JP2009200284A - Laser light source device, image display device, and monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser light source device capable of achieving high power, and to provide an image display device and a monitoring device. <P>SOLUTION: The laser light source device includes a light source emitting a fundamental wavelength light, a wavelength conversion element 16 for converting at least part of the fundamental wavelength light into a laser beam having a predetermined conversion wavelength, a reflection part 18 provided at an emission edge face 16b of the wavelength conversion element 16 to make a light having a predetermined conversion wavelength penetrate and to make the fundamental wavelength light reflect, and an optical path adjusting element 13 that makes the fundamental wavelength light emitted from the light source reflect toward the wavelength conversion element 16 and adjusts an optical path of the fundamental wavelength light reflected at the reflective part 18 so as to be returned to the light source. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laser light source device, an image display device, and a monitor device.

  Conventionally, high-pressure mercury lamps have been frequently used as illumination light sources for optical devices such as projectors, but there are problems such as color reproducibility, difficulty in instantaneous lighting, and short life. Therefore, in this field, development of a laser light source device has been advanced in order to solve these problems. In particular, a laser light source device having an external resonator structure can enhance the light of a specific wavelength by using an external resonator and obtain a high output. Further, for example, after oscillating light having a fundamental wavelength such as infrared laser light, infrared laser light is used by using a wavelength conversion element such as a second harmonic generator (hereinafter abbreviated as SHG). Is converted to visible light having a half wavelength (see, for example, Patent Document 1).

In the second harmonic generation device described in Patent Document 1, a convex surface having a curvature is formed on the exit end face of a domain inversion structure made of a nonlinear optical material, and a mirror structure is provided on the convex surface. By tilting the nonlinear optical material, the resonance length of the light traveling through the nonlinear optical material can be changed, and second harmonic light of green light or blue light can be generated.
JP-A-6-132595

However, the second harmonic generation device described in Patent Document 1 requires processing to form a convex surface having a curvature on the exit end face of the nonlinear optical material, which increases the cost. Further, since a convex surface having a curvature in one direction has an allowable angle deviation of only one axis, it is necessary to accurately dispose a nonlinear optical material for the other one angle axis. This leads to an increase in assembly man-hours.
In addition, the nonlinear optical crystal may control wavelength matching with temperature. In this case, the wavelength conversion element is arranged on a heat spreader provided with a heater designed to have a predetermined heat radiation amount. At this time, when the angle adjustment of the nonlinear optical crystal is performed in order to perform the surface alignment between the light source and the mirror structure, the gap between the wavelength conversion element and the heat spreader surface is increased, and the amount of the adhesive filled in the gap is increased. To increase. As a result, the amount of heat released from the heat spreader decreases, and the laser absorption at the time of laser oscillation becomes higher than the matching temperature of the nonlinear optical crystal, and the nonlinear optical crystal falls out of the phase matching condition. Thereby, the intensity | strength of the emitted laser beam will fall.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a laser light source device, an image display device, and a monitor device capable of realizing high output.

In order to achieve the above object, the present invention provides the following means.
The laser light source device of the present invention includes a light source that emits light having a fundamental wavelength, a wavelength conversion element that converts at least a part of the light having the fundamental wavelength into light having a predetermined conversion wavelength, and an emission end face of the wavelength conversion element. A reflection unit that transmits the light of the predetermined conversion wavelength and reflects the light of the fundamental wavelength; reflects the light of the fundamental wavelength emitted from the light source toward the wavelength conversion element; and the reflection unit And an optical path adjusting element that adjusts the optical path of the light having the fundamental wavelength reflected in step 1 to return to the light source.

In the laser light source device according to the present invention, light having a fundamental wavelength emitted from the light source enters the wavelength conversion element via the optical path adjustment element. The light that has been converted to the predetermined conversion wavelength among the light incident on the wavelength conversion element is transmitted through the reflecting portion provided on the emission end face of the wavelength conversion element, and the fundamental wavelength light that has not been converted to the predetermined conversion wavelength. Is reflected at the reflecting portion. The fundamental wavelength light reflected by the reflecting portion is incident on the wavelength conversion element again. Then, the optical path of the light having the fundamental wavelength that has not been converted to the predetermined conversion wavelength by passing through the wavelength conversion element is adjusted by the optical path adjustment element.
Here, by adjusting the optical path adjusting element, it becomes possible to accurately return the light having the fundamental wavelength reflected by the reflecting portion to the light source. That is, even when the angle between the light source and the reflecting portion is not resonable, the light emitted from the light source can be resonated between the light source and the reflecting portion by adjusting the angle of the optical path adjusting element. Become. Therefore, since the arrangement accuracy of the wavelength conversion element is not required, it is possible to emit a high-power laser beam by simple assembly.

  Further, even when the temperature of the wavelength conversion element is controlled, the light source and the reflecting portion can be aligned without moving the wavelength conversion element. Thereby, since the gap amount between the wavelength conversion element and the heat spreader does not change from the design value, it is possible to perform temperature control in which a predetermined heat radiation amount is ensured. Therefore, since the wavelength conversion element can be kept at a predetermined temperature, the light use efficiency in the wavelength conversion element can be improved.

  In the laser light source device of the present invention, it is preferable that the optical path adjusting element transmits the light having the predetermined conversion wavelength and emits the light in a direction different from the light source.

  In the laser light source device according to the present invention, the optical path adjusting element transmits light having a predetermined conversion wavelength and emits it in a direction different from the light source. Thereby, the light reflected by the reflection part and converted to the predetermined conversion wavelength by passing through the wavelength conversion element again can be extracted from the optical path between the light source and the reflection part. Therefore, it is possible to improve the utilization efficiency of the light emitted from the light source.

  Moreover, it is preferable that the laser light source apparatus of this invention is provided with the angle adjustment mechanism which adjusts the angle of the said optical path adjustment element.

In the laser light source device according to the present invention, the optical path of the light reflected by the reflecting portion and incident on the optical path adjusting element is adjusted by the angle adjusting mechanism. As a result, the light reflected by the reflecting portion can be accurately incident on the light source.
If the angle adjustment mechanism is not provided, after adjusting the optical path adjustment element, for example, it is necessary to fix the optical path adjustment element with an adhesive. Also changes over time. However, in the present invention, since it is different from fixing with an adhesive or the like, the positional deviation of the optical path adjusting element due to secular change is reduced, and it is possible to suppress a decrease in output intensity.

  The laser light source device of the present invention further includes a holding member that holds the optical path adjusting element in the groove, and the angle adjusting mechanism is provided in the groove and fixes the optical path adjusting element, and the optical path adjusting element A first screw portion and a second screw portion that are provided in contact with the emission end surface of the holding member on the emission end surface side of the emission end surface, and advance and retreat in a direction from the emission end surface toward the incident end surface of the optical path adjustment element, and the optical path adjustment It is preferable to include an elastic member provided between the incident end face of the element and the groove.

In the laser light source device according to the present invention, it is possible to adjust the two angle axes of the optical path adjusting element held by the holding member by advancing and retracting the first and second screw portions provided on the holding member. As described above, the optical path of the light reflected at the reflecting portion is adjusted by the first and second screw portions, so that the surface of the mirror in the light source and the reflecting surface of the reflecting portion can be easily configured with high accuracy. It becomes possible to align well.
Furthermore, by providing an elastic member between the incident end face of the optical path adjusting element and the groove, the exit end face of the optical path adjusting element can be pressed against the first and second screw portions. Thereby, it can suppress that a clearance gap produces between a 1st, 2nd screw part and an optical path adjustment element. Therefore, the contact between the optical path adjusting element and the first and second screw portions can be kept good.

  The laser light source device of the present invention includes a wavelength selection unit that is disposed on an optical path between the light source and the wavelength conversion element and transmits light having a predetermined selection wavelength among light emitted from the light source. preferable.

  In the laser light source device according to the present invention, the light emitted from the light source passes through the wavelength selection unit, and the light having a predetermined selection wavelength is transmitted. As a result, the spectrum of the oscillation wavelength of the light that travels back and forth between the light source and the reflecting portion is limited, so that light with a desired wavelength can be stably emitted.

  In the laser light source device of the present invention, it is preferable that the wavelength selection unit is formed on the incident end face of the wavelength conversion element.

  In the laser light source device according to the present invention, the wavelength selection unit is formed on the incident end face of the wavelength conversion element. Thereby, compared with the case where the wavelength conversion element and the wavelength selection unit are provided separately, the interface between the optical member through which the light emitted from the light source passes and the air can be reduced, so that the loss of light amount is reduced. It becomes possible to suppress. Therefore, it becomes possible to emit a high-power laser beam.

  An image display device according to the present invention includes the laser light source device described above and an image forming device that displays an image of a desired size on a display surface using light from the laser light source device. .

  In the image display device according to the present invention, the laser light emitted from the laser light source device enters the image forming apparatus. Then, an image formed by the image forming apparatus is displayed on the display surface. At this time, since the light emitted from the laser light source device emits a high-power laser beam as described above, a bright and clear image can be displayed.

  A monitor device according to the present invention includes the laser light source device described above and an imaging unit that captures an image of a subject using laser light emitted from the laser light source device.

  In the monitor device according to the present invention, the laser light emitted from the laser light source device irradiates the subject, and the subject is imaged by the imaging means. At this time, as described above, in order to emit high-power laser light, the subject is irradiated with bright light. Therefore, the subject can be clearly imaged by the imaging means.

  Hereinafter, embodiments of a laser light source device, an image display device, 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]
As shown in FIGS. 1 and 2, the laser light source device 1 includes a base 11, a semiconductor laser element (light source) 12, a dichroic mirror (optical path adjustment element) 13, a wavelength conversion element 16, and an angle adjustment mechanism 20. And.
Here, the emission direction of the laser light emitted from the semiconductor laser element 12 is defined as the Z axis, the arrangement direction of the emitters 14 described later is defined as the Y axis, and the axis orthogonal to the emission direction and the alignment direction is defined as the X axis.

As shown in FIG. 2, the semiconductor laser element 12 is a surface-emitting laser diode that emits, for example, infrared laser light (fundamental wavelength light) having a wavelength of 1065 nm from the emission end face 12a. A plurality of emitters (light emitting portions) 14 are respectively formed. Specifically, the semiconductor laser element 12 has a plurality of emitters 14 in the Y-axis direction.
Further, as shown in the enlarged view of FIG. 2, the emitter 14 has a configuration in which an active layer 12c is laminated on a DBR (Distributed Bragg Reflector) layer 12b.

As shown in FIG. 2, a dichroic mirror 13 is disposed on the optical path of the laser light emitted from the semiconductor laser element 12. The dichroic mirror 13 is arranged so that the laser light emitted from the semiconductor laser element 12 enters the reflecting surface (incident end surface) 13a at an angle of 45 °. Thereby, the optical path of the laser light emitted from the semiconductor laser element 12 is converted by 90 ° and emitted.
As shown in FIG. 1, the dichroic mirror 13 is held by first and second holding portions (holding members) 31 and 32 having groove portions 31a and 32a. The first and second holding portions 31 and 32 are provided on the end side in the Y axis direction of the dichroic mirror 13 and open in a direction of an angle of 45 ° on the XZ plane. And the edge part of the dichroic mirror 13 is arrange | positioned in the groove parts 31a and 32a, providing the dichroic mirror 13 and the clearance gap 33. FIG.

As shown in FIG. 1, the wavelength conversion element 16 is disposed on the optical path of the laser light emitted from the dichroic mirror 13. The wavelength conversion element 16 is arranged so that all the laser beams emitted from the plurality of emitters 14 are incident on the incident end face 16a.
As the wavelength conversion element 16, PPLN (Periodically Poled Lithium Niobate), which is a nonlinear optical element, is used, and functions as an SHG element that converts incident light into almost a half wavelength and generates a second harmonic.
As shown in FIG. 1, a part of the light emitted from the semiconductor laser element 12 passes through the wavelength conversion element 16, so that almost half (532.5 nm) of green laser light ( Light of a predetermined conversion wavelength).

  The wavelength conversion element 16 is bonded and fixed to an upper surface 26a of a temperature adjustment substrate (a copper plate in this embodiment) that functions as a heat spreader. The temperature adjustment substrate 26 is provided with a thermistor (not shown) for adjusting the temperature of the wavelength conversion element 16 and a heater (not shown). Since the internal refractive index of the wavelength conversion element 16 changes as the temperature changes, the temperature of the wavelength conversion element 16 is detected by a thermistor, and the wavelength conversion element 16 is detected by a heater based on the detected temperature of the wavelength conversion element 16. 16 is heated. In other words, the wavelength adjusting element 26 is expanded by adjusting the wavelength conversion element 16 to an appropriate temperature, and wavelength matching is performed. As a result, the laser light emitted from the semiconductor laser element 12 can be efficiently converted into a harmonic laser light having a predetermined conversion wavelength.

In addition, a reflection film (reflection part) 18 that functions as a resonator mirror is formed on the emission end face 16 b of the wavelength conversion element 16. The reflective film 18 has a function of selectively transmitting the light converted into the half wavelength by the wavelength conversion element 16 and reflecting other light. That is, the light that has not been converted into the half wavelength by the wavelength conversion element 16 is returned to the semiconductor laser element 12 by the reflection film 18. In the present embodiment, as shown in FIG. 2, the reflection film 18 is light (infrared light: basic light) that has not been converted into a predetermined conversion wavelength by the wavelength conversion element 16 among the light emitted from the wavelength conversion element 16. Light of a wavelength) is selectively reflected with high efficiency of about 80% or more, and light converted to a predetermined conversion wavelength is transmitted about 80% or more. That is, the laser light emitted from the semiconductor laser element 12 resonates between the DBR layer 12b of the semiconductor laser element 12 and the reflective film 18, thereby amplifying the laser light having a predetermined conversion wavelength.
Further, the laser light emitted from the semiconductor laser element 12 is condensed by the thermal lens effect. The reflective film 18 is disposed so as to be positioned at the beam waist portion of the condensed laser light. Thereby, the conversion efficiency in the wavelength conversion element 16 can be improved.

  Further, the dichroic mirror 13 adjusts the optical path of the laser light (fundamental wavelength light) reflected by the reflective film 18. Specifically, the laser light reflected by the reflective film 18 passes through the wavelength conversion element 16 again to transmit the laser light converted into light having a predetermined conversion wavelength, and is different from the semiconductor laser element 12. Inject in the direction. On the other hand, the laser light that has not been converted to the predetermined conversion wavelength is returned to the DBR layer 12b of the semiconductor laser element 12.

As shown in FIG. 1, the angle adjustment mechanism 20 includes a fixed portion 21, a first screw portion 22, a second screw portion 23, and springs (elastic members) 24 and 25. The angle is adjusted to adjust the optical path through which the laser light reflected from the reflective film 18 and emitted from the wavelength conversion element 16 is emitted toward the semiconductor laser element 12.
As shown in FIG. 3, the fixing part 21 is provided in the groove part 32 a of the second holding part 32. Specifically, the fixed portion 21 is in contact with the emission end face 13 b of the dichroic mirror 13. By this fixing portion 21, the dichroic mirror 13 can be stably held. Further, another fixing portion 27 is provided in the groove portion 32 a, and this other fixing portion 27 is in contact with the bottom surface 13 c of the dichroic mirror 13.

As shown in FIG. 1, the first screw portion 22 is provided in the first holding portion 31 on the emission end face 13 b side of the dichroic mirror 13 and is in contact with the corner portion 13 d of the dichroic mirror 13. The second screw 23 is provided on the second holding portion 32 on the emission end face 13b side of the dichroic mirror 13 and is in contact with the corner 13d of the dichroic mirror 13 and the corner 13e. . That is, the first and second screw portions 22 and 23 are disposed at diagonal positions on the exit end face 13b of the dichroic mirror 13, as shown in FIGS.
Then, as shown in FIG. 1, the first and second screw portions 22 and 23 are rotated, the first screw portion 22 is advanced and retracted in the longitudinal direction (arrow A direction), and the second screw portion 23 is moved in the longitudinal direction (arrow). B direction). And the length of the 1st, 2nd screw parts 22 and 23 which protrude in the groove parts 31a and 32a is changed. As a result, the angle of the dichroic mirror 13 about the axis P1 in the width direction and the axis P2 in the length direction changes. By adjusting the biaxial angle of the dichroic mirror 13 in this way, the optical path of the laser beam reflected by the dichroic mirror 13 is adjusted and made incident on the DBR layer 12b of the corresponding semiconductor laser element 12.

  Further, as shown in FIG. 3, springs 24 and 25 are provided in the gap 33 between the incident end face 13a of the dichroic mirror 13 and the grooves 31a and 32a, respectively. Since the springs 24 and 25 are urged in the direction from the incident end face 13a of the dichroic mirror 13 toward the exit end face 13b, the dichroic mirror 13 is urged by the urging forces of the springs 24 and 25 into the first and second screw portions 22,. 23.

As described above, in the laser light source device 1 according to the present embodiment, the optical path of the laser light having the fundamental wavelength reflected by the reflective film 18 is adjusted by adjusting the angle of the dichroic mirror 13 about the axes P1 and P2. Can be accurately returned to the DBR layer 12b of the semiconductor laser element 12. That is, even when the semiconductor laser element 12 and the reflection film 18 are not at an angle capable of resonating, by adjusting the angle of the dichroic mirror 13, the incident position of the laser beam and the DBR layer 12 b of the semiconductor laser element 12 are adjusted. Alignment is performed. As a result, the laser light emitted from the semiconductor laser element 12 can be resonated between the DBR layer 12 b of the semiconductor laser element 12 and the reflection film 18. Therefore, since the arrangement accuracy of the wavelength conversion element 16 is not required, it is possible to emit a high-power laser beam by simple assembly.
Even when the temperature of the wavelength conversion element 16 is controlled, the DBR layer 12b of the semiconductor laser element 12 and the reflection film 18 can be aligned by adjusting the angle of the dichroic mirror 13 without moving the wavelength conversion element 16. . Thereby, since the gap amount between the wavelength conversion element 16 and the heat spreader does not change from the design value, it is possible to perform temperature control in which a predetermined heat radiation amount is ensured. Therefore, since the wavelength conversion element 16 can be kept at a predetermined temperature, the utilization efficiency of laser light in the wavelength conversion element 16 can be improved.
That is, the laser light source device 1 of the present embodiment can achieve high output.

The dichroic mirror 13 also has a characteristic of transmitting laser light having a predetermined conversion wavelength. As a result, the laser beam reflected by the reflection film 18 and passing through the wavelength conversion element 16 again is extracted from the optical path between the DBR layer 12 b of the semiconductor laser element 12 and the reflection film 18. It becomes possible. Therefore, the utilization efficiency of the laser light emitted from the semiconductor laser element 12 can be improved.
Further, by adjusting the angle of the dichroic mirror 13 by the angle adjusting mechanism 20, the laser light reflected by the reflective film 18 can be accurately incident on the DBR layer 12 b of the semiconductor laser element 12. In addition, since the angle of the dichroic mirror 13 is adjusted by moving the first and second screw portions 22 and 23 back and forth, the laser beam reflected by the reflective film 18 can be a semiconductor laser with a simple configuration and high accuracy. The light can enter the DBR layer 12b of the element 12.
Further, by providing the springs 24 and 25, the dichroic mirror 13 can be pressed against the first and second screw portions 22 and 23. Thereby, it can suppress that a clearance gap produces between the 1st, 2nd screw parts 22 and 23 and the dichroic mirror 13. FIG. Therefore, the contact between the dichroic mirror 13 and the first and second screw portions 22 and 23 can be kept good, and the angle of the dichroic mirror 13 can be adjusted with high accuracy.

  The reflective film 18 is disposed so as to be positioned at the beam waist portion of the laser beam. Here, since the conversion efficiency in the wavelength conversion element 16 is proportional to the square of the energy density, the laser energy density in the wavelength conversion element 16 is increased and the conversion efficiency is improved. Further, compared to the case where the reflection film 18 is not provided and the reflection mirror is provided separately from the wavelength conversion element 16, in this embodiment, since there is no interface between the reflection film 18 and the air, the interface of the light of the fundamental wavelength is provided. Loss of light quantity due to reflection is reduced. Therefore, it becomes possible to emit a higher-power laser beam.

The dichroic mirror 13 transmits the laser light converted into light of a predetermined conversion wavelength by passing again through the wavelength conversion element 16 out of the laser light reflected by the reflection film 18 of the wavelength conversion element 16. However, this function is not necessarily required. In other words, a configuration may be used in which a laser beam converted into a predetermined conversion wavelength is taken out only by the reflection film 18 of the wavelength conversion element 16 using a reflection mirror having only a characteristic of reflecting instead of the dichroic mirror 13.
Further, the other fixing portion 27 is not necessarily provided, but by providing the other fixing portion 27, the dichroic mirror 13 can be held more stably.
In addition, the angle adjustment mechanism 20 includes the fixing portion 21, the first screw portion 22, the second screw portion 23, and the springs 24 and 25, but the configuration of the angle adjustment mechanism 20 is not limited thereto. Instead, any mechanism that adjusts the incident angle of the laser light reflected by the reflective film 18 and incident on the dichroic mirror 13 may be used. Further, the angle adjusting mechanism 20 may not be provided, and the angle may be fixed after adjusting the angle of the dichroic mirror 13 by an adjusting mechanism (not shown) provided in the manufacturing apparatus.
Further, although the first and second screw portions 22 and 23 are in direct contact with the dichroic mirror 13, the first and second screw portions 22 and 23 are framed in a configuration in which the dichroic mirror 13 is held by the frame. The frame may be brought into contact with the body and pressed in the direction of arrow A and arrow B. In this configuration, it is possible to suppress damage to the dichroic mirror 13 as compared with the case where the first and second screw portions 22 and 23 are in direct contact with the dichroic mirror 13.
Moreover, although the 1st holding | maintenance part 31 and the 2nd holding | maintenance part 32 were provided separately, you may be comprised integrally. Moreover, although it was set as the structure provided with the several emitter 14, the structure provided with the semiconductor laser element 12 provided with one emitter may be sufficient.

[First Modification of First Embodiment]
In the first embodiment shown in FIG. 1, the angle adjustment mechanism 20 is used to adjust the angle of the dichroic mirror 13 so that the laser light reflected by the reflective film 18 is accurately incident on the DBR layer 12 b of the semiconductor laser element 12. However, the laser light source device 40 that does not include the angle adjustment mechanism 20 may be used.
As shown in FIG. 5, the dichroic mirror 13 of the laser light source device 40 first adjusts the angles of the width direction axis P <b> 1 and the length direction axis P <b> 2 of the dichroic mirror 13 by an adjustment mechanism (not shown). Thereafter, at least a part of the gap 33 between the first and second holding portions 31 and 32 and the dichroic mirror 13 is filled with an adhesive 41 (fixing member), whereby the dichroic mirror 13 is filled with the first and second holding portions 31. , 32.
Also in this configuration, by adjusting the angle of the dichroic mirror 13, the laser light reflected by the reflective film 18 can be accurately incident on the DBR layer 12 b of the semiconductor laser element 12. This makes it possible to emit a high-power laser beam.

[Modification 2 of the first embodiment]
In the second modification of the first embodiment, as illustrated in FIG. 6, a laser light source device including a cover member 46 that covers the groove portions 31 a and 32 b may be used. In FIG. 6, only a portion different in configuration from the first embodiment is shown, and the first and second holding portions 31 and 32 have the same configuration, and therefore the second holding portion 32 will be described as an example. .
As shown in FIG. 6, the cover member 46 is in contact with the upper surface 13 f of the dichroic mirror 13 and the end surfaces 32 b and 32 c of the second holding portion 32. Specifically, the cover member 46 is in contact with an end surface 32 b substantially parallel to the emission end surface 12 a of the semiconductor laser element 12 and an end surface 32 c substantially parallel to the upper surface 13 f of the dichroic mirror 13. The cover member 46 is fixed to the end surface 32 b of the second holding portion 32 by the first screw portion 47, and the cover member 46 is fixed to the end surface 32 c of the second holding portion 32 by the second screw portion 48. Yes. Further, the cover member 46 has an elastic force and is biased from the upper surface 13 f of the dichroic mirror 13 toward the other fixing portion 27. A similar cover member 46 is also provided in the first holding portion 31.
As described above, by providing the cover member 46, it is possible to suppress the positional deviation of the dichroic mirror 13 in the width direction, and thus it is possible to adjust the angle of the dichroic mirror 13 with higher accuracy.
The arrangement of the cover member 46 is not limited to this, and may be a cover member that contacts the side surface 13g of the dichroic mirror 13 and the side surface 32d of the second holding portion 32, for example. Thereby, the position shift of the length direction of the dichroic mirror 13 can be suppressed. Moreover, the structure provided with both the cover member 46 which suppresses the position shift of the width direction, and the cover member which suppresses the position shift of the length direction may be sufficient.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. Note that, in the drawings of the embodiments described below, portions having the same configuration as those of the laser light source device 1 according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
The laser light source device 60 according to the present embodiment is different from the first embodiment in that a BPF 61 is provided. Other configurations are the same as those of the first embodiment.

A BPF (Band-Pass Filter, wavelength selection unit) 61 is arranged on the optical path between the dichroic mirror 13 and the wavelength conversion element 16 as shown in FIG. The BPF 61 has a characteristic of transmitting a laser beam having a predetermined selection wavelength among the laser beams reflected by the dichroic mirror 13.
Further, the BPF 61 is disposed to be inclined with respect to a plane perpendicular to the central axis O of the laser light reflected by the dichroic mirror 13. As a result, the BPF 61 prevents laser light other than the predetermined selection wavelength from returning to the semiconductor laser element 12.

As described above, in the laser light source device 60 according to the present embodiment, the laser light emitted from the semiconductor laser element 12 passes through the BPF 61 to have a necessary bandwidth. Thus, since the BPF 61 is limited in the spectrum of the oscillation wavelength of the laser light that reciprocates between the semiconductor laser element 12 and the reflection film 18, the green laser light is stably output by the BPF 61. ing.
Further, by providing the BPF 61 separately from the wavelength conversion element 16 instead of integrally forming the BPF 61, it becomes easy to manufacture the BPF 61 that transmits laser light having a desired selection wavelength.
Note that the BPF 61 does not necessarily have to be inclined.
Further, although the BPF 61 is disposed on the optical path between the dichroic mirror 13 and the wavelength conversion element 16, it may be provided on the optical path between the semiconductor laser element 12 and the dichroic mirror 13.

[Third Embodiment]
Next, a third embodiment according to the present invention will be described with reference to FIG.
The laser light source device 70 according to the present embodiment is different from the first embodiment in that the wavelength selection film 71 is formed on the incident end face 16a of the wavelength conversion element 16. Other configurations are the same as those of the first embodiment.

  As shown in FIG. 8, the incident end face 16a of the wavelength conversion element 16 is inclined, and a wavelength selection film (wavelength selection unit) 71 is formed on the inclined surface. In this way, by forming the wavelength selection film 71 by tilting the incident end face 16a of the wavelength conversion element 16, laser light having a predetermined selection wavelength is transmitted. In addition, since the incident end face 16 a of the wavelength conversion element 16 is inclined, laser light other than a predetermined selection wavelength is prevented from returning to the semiconductor laser element 12.

As described above, in the laser light source device 70 according to the present embodiment, since the wavelength selection film 71 is formed on the incident end face 16a of the wavelength conversion element 16, the wavelength conversion element 16 and the wavelength selection unit are provided separately. As compared with the above, the interface between the optical member through which the laser light emitted from the semiconductor laser element 12 passes and the air can be reduced. Accordingly, the loss of the light amount can be suppressed, so that high-power laser light can be emitted.
The incident end face 16a of the wavelength conversion element 16 does not necessarily have to be inclined.

[Fourth Embodiment]
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.
In the present embodiment, a projector including the laser light source devices (including modifications) of the first to third embodiments will be described. FIG. 9 is a schematic configuration diagram of the projector according to the present embodiment.

The projector 100 according to this embodiment includes a red laser light source device 1R, a green laser light source device 1G, and a blue laser light source device 1B that emit red light, green light, and blue light, respectively. Light source devices (including modifications) 40, 60, 70 according to the third embodiment.
The projector 100 emits light from the transmissive liquid crystal light valves (light modulation devices) 104R, 104G, and 104B and the liquid crystal light valves 104R, 104G, and 104B that modulate the color lights emitted from the laser light source devices 1R, 1G, and 1B, respectively. A projection lens (projection means) that magnifies and projects the image formed by the cross dichroic prism (color synthesis means) 106 that synthesizes the synthesized light and guides it to the projection lens 107 and the liquid crystal light valves 104R, 104G, and 104B. 107).

  Further, the projector 100 includes uniform optical systems 102R, 102G, and 102B for uniformizing the illuminance distribution of the laser light emitted from the laser light source devices 1R, 1G, and 1B, and the illuminance distribution is uniformized. The liquid crystal light valves 104R, 104G, and 104B are illuminated with light. In the present embodiment, 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, the laser light source devices 40, 60, and 70 of the first to third embodiments are used as the red laser light source device 1R, the green laser light source device 1G, and the blue laser light source device 1B. Therefore, it is possible to realize a compact, inexpensive projector capable of displaying bright images.

  Although a transmissive liquid crystal light valve is used as the light modulator, a reflective light valve may be used, or a light modulator other than liquid crystal may be used. Examples of such a light valve include a reflective liquid crystal light valve and a digital micromirror device. What is necessary is just to change suitably the structure of a projection optical system according to the kind of used light valve.

[Fifth Embodiment]
Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG.
In the present embodiment, a scanning image display device will be described. FIG. 10 is a schematic configuration diagram of the image display apparatus of the present embodiment.

As shown in FIG. 10, the image display apparatus 200 according to the present embodiment includes the laser light source apparatus 1 according to the first embodiment and a MEMS mirror (scanning) that scans light emitted from the laser light source apparatus 1 toward the screen 210. Means) 202 and a condensing lens 203 that condenses the light emitted from the laser light source device 1 on the MEMS mirror 202. The light emitted from the laser light source device 1 is scanned in the horizontal and vertical directions on the screen 210 by driving the MEMS mirror 202. In the case of displaying a color image, for example, a plurality of emitters constituting a laser diode may be constituted by a combination of emitters having red, green, and blue peak wavelengths.
The laser light source devices (including modifications) 40, 60, 70 of the second and third embodiments may be used.

[Sixth Embodiment]
Hereinafter, a configuration example of the monitor device 300 to which the laser light source device 1 of the above embodiment is applied will be described with reference to FIG.
FIG. 11 is a schematic configuration diagram of the monitor device of the present embodiment.
As shown in FIG. 11, the monitor device 300 according to the present embodiment includes a device main body 310 and an optical transmission unit 320. The apparatus main body 310 includes the laser light source apparatus 1 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 1 is installed on the incident side of the light guide 321 on the light transmission side, and the diffusion plate 323 is installed on the emission side. The laser light emitted from the laser light source device 1 is sent 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 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 is sent to a camera 311 as an imaging means provided in the apparatus main body 310 through a light guide 322 on the receiving side. As a result, an image based on the reflected light obtained by irradiating the subject with the laser light emitted from the laser light source device 1 can be captured by the camera 311.

According to the monitor device 300 of the present embodiment, since the laser light source device 1 of the first embodiment is used, a monitor device that is small, inexpensive, and capable of clear imaging can be realized.
The laser light source devices (including modifications) 40, 60, 70 of the second and third embodiments may be used.

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, although a cross dichroic prism is used as the color light combining means, the present invention is not limited to this. As the color light synthesizing means, for example, a dichroic mirror having a cross arrangement to synthesize color light, or a dichroic mirror arranged in parallel to synthesize color light can be used.

1 is a perspective view showing a laser light source device according to a first embodiment of the present invention. It is a perspective view which shows the laser light source device of FIG. It is a top view which shows the laser light source apparatus of FIG. It is a rear view of the laser light source device of FIG. It is a perspective view which shows the modification 1 of the laser light source apparatus which concerns on 1st Embodiment of this invention. It is a perspective view which shows the modification 2 of the laser light source apparatus which concerns on 1st Embodiment of this invention. It is a top view which shows the laser light source device which concerns on 2nd Embodiment of this invention. It is a top view which shows the laser light source apparatus which concerns on 3rd Embodiment of this invention. It is principal part sectional drawing which shows the image display apparatus which concerns on 2nd Embodiment of this invention. It is principal part sectional drawing which shows the image display apparatus which concerns on 3rd Embodiment of this invention. It is principal part sectional drawing which shows the monitor apparatus which concerns on 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,40,60,70 ... Laser light source device, 12 ... Semiconductor laser element (light source), 13 ... Dichroic mirror (optical path adjustment element), 16 ... Wavelength conversion element, 18 ... Reflection film (reflection part), 20 ... Angle adjustment Mechanism: 22 ... 1st screw part, 23 ... 2nd screw part, 31 ... 1st holding part, 32 ... 2nd holding part

Claims (8)

A light source that emits light of a fundamental wavelength;
A wavelength conversion element that converts at least a part of the light of the fundamental wavelength into light of a predetermined conversion wavelength;
A reflection part provided on an emission end face of the wavelength conversion element to transmit the light of the predetermined conversion wavelength and reflect the light of the fundamental wavelength;
And an optical path adjusting element that reflects the light of the fundamental wavelength emitted from the light source toward the wavelength conversion element and adjusts the optical path of the light of the fundamental wavelength reflected by the reflection unit. Laser light source device.   2. The laser light source device according to claim 1, wherein the optical path adjustment element transmits light having the predetermined conversion wavelength and emits the light in a direction different from the light source.   The laser light source device according to claim 1, further comprising an angle adjustment mechanism that adjusts an angle of the optical path adjustment element. A holding member for holding the optical path adjusting element in the groove;
The angle adjusting mechanism is provided in the groove, and a fixing part that fixes the optical path adjusting element;
A first screw portion and a second screw portion which are provided in contact with the emission end surface on the holding member on the emission end surface side of the optical path adjustment element and advance and retreat in a direction from the emission end surface toward the incidence end surface of the optical path adjustment element; ,
The laser light source device according to claim 3, further comprising an elastic member provided between an incident end face of the optical path adjusting element and the groove.   2. The device according to claim 1, further comprising a wavelength selection unit that is disposed on an optical path between the light source and the wavelength conversion element and transmits light having a predetermined selection wavelength among light emitted from the light source. Item 5. The laser light source device according to any one of Items 4 above.   The laser light source device according to claim 5, wherein the wavelength selection unit is formed on an incident end face of the wavelength conversion element. The laser light source device according to any one of claims 1 to 6,
An image display apparatus comprising: an image forming apparatus that displays light of a desired size on a display surface using light from the laser light source device. The laser light source device according to any one of claims 1 to 6,
A monitor device comprising: imaging means for imaging a subject by laser light emitted from the laser light source device.

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