb 12, for example, xenon gas as a luminescent gas G is sealed at a high pressure. The counter electrodes 13 and 13 are formed in a rod shape from a high melting point metal such as tungsten, for example, and are opposed to each other on the tip side.

  The base end side of the counter electrode 13 passes through the wall portion of the bulb 12 and is drawn out of the bulb 12 and connected to a power supply member 14 connected to a power supply unit (not shown), thereby discharging between the electrodes. Is supplied to the counter electrodes 13 and 13. The counter electrodes 13 and 13 do not directly penetrate the wall portion of the valve 12, but a conductive member electrically connected to the counter electrodes 13 and 13 penetrates the wall portion of the valve 12 to the outside of the valve 12. It may be pulled out and connected to the power supply member 14.

  In the light source device 1 as described above, a high voltage is applied between the counter electrodes 13 and 13 through the power supply member 14, thereby forming a discharge region between the counter electrodes 13 and 13. The inner light emission gas G is ionized and converted into plasma. By irradiating the discharge region with the laser light L, the high-luminance laser support light is turned on, and by continuing the irradiation of the laser light L to the laser support light, power supply to the counter electrodes 13 and 13 is achieved. Even if it is stopped, the laser beam is maintained by receiving the energy supply from the laser beam L. Note that the laser beam L may be condensed in advance in the discharge region, and then the discharge region may be formed between the counter electrodes 13 and 13. Furthermore, after the laser supporting light is turned on, the power supply to the counter electrodes 13 and 13 may be stopped, or the power supply may be continued.

  Here, the light source device 1 is provided with a condensing extension portion K that extends a condensing region of the laser light L by the optical system 3. In the present embodiment, the condensing extension portion K is a condensing position forming portion 22 that forms a plurality of condensing positions in the condensing region of the laser light L. More specifically, as shown in FIG. 1, the condensing position forming unit 22 includes an optical path length adjusting plate 23 that is transmissive to the laser light L, and an optical path length adjusting plate 23 that is a laser optical path of the laser light L. And an actuator (driving unit) 24 that moves forward and backward.

  The optical path length adjusting plate 23 is a flat plate member having a uniform thickness of about 1 mm to 2 mm made of, for example, synthetic quartz glass, and has a light refractive index different from the atmosphere of the laser optical path outside the light emitting envelope 11. And a transparent medium having sufficient transparency with respect to the laser light L. The base end side of the optical path length adjusting plate 23 is fixed to the actuator 24, and the optical path length adjusting plate 23 is driven in a direction substantially orthogonal to the optical axis LA of the laser light L by driving the actuator 24. Yes. When the laser beam L is turned on by the laser beam L, the actuator 24 performs laser operation on the optical system 3, more specifically, on the laser beam path between the lens 6 and the light emitting envelope 11, as shown in FIG. Only approximately half of the light L passes through the optical path length adjusting plate 23, that is, in the cross section of the laser light L in the direction perpendicular to the optical axis LA of the laser light L, so as to cover a region of approximately half of the cross section. The tip end side of the optical path length adjusting plate 23 is advanced with respect to the laser beam L.

  As the optical path length adjusting plate 23 advances, the laser light L includes a component that passes through the optical path length adjusting plate 23 and a component that does not pass, and the focal position changes in each component. Thereby, the laser beam L has two condensing positions Fa and Fb in the light emitting envelope 11 on the optical axis LA. The condensing position Fa of the component passing through the optical path length adjusting plate 23 is the front side (the lower side in FIG. 1) of the laser light L in the direction of the optical axis LA, compared to the condensing position Fb of the component not passing through the optical path length adjusting plate 23. ). Therefore, as shown in FIG. 2 (a), the laser support where the condensing region of the laser light L is expanded in the direction of the optical axis LA by the two condensing positions Fa and Fb, and is lit and maintained in the light emitting envelope 11. Since the light emission region M can be expanded in the direction of the optical axis LA, the illuminance of the laser support light can be sufficiently ensured without increasing the output of the laser unit 2.

  Further, when the thickness of the optical path length adjusting plate 23 is further increased, the distance between the condensing position Fa and the condensing position Fb can be further increased. In this case, as shown in FIG. 2B, the light emitting region M of the laser supporting light that is lit and maintained in the light emitting envelope 11 can be separated. In this case as well, the illuminance of the laser support light can be sufficiently secured, and the multipoint simultaneous measurement of the inspection object or the like can be performed by using the laser support light having the light emitting areas M and M as the bright spots separately. It becomes possible.

In the light source device 1, the actuator 24 can move the optical path length adjusting plate 23 back and forth with respect to the laser light L, and the expansion state of the condensing region of the laser light L is variable. Therefore, when the illuminance of the laser support light is required, the optical path length adjustment plate 23 is advanced with respect to the laser light L, and when the brightness of the laser support light is required, the optical path length adjustment plate 23 is retracted from the laser light L. By doing so, the light source device 1 can be adapted to various usage modes.
[Second Embodiment]

  FIG. 3 is a diagram showing an outline of a light source device according to the second embodiment of the present invention. As shown in the figure, in the light source device 31 according to the second embodiment, instead of the counter electrodes 13 and 13, a metal structure (electron emission structure) 35 containing an electron emission material is placed in the light emitting envelope 11. This is different from the first embodiment in that the light source 7 is provided. In the light source device 31, when the metal structure 35 is irradiated with the continuous laser light L, plasma by the luminescent gas G is generated in the irradiation region of the continuous laser light L in the vicinity of the metal structure 35. Note that plasma is generated when electrons emitted from the metal structure 35 by irradiation of the continuous laser light L ionize the light emission gas G and the ionized light emission gas G is irradiated with the continuous laser light L. It is guessed. Then, by continuously irradiating the generated plasma with continuous laser light L (continuously supplying laser energy to the plasma), the continuous laser light L is collected in the light emitting envelope 11 as the light source 7. It is possible to turn on and maintain high-luminance laser support light that is plasma light emission having a predetermined light-emitting region including the light position F. The light source device 31 is different from the first embodiment in that a plurality of optical path length adjusting plates 23 are used.

  In the present embodiment, the bulb 12 protrudes in a columnar shape from a spherical portion (main body portion) 12a having a spherical outer diameter and a spherical inner space S, and a part of the spherical portion 12a. And a protruding portion (protruding portion) 12b. The metal structure 35 is entirely accommodated in the internal space S of the bulb 12, and is formed of a high melting point metal such as tungsten, and includes an electron emitting portion 35a containing, for example, barium as an easily radiating substance, and an electron. And a support portion 35b that supports the radiation portion 35a. The electron emitting portion 35 a irradiated with the laser light L is formed in, for example, a thin cylindrical shape, and is arranged inside the spherical portion 12 a so that the tip 35 c serving as the incident portion of the laser light L faces the top of the bulb 12. Has been. The incident portion of the laser light L to the bulb 12 is not limited to the upper surface portion of the bulb 12 and may be a side portion of the bulb 12. Further, the incident part of the laser beam L to the metal structure 35 is not limited to the tip 35c, but may be a side part of the electron emitting part 35a.

  On the other hand, the support part 35b has a rod-shaped member 37 formed in a cylindrical shape from a high melting point metal such as molybdenum, for example. The electron emitting portion 35a (tip 35c) is arranged at a desired position (here, a position that coincides with a condensing position Fd described later) in the inner space S in the spherical portion 12a on the tip side of the support portion 35b. The base end side of the support portion 35b is disposed in the internal space S in the protruding portion 12b. Note that the electron emitting portion 35a and the support portion 35b do not necessarily have to be made of different constituent materials, and the support portion 35b may be formed integrally with the material used for the electron emitting portion 35a. Further, the base may be integrally formed of the same metal, and the electron-emitting material may be contained only in the portion corresponding to the electron emitting portion 35a. Moreover, the whole electron emission part 35a and the metal structure 35 may be comprised with the easy electron emission substance itself. Furthermore, the base of the electron emission structure is not limited to a metal (conductive material) such as tungsten or molybdenum, and may be an insulator such as ceramic.

  Further, the light emitting envelope 11 has a small diameter portion 38 that holds the rod-shaped member 37 that is the support portion 35 b as the positioning portion 36 of the metal structure 35 in the internal space S of the bulb 12. The small-diameter portion 38 is provided by using a part of the inner wall of the protruding portion 12b, and the protruding portion 12b has a smaller inner diameter than the other portions so as to contact the rod-shaped member 37. The small diameter portion 38 is only in contact with the peripheral surface of the rod-shaped member 37 and is not fused to the rod-shaped member 37. Further, the small diameter portion 38 may be provided closer to the base end (lower side of the drawing) than the position illustrated in FIG. 3, or may be provided closer to the distal end side (upper side of the drawing). Further, a plurality of small diameter portions 38 may be provided.

  In the light source device 31, for example, three optical path length adjusting plates 23 </ b> A, 23 </ b> B, and 23 </ b> C are arranged at predetermined intervals in order from the laser unit 2 side along the optical axis LA of the laser light L. These optical path length adjusting plates 23A, 23B, and 23C are attached to the support member 32 so that their advance positions with respect to the laser light L in the direction perpendicular to the optical axis LA of the laser light L are different from each other on the tip side. More specifically, the degree of advance of the optical path length adjusting plates 23A, 23B, and 23C with respect to the laser light L increases in the order of the optical path length adjusting plate 23A, the optical path length adjusting plate 23B, and the optical path length adjusting plate 23C. In this case, the distance between the front end side of the optical path length adjusting plate 23A, the optical path length adjusting plate 23B, and the optical path length adjusting plate 23C and the optical axis LA of the laser beam L is increased.

  By using such optical path length adjusting plates 23A, 23B, and 23C, the laser beam L is condensed in the light emitting envelope 11 by a condensing position Fa by a component that does not pass through any of the optical path length adjusting plates 23A, 23B, and 23C. A condensing position Fb by a component passing only through the optical path length adjusting plate 23A, a condensing position Fc by a component passing through the optical path length adjusting plates 23A and 23B, and a condensing position by a component passing through all of the optical path length adjusting plates 23A, 23B and 23C Four condensing positions of Fd are provided in the direction of the optical axis LA.

  Therefore, in the light source device 31, the light condensing region of the laser light L is expanded in the direction of the optical axis LA by these four condensing positions Fa to Fd, and the light emitting region of the laser supporting light that is lit and maintained in the light emitting envelope 11. Since M can be expanded in the direction of the optical axis LA, the illuminance of the laser support light can be sufficiently ensured without increasing the output of the laser unit 2.

The optical path length adjusting plates 23A, 23B, and 23C may be attached to the support member 32 so that the advance positions of the laser light L in the direction perpendicular to the optical axis LA of the laser light L are different from each other on the tip side. Of course, the order does not matter, and the number may be changed according to the required conditions. Also in this embodiment, the thickness of the optical path length adjusting plates 23A, 23B, and 23C is increased as in the first embodiment, and the light emitting region M of the laser support light that is lit and maintained in the light emitting envelope 11 is provided. It may be separated. Further, the support member 32 may be attached to the actuator 24, and the expanded state of the condensing region of the laser light L may be variable.
[Modification of optical path length adjustment plate]

  In the said embodiment, although the optical path length adjustment plate which consists of a flat transparent medium which has uniform thickness was illustrated, an optical path length adjustment plate can take a various modification. FIG. 4A is a diagram showing a modification of the optical path length adjusting plate. As shown in the figure, the optical path length adjusting plate 33 according to the modification is formed in a disc shape by a transparent medium such as synthetic quartz glass so that the optical axis LA of the laser light L passes through the center O thereof. Is arranged. The optical path length adjusting plate 33 has a portion having a thickness different in the circumferential direction with a phase angle of, for example, 90 ° with respect to the center O, and the thickness is increased clockwise from the first portion 33a having the maximum thickness. A second portion 33b having the second largest thickness, a third portion 33c having the third largest thickness, and a fourth portion 33d having the smallest thickness. The optical path length adjusting plate 33 is disposed, for example, coaxially with the optical axis LA of the laser light L between the lens 6 and the light emitting envelope 11.

  When such an optical path length adjusting plate 33 is used, as shown in FIG. 4B, the laser light L is condensed in the light condensing position Fa by the component passing through the first portion 33 a in the light emitting envelope 11, and the second. The four condensing positions Fb of the condensing position Fb due to the component passing through the portion 33b, the condensing position Fc due to the component passing through the third portion 33c, and the condensing position Fd due to the component passing through the fourth portion 33d are represented by the optical axis LA. Have in the direction. Therefore, the condensing region of the laser light L can be expanded in the direction of the optical axis LA by these four condensing positions Fa to Fd. In the optical path length adjusting plate 33, instead of forming the fourth portion 33d having the minimum thickness, the portion may be a notched portion having no thickness (no transparent medium is present).

  In the optical path length adjusting plate 33, the order in which the portions having different thicknesses are arranged is not limited, and the number (phase angle) may be changed according to the required condition. Further, in the optical path length adjusting plate 33, instead of changing the thickness, materials having different optical refractive indexes may be arranged in the same manner, or similar light transmission conditions may be configured by a combination of the thickness and the material. In addition, as long as the phase angle is set with reference to a predetermined point, the outer shape does not have to be a disk shape, and the incident direction of the laser light L may be the opposite direction to the figure.

  FIG. 5A is a diagram showing another modification of the optical path length adjusting plate. As shown in the figure, the optical path length adjusting plate 34 according to another modification is formed in a disc shape by a transparent medium such as synthetic quartz glass, and the optical axis LA of the laser light L passes through the center O thereof. Are arranged to be. The optical path length adjusting plate 34 has portions having different thicknesses so as to be concentric in the radial direction with respect to the center O, and the first portion 34a having the smallest thickness in order from the center to the outside. The second portion 34b has the second largest thickness, and the third portion 34c has the largest thickness. The optical path length adjusting plate 34 is disposed, for example, coaxially with the optical axis LA of the laser light L between the lens 6 and the light emitting envelope 11.

  When such an optical path length adjusting plate 34 is used, as shown in FIG. 5 (b), the laser light L is condensed in the condensing position Fa by the portion passing through the first portion 34a, the second in the light emitting envelope 11. The three condensing positions in the optical axis LA direction include a condensing position Fb by a portion passing through the portion 34b and a condensing position Fc by a portion passing through the third portion 34c. Therefore, the condensing region of the laser light L can be expanded in the direction of the optical axis LA by these four condensing positions Fa to Fc. In the optical path length adjusting plate 34, instead of forming the first portion 34a having the smallest thickness, the portion may be a cutout portion having no thickness (no transparent medium is present).

In the optical path length adjusting plate 34, the order in which the portions having different thicknesses are arranged does not matter, and the number may be changed according to the required condition. Further, in the optical path length adjusting plate 34, instead of changing the thickness, materials having different optical refractive indexes may be arranged in the same manner, or similar light transmission conditions may be configured by a combination of the thickness and the material. Further, as long as a concentric circle is set on the basis of a predetermined point, the outer shape does not have to be a disk shape, and the incident direction of the laser light L may be opposite to the drawing.
[Third Embodiment]

  FIG. 6 is a diagram showing an outline of a light source device according to the third embodiment of the present invention. As shown in the figure, a light source device 41 according to the third embodiment is different from the first embodiment in that a lens array 43 is used as a condensing position forming unit 42 that is a condensing expansion unit K. More specifically, in the light source device 41, for example, a lens array 43 in which single convex lenses are arranged is disposed between the lenses 5 and 6.

In the light source device 41, the laser light L passes through the lens array 43, whereby the condensing positions Fa, Fb, and Fc of the laser light L are perpendicular to the optical axis LA (the laser light L in the direction perpendicular to the optical axis LA). In the in-plane direction). Therefore, the condensing region of the laser light L can be expanded in the direction orthogonal to the optical axis LA by these condensing positions Fa to Fc, and the light emitting region of the laser support light can be expanded, so that the laser unit 2 can be increased in output. The illuminance of the laser support light can be sufficiently secured.
[Fourth Embodiment]

  FIG. 7 is a schematic view showing a light source device according to the fourth embodiment of the present invention. As shown in the drawing, the light source device 51 according to the fourth embodiment is the first in that a spatial light modulator 53 that is a light modulation element is used as a light collection position forming unit 52 that is a light collection expansion unit K. It is different from the embodiment.

  The spatial light modulator 53 is a device that performs pattern adjustment and aberration correction of the laser light L by controlling the wavefront of the light. In this spatial light modulator 53, for example, the laser beam L incident by a parallel aligned nematic liquid crystal layer liquid crystal is phase-modulated and reflected, and only the phase of the light is modulated while maintaining the light intensity and the polarization direction. The liquid crystal state (phase modulation amount) is controlled for each pixel by a signal from a controller (not shown).

In the present embodiment, the spatial light modulator 53 is reflected between the lenses 5 and 6, for example. Two lenses 54 and 55 are further arranged on the rear side of the lenses 5 and 6. The laser light L emitted from the head 4 a of the optical fiber 4 is reflected by the spatial light modulator 53 between the lenses 5 and 6, converted into parallel light by the lens 54, and then directed toward the light emitting envelope 11 by the lens 55. Condensate. The laser light L that has undergone phase modulation by the spatial light modulator 53 has, for example, three condensing positions Fa in a direction orthogonal to the optical axis LA (in-plane direction of the cross section of the laser light L in a direction perpendicular to the optical axis LA). , Fb, Fc. Therefore, the condensing region of the laser light L can be expanded in the direction orthogonal to the optical axis LA by these condensing positions Fa to Fc, and the light emitting region of the laser support light can be expanded, so that the laser unit 2 can be increased in output. The illuminance of the laser support light can be sufficiently secured.
[Fifth Embodiment]

  FIG. 8 is a schematic view showing a light source device according to the fifth embodiment of the present invention. As shown in the figure, the light source device 61 according to the fifth embodiment replaces the condensing position forming unit 22 with the condensing shape of the condensing region of the laser light L in the in-plane direction intersecting the optical axis LA. It differs from 1st Embodiment by having the condensing shape adjustment part 62 extended as the condensing expansion part K. FIG.

  More specifically, the condensing shape adjusting unit 62 is configured by a cylindrical lens 63. The cylindrical lens 63 is disposed between the lenses 5 and 6, for example. The cylindrical lens 63 changes the incident laser beam L only in one axial direction, and the condensing shape of the laser beam L is perpendicular to the optical axis LA (the surface of the cross section of the laser beam L in the direction perpendicular to the optical axis LA). (Inward direction) is changed linearly. Thereby, the laser beam L has the first condensing position Fa and the second condensing position Fb in the direction of the optical axis LA, and when viewed from the front side as shown in FIG. Is focused at the first condensing position Fa and extends in the direction perpendicular to the optical axis LA at the second condensing position Fb, as viewed from the side as shown in FIG. 8B. The first light condensing position Fa extends in a direction orthogonal to the optical axis LA and is focused at the second light condensing position Fb.

Even in such a light source device 61, the condensing region of the laser light L can be sufficiently expanded by extending the condensing shape, and the light emitting region of the laser support light can be expanded. The illuminance of the laser support light can be sufficiently secured. In the present embodiment, one of the first condensing position Fa and the second condensing position Fb of the laser light L may be disposed in the light emitting envelope 11, and the first condensing position Fa Both the light position Fa and the second light collection position Fb may be disposed in the light emitting envelope 11.
[Sixth Embodiment]

  FIG. 9 is a diagram schematically illustrating a light source device according to the sixth embodiment of the present invention. As shown in the drawing, the light source device 71 according to the sixth embodiment is the first in that it has a diffractive optical element 75 that is a light modulation element as a condensing shape adjusting unit 73 and a condensing position forming unit 74. It is different from the embodiment.

  More specifically, the diffractive optical element 75 is disposed between the lenses 5 and 6, for example. The diffractive optical element 75 functions as a condensing shape adjusting unit 73 that changes the incident laser light L only in one axial direction according to the diffraction pattern, and as shown in FIG. The condensing shape is changed linearly in a direction orthogonal to the optical axis LA (in-plane direction of the cross section of the laser light L in a direction perpendicular to the optical axis LA). As a result, the laser light L extends in the direction orthogonal to the optical axis LA at the condensing position Fa, and the condensing region of the laser light L can be sufficiently expanded, so that the illuminance of the laser supporting light can be sufficiently secured.

  Further, the diffractive optical element 75 functions as a condensing position forming unit 74 by changing the diffraction pattern, and for example, condensing positions Fa, Fb, Fc of the laser light L are formed in a direction orthogonal to the optical axis LA. . Therefore, the condensing region of the laser light L can be expanded in the direction orthogonal to the optical axis LA by these condensing positions Fa to Fc, and the illuminance of the laser supporting light can be sufficiently secured without increasing the output of the laser unit 2. . 9A and 9B, in order to make the condensing position of the laser light L farther from the laser unit 2 side, the lenses 54 and 55 shown in FIG. The lens group may be arranged on the rear stage side of the lens 6.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the change in the thickness of the condensing position forming portion (optical path length adjusting plate) is formed by the stepped portion between the flat plate portions, but the flat plate portions may be connected by a gentle surface. However, it may have an inclined surface that gradually changes the thickness. In addition, the light emission region M of the laser support light is not only formed by a plurality of independent condensing positions of the laser light L, but is formed by arranging a large number of condensing positions substantially continuously. May be.

  DESCRIPTION OF SYMBOLS 1,31,41,51,61,71 ... Light source device, 2 ... Laser part, 3 ... Optical system, 7 ... Light source, 11 ... Luminous envelope, 22, 42, 52, 74 ... Condensing position formation part, 23 , 23A to 23C, 33, 34 ... optical path length adjusting plate, 24 ... actuator (driving unit), 43 ... lens array, 53 ... spatial light modulator (light modulating element), 62, 73 ... condensing shape adjusting unit, 75 ... Diffraction optical element (light modulation element), Fa to Fd ... Condensing position, G ... Luminescent gas, K ... Condensing extension, L ... Laser light, LA ... Optical axis, S ... Internal space.

Claims (12)

A laser unit that emits laser light;
A light source including a light emitting envelope in which a luminescent gas is sealed in an internal space;
An optical system for condensing the laser light in the light emitting envelope;
A light source device, comprising: a condensing extension unit that extends a condensing region of the laser light by the optical system in an optical axis direction of the laser light or an in-plane direction intersecting the optical axis direction.   The light source device according to claim 1, wherein the condensing extension unit includes a condensing position forming unit that forms a plurality of condensing positions in the condensing region of the laser light.   The condensing position forming unit is configured by an optical path length adjusting plate that changes an optical path length of a part of the laser light in an optical axis direction of the laser light with respect to a condensing position of another part. The light source device according to claim 2. The condensing position forming unit includes a plurality of the optical path length adjusting plates,
4. The light source device according to claim 3, wherein the plurality of optical path length adjusting plates are arranged in an optical axis direction of the laser light so that advance positions with respect to the laser light are different from each other.   5. The light source device according to claim 3, further comprising a drive unit that drives the optical path length adjusting plate with respect to the laser light.   The light source device according to claim 2, wherein the condensing position forming unit is configured by an optical path length adjusting plate that changes an optical path length of the laser light around an axis in the optical axis direction.   The light source device according to claim 2, wherein the condensing position forming unit includes an optical path length adjusting plate that changes an optical path length of the laser light in a radial direction of the optical axis.   The light source device according to claim 2, wherein the condensing position forming unit is configured by a lens array.   The light source device according to claim 2, wherein the condensing position forming unit is configured by a light modulation element.   The condensing extension unit includes a condensing shape adjusting unit that extends a condensing shape in the condensing region of the laser light in an in-plane direction intersecting the optical axis direction. 1. The light source device according to 1.   The light source device according to claim 10, wherein the condensing shape adjusting unit is configured by a cylindrical lens.   The light source device according to claim 10, wherein the condensing shape adjusting unit is configured by a light modulation element.

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