JP2009117574A - Light source apparatus, projector, and monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide light source apparatus that can increase the output of laser beams, can be miniaturized, and made inexpensive, and to provide a projector and a monitoring device. <P>SOLUTION: The optical device 100 includes: a light element 1 where a plurality of emitters 2 arranged in a line emit laser beams; a wavelength conversion element 20 arranged on an optical path of laser beams emitted from the emitters 2; and an external resonator 30 for composing a resonator structure with the light element 1. The optical device 100 further includes: first and second light elements 1A, 1B arranged in parallel; a first mirror M1 and a second mirror M2 arranged between the first and second light elements 1A, 1B and the wavelength conversion element 20; a first prism 50 that reflects laser beams reflected by the first and second mirrors M1, M2 and transmits laser beams that are reflected by the external resonator 30 and wavelength-converted by the wavelength conversion element 20; and an optical member 60 for reflecting the laser beams after the wavelength conversion through the first prism 50 for emitting outside. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

2. Description of the Related Art Conventionally, a light source device using an optical element such as a semiconductor laser chip as a light source is known for the purpose of reducing the size and increasing the output of a projector or the like. As a laser chip of such a light source device, a laser chip in which a plurality of emitters on the light emitting surface are arranged in an array for high output is used.
Some of such light source devices include an optical element such as a wavelength conversion element outside the light emitting element (see, for example, Patent Document 1).
JP 2007-5352 A

  Incidentally, in recent years, while further increasing the output of the light source device is desired, downsizing of the light source device is desired. However, in order to increase the output of the light source device, for example, when a large number of laser chips are used and a wavelength conversion element is provided for each laser chip, the size of the light source device is increased or a plurality of wavelength conversion elements are provided, thereby reducing the cost of the apparatus. The problem of becoming higher will occur.

  The present invention has been made in view of such circumstances, and provides a light source device, a projector, and a monitor device that can achieve high output of laser light and can be reduced in size and cost. It is aimed.

The present invention employs the following configuration in order to solve the above problems.
That is, the light source device of the present invention includes an optical element that emits laser light from a plurality of emitters arranged in a line, a wavelength conversion element that is disposed on an optical path of laser light emitted from the emitter, and the light And an external resonator constituting a resonator structure between the first optical element and the second optical element arranged in parallel, and emitted from the first optical element. A first mirror disposed between the first optical element and the wavelength conversion element in the optical path of the laser light and reflecting the first laser light emitted from the first optical element; and the second optical element. A second mirror disposed between the second optical element and the wavelength conversion element in the optical path of the emitted laser light, reflecting the second laser light emitted from the second optical element, and the second mirror; The first laser beam reflected by one mirror The first laser beam reflected by the second mirror and the second laser beam reflected by the second mirror, and reflected by the external resonator and wavelength-converted by the wavelength conversion element, and the second laser beam. A first prism that transmits laser light, and an optical member that reflects and emits the first laser light and the second laser light after wavelength conversion transmitted through the first prism to the outside. Features.

  According to the optical device of the present invention, the laser light emitted from the emitters of the two optical elements can pass through the single wavelength conversion element, so that the cost and size of the device can be reduced. Moreover, since the laser light wavelength-converted when passing through the wavelength conversion element again can be taken out as the output of the light source device, high efficiency can be realized. Further, since the laser beams emitted from the two optical elements can be synthesized, high output light can be obtained.

In the light source device, the first optical element and the second optical element are preferably mounted on the same plane.
According to this configuration, alignment with respect to the wavelength conversion element, the external resonator, and the like becomes easy, and the assemblability of the optical device can be improved.

In the light source device, it is preferable that the first optical element and the second optical element are arranged in a state in which the emitters are displaced from each other in the arrangement direction of the emitters.
According to this configuration, wavelength interference and thermal interference between the laser beams in the emitters of the first optical element and the second optical element, and in the wavelength conversion element and in the external resonator are prevented when laser light is emitted. it can. Therefore, a highly efficient and high quality light source device can be realized.

In the light source device, the apex angle of the first prism is preferably set to 90 °.
According to this configuration, since the first prism whose apex angle is set to 90 ° is provided, for example, light reflected by the first mirror and the second mirror is incident on two side surfaces forming the apex angle of the prism. Thus, the laser light of the light source device can be easily incident on the condenser lens installed outside the device. In addition, the manufacture of the first prism is facilitated, and the optical axes of the first and second mirrors and the first prism can be adjusted or their assemblability can be improved.

Or in the said light source device, the vertex angle of the said prism may be set to the acute angle.
According to this configuration, for example, by adjusting the positions of the first and second mirrors so that the laser light from the emitter is incident on the apex angle upper side, the interval between the laser light emitted from the light source device is further narrowed. be able to. Also, for example, even when the width of the wavelength conversion element is reduced, the laser light is reliably incident on one wavelength conversion element by reducing the interval between the laser beams emitted from the first and second optical elements. Can be made.

In the light source device, the optical member includes a second prism that takes out laser light reflected by the external resonator and wavelength-converted by the wavelength conversion element in a predetermined direction. The angle is preferably set to 90 °.
According to this configuration, among the laser beams emitted from the first and second optical elements, the light reflected by the external resonator and wavelength-converted by the wavelength conversion element can be emitted to the outside in a substantially parallel state.

In the light source device, it is preferable that at least one of the first optical element and the second optical element includes a plurality of emitter rows in which the emitters are arranged in a line.
According to this configuration, the density of laser light incident on the wavelength conversion element from each optical element is increased, and laser light can be obtained with high output.

In the light source device, it is preferable that the first and second mirrors are arranged so that the optical path lengths from the first optical element and the second optical element to the wavelength conversion element are equal.
According to this configuration, alignment adjustment in the optical element, the wavelength conversion element, or the external resonator can be facilitated.

  A projector according to the present invention includes the light source device, a light modulation element that modulates laser light emitted from the light source device according to image information, a projection device that projects an image formed by the light modulation element, It is characterized by providing.

  According to the projector of the present invention, as described above, the projector is provided with the light source device that is small in size and low in cost and obtains high output. Therefore, a small projector capable of projecting a high-definition image can be provided at low cost. .

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

  The monitor device irradiates the subject with the laser light emitted from the light source device, and images the subject using an imaging unit. According to the present invention, as described above, since the light source device having a small size, a low cost, and a high output is provided, the subject is irradiated with bright light having no luminance unevenness. Therefore, it is possible to obtain a small monitor device capable of clearly capturing an image of the subject by the image capturing unit at a low cost.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In the following drawings, the scale is appropriately changed for each layer and each member so that each layer and each member can be recognized on the drawing.

(Light source device)
FIG. 1 shows a cross-sectional structure of a light source device 100 according to this embodiment.
As shown in FIG. 1, a light source device 100 according to this embodiment includes a semiconductor laser chip 1 (optical element) that emits laser light from an emitter 2, and a laser light emitted from the semiconductor laser chip 1 (emitter 2). Are provided with a wavelength conversion element 20 disposed on the optical path and an external resonator 30 constituting a resonator structure with the semiconductor laser chip 1. In the following description, the direction parallel to the optical axis of the laser light emitted from each emitter 2 is defined as the Z-axis direction, the arrangement direction of the emitters 2 perpendicular to the Z-axis is the X-axis direction, both the Z-axis and the X-axis. A description will be made using an XYZ orthogonal coordinate system in which the direction perpendicular to the Y-axis direction is set.

    In this embodiment, the semiconductor laser chip 1 has a size of 10 × 1 × 0.1 (unit is mm), for example, and the wavelength conversion element 20 has a size of 10 × (0.5 to 1) × 5 (unit). Were used, and the external resonator 30 was 10 × 2 × 5 (unit is mm).

  The light source device 100 includes a first semiconductor laser chip 1A (first optical element) and a second semiconductor laser chip 1B (second first optical element). These first and second semiconductor laser chips 1A and 1B are made of a material such as GaAs, for example.

  The first and second semiconductor laser chips 1A and 1B are mounted on the base member 7 with a bonding material or the like. The base member 7 is made of, for example, a ceramic material such as AlN, SiC, AlSiC, a composite material such as Cu-W, Cu-Mo, or BeO, or a carbon material such as carbon (C), graphite, or diamond. It is made of a conductive material. As the bonding material, for example, a conductive low melting point material such as In, Pb, or Sn can be used alone. For example, an alloy-like conductive low melting point material such as AuSn, AgSn, InAg, InSn, PbSn, SnBi, and AnAgCu can be used.

  The semiconductor laser chip may be fixed on the submount, and the submount may be fixed on the base member 7. As a result, the submount material and the semiconductor laser chip 1 can be accurately positioned with respect to the reference point on the base member 7 in the X-axis direction and the Y-axis direction.

  On the base member 7, an optical component holding member 8 extending in the direction of the optical axis (Z-axis in the figure) of laser light emitted from each emitter 2 is fixed. The optical component holding member 8 is formed of, for example, the same material as that of the base member 7, and holds the wavelength conversion element 20 and the external resonator 30 at predetermined positions.

The wavelength conversion element 20 has a periodic polarization inversion structure, and is configured to convert the wavelength of incident light into light of a specific wavelength. For example, when the wavelength (first wavelength) of light emitted from the emitter 2 is 1064 nm (near infrared), the wavelength conversion element 20 converts this to a half wavelength (second wavelength) 532 nm. Produces green light. The wavelength conversion efficiency of the wavelength conversion element 20 is generally about 30 to 40%. That is, not all of the light emitted from the emitter 2 is wavelength-converted. The periodic domain-inverted structure is formed inside a crystal substrate of an inorganic nonlinear optical material such as lithium niobate (LN: LiNbO ₃ ) or lithium tantalate (LT: LiTaO ₃ ).

The external resonator 30 includes a Bragg grating inside, and transmits light of a specific wavelength (light of the emitter 2 before wavelength conversion) and light of other wavelengths (light of the emitter 2 after wavelength conversion). ) Is selectively reflected. The Bragg grating is formed, for example, by irradiating a glass layer such as alkali boroaluminosilicate glass mainly composed of SiO ₂ with ultraviolet rays having a predetermined wavelength, and forming interference patterns having different refractive indexes in the glass layer in layers. Yes.
The external resonator 30 can also be configured by combining a reflector and a bandpass filter or a dichroic mirror.

  FIG. 2 is a plan view showing the positional relationship between the first and second semiconductor laser chips 1A and 1B on the base member 7. FIG. As shown in FIG. 2, a plurality of emitters 2 are arranged in a line shape (20 in this embodiment) on the light emitting surfaces 3 of the first and second semiconductor laser chips 1A and 1B. The first and second semiconductor laser chips 1A and 1B are arranged and held on the base member 7 so as to be parallel to each other in the arrangement direction of the emitters 2 (X-axis direction in FIG. 2). .

  The first and second semiconductor laser chips 1A and 1B are mounted on the same plane by being fixed to the base member 7. Thereby, the height of each light emitting surface 3 becomes equal, alignment with respect to the wavelength conversion element 20 and the external resonator 30 becomes easy, and the assemblability of the light source device 100 is improved.

  In the present embodiment, as shown in FIG. 2, in the first and second semiconductor laser chips 1A and 1B, the emitters 2 are displaced from each other in the arrangement direction of the emitters 2 (X-axis direction in the figure). Is arranged. With this configuration, wavelength interference and thermal interference between the laser beams in the emitters 2 of the first and second semiconductor laser chips 1A and 1B, the wavelength conversion element 20, and the external resonator 30 when laser light is emitted are prevented. ing.

  Further, the light source device 100 is on the optical path of the laser light emitted from the emitter 2, and is disposed between the first and second semiconductor laser chips 1 A and 1 B and the wavelength conversion element 20, and the laser emitted from the emitter 2. A first mirror M1 and a second mirror M2 that reflect light are provided. Here, the first mirror M1 corresponds to the laser light emitted from the emitter 2 of the first semiconductor laser chip 1A, and the second mirror M2 is emitted from the emitter 2 of the second semiconductor laser chip 1B. This corresponds to the laser beam to be emitted.

  These first and second mirrors M1 and M2 include a reflective film 14 that reflects the laser light from the emitter 2. The reflective film 14 is formed of a thin film having excellent reflectivity, such as Al. That is, the first and second mirrors M1 and M2 are configured by forming the reflective film 14 on the surface of a transparent plate such as glass.

  The first and second mirrors M1 and M2 are arranged so that the optical path lengths from the first semiconductor laser chip 1A and the second semiconductor laser chip 1B to the wavelength conversion element 20 are equal. This facilitates alignment adjustment in the first and second semiconductor laser chips 1A and 1B, the wavelength conversion element 20, or the external resonator 30.

The laser light reflected by the first and second mirrors M1 and M2 is reflected on the optical path of the laser light in the first and second mirrors M1 and M2 and the wavelength conversion element 20, and is reflected by the external resonator 30. A first prism 50 that transmits the laser light wavelength-converted by the wavelength conversion element 20 is provided.
Furthermore, the light source device 100 includes a second prism 60 (optical member) that reflects the laser light after wavelength conversion that has passed through the first prism 50 and emits the laser light to the outside.

  The first prism 50 is made of optical glass such as BK7 and has an isosceles triangular prism shape. The side surface of the first prism 50 is composed of surfaces 50B and 50C including two sides sandwiching the apex angle of an isosceles triangle and a surface 50A including a hypotenuse. In the present embodiment, the apex angle is set to 90 °.

  The light incident surfaces 50B and 50C of the first prism 50 transmit light of a specific wavelength (light after wavelength conversion by the wavelength conversion element 20) and light of other wavelengths (same as laser light). A transflective film 51 that reflects light having a wavelength) is formed. The transflective film 51 is composed of a dielectric multilayer film.

  Similarly to the first prism 50, the second prism 60 is made of optical glass such as BK7 and has an isosceles triangular prism shape. The side surface of the second prism 60 is composed of two surfaces 60B and 60C that sandwich an apex angle of an isosceles triangle and a surface 60A that includes a slope. In the present embodiment, the apex angle is set to 90 °.

  The first prism 50 and the second prism 60 are bonded together by the surface 50A and the surface 60A. As a result, laser light is captured from the first prism 50 to the second prism 60.

  A reflection film 61 is formed on the surfaces 60B and 60C of the second prism 60 to reflect the laser light transmitted through the semi-transmissive reflection film 51 of the first prism 50 to the outside of the apparatus. The reflective film 61 is formed of a thin film having excellent reflectivity such as Al.

  The first and second mirrors M1 and M2 are adjusted so that the laser light from the emitter 2 (light along the Z direction in FIG. 1) is reflected by 90 ° and directed toward the first prism 50. Yes. Specifically, the first prism 50 allows the laser light reflected by the first and second mirrors M1 and M2 to enter the surfaces 50B and 50C at about 45 °. As a result, the first prism 50 can reflect the laser light along the extending direction of the wavelength conversion element 20 (Z-axis direction in FIG. 1), and the laser light can be efficiently incident on the wavelength conversion element 20. ing.

  The laser light of the first semiconductor laser chip 1A and the second semiconductor laser chip 1B reflected by the external resonator 30 and wavelength-converted by the wavelength conversion element 20 has the apex angle of the second prism 60 set to 90 °. Therefore, after being reflected by 90 ° on the surface 60B, it is again reflected by 90 ° on the surface 60C and emitted outside the apparatus in a substantially parallel state along the Z-axis direction in FIG.

  With the above configuration, the laser light emitted from the emitter 2 of the first semiconductor laser chip 1A is reflected by the first mirror M1 and further reflected by the transflective film 51 provided on the surface 50B of the first prism 50. In addition, when passing through the wavelength conversion element 20, a part of the light is converted to a half wavelength and is emitted to the outside of the apparatus through the external resonator 30. Further, the light that has not been wavelength-converted when passing through the wavelength conversion element 20 is reflected by the external resonator 30 and is wavelength-converted when it passes through the wavelength conversion element 20 again, so that the above-mentioned half provided on the surface 50B. The light enters the second prism 60 by the transmission / reflection film 51. The laser light incident on the second prism 60 is reflected in order from the surface 60B and the surface 60C and is emitted to the outside.

  The laser light emitted from the emitter 2 of the second semiconductor laser chip 1B is reflected by the second mirror M2 and further reflected by the transflective film 51 provided on the surface 50C of the first prism 50. When passing through the conversion element 20, a part of the light is converted to a half wavelength and emitted through the external resonator 30 to the outside of the apparatus. The light that has not been wavelength-converted when passing through the wavelength conversion element 20 is reflected by the external resonator 30 and wavelength-converted when it passes through the wavelength conversion element 20 again, and is formed on the surface 50C. The light enters the second prism 60 by the transmission / reflection film 51. The laser light incident on the second prism 60 is reflected in order from the surface 60B and the surface 60C and is emitted to the outside.

  Subsequently, a process until output light is obtained by driving the light source device 100 according to the present embodiment will be described with reference to FIG.

  In FIG. 1, O <b> 1 indicates light emitted from the emitter 2 of the first semiconductor laser chip 1 </ b> A, converted to a half wavelength by the wavelength conversion element 20, and emitted to the outside through the external resonator 30. In FIG. 1, L1 is emitted from the emitter 2 of the first semiconductor laser chip 1A, reflected by the external resonator 30 without being converted into a half wavelength by the wavelength conversion element 20, and transmitted through the wavelength conversion element 20 again. In this case, the light emitted to the outside after being converted to a half wavelength is shown. In FIG. 1, although the optical paths L1 and O1 of the first semiconductor laser chip 1A between the first prism 50 and the external resonator 30 are shown at different positions, this is shown at different positions for convenience of explanation. It is only in the same position.

  In the figure, O2 indicates light emitted from the emitter 2 of the second semiconductor laser chip 1B, converted to a half wavelength by the wavelength conversion element 20, and emitted outside through the external resonator 30. Also, in the figure, L2 is emitted from the emitter 2 of the second semiconductor laser chip 1B, is reflected by the external resonator 30 without being converted to a half wavelength by the wavelength conversion element 20, and passes through the wavelength conversion element 20 again. It shows light that is converted to half the wavelength. In FIG. 1, although the optical paths L2 and O2 of the second semiconductor laser chip 1B between the first prism 50 and the external resonator 30 are shown at different positions, this is shown at different positions for convenience of explanation. It is only in the same position.

  The laser light emitted from the emitter 2 of the first semiconductor laser chip 1A is reflected by the first mirror M1 and travels toward the first prism 50. Further, the laser light is reflected by the transflective film 51 formed on the surface 50 </ b> B of the first prism 50 and enters the wavelength conversion element 20. Part of the laser light incident on the wavelength conversion element 20 is converted to a half wavelength by the wavelength conversion element 20, passes through the external resonator 30, and is emitted as laser light O1 to the outside of the apparatus.

  The wavelength conversion efficiency of the wavelength conversion element 20 is about 30 to 40% as described above. Therefore, the laser light that has not been wavelength-converted by the wavelength conversion element 20 is reflected by the external resonator 30 and is incident on the wavelength conversion element 20 again. The reflected light is converted into half light by passing through the wavelength conversion element 20, and after passing through the semi-transmissive reflection film 51 formed on the surface 50 </ b> B of the first prism 50, the surface 60 </ b> B and the surface of the second prism 60. By being reflected in order of 60C, the laser beam L1 is emitted to the outside of the apparatus. The laser light that has not undergone wavelength conversion when passing through the wavelength conversion element 20 is sequentially reflected by the surface 50B (semi-transmissive reflection film 51) of the first prism 50 and the first mirror M1, and the first semiconductor laser chip 1A. And becomes a new laser beam generation source.

  On the other hand, the laser light emitted from the emitter 2 of the second semiconductor laser chip 1B is reflected by the second mirror M2 and travels toward the first prism 50. Further, the laser light is reflected by the transflective film 51 formed on the surface 50 </ b> C of the first prism 50 and enters the wavelength conversion element 20. A part of the laser light incident on the wavelength conversion element 20 is converted to a half wavelength by the wavelength conversion element 20, passes through the external resonator 30, and is emitted as laser light O2 to the outside of the apparatus.

  The laser light that has not been wavelength-converted by the wavelength conversion element 20 is reflected by the external resonator 30 and is incident on the wavelength conversion element 20 again. The reflected light is wavelength-converted into half light by passing through the wavelength conversion element 20, passes through the transflective film 51 formed on the surface 50 </ b> C of the first prism 50, and then the surfaces 60 </ b> B and 60 </ b> C of the second prism 60. And is emitted as laser light L2 outside the apparatus. The laser light that has not been wavelength-converted when passing through the wavelength conversion element 20 is sequentially reflected by the surface 50C (semi-transmissive reflection film 51) of the first prism 50 and the second mirror M2, and the second semiconductor laser chip. The laser beam enters 1B and becomes a new laser beam generation source.

  Here, as shown in FIG. 1, a laser beam emitted from the emitter 2 of the first semiconductor laser chip 1A and incident on the wavelength conversion element 20 via the first mirror M1 and the first prism 50; The distance from the laser light emitted from the emitter 2 of the second semiconductor laser chip 1B and incident on the wavelength conversion element 20 via the second mirror M2 and the second prism 60 is the same as that of the first semiconductor laser chip 1A and the first semiconductor laser chip 1A. It is set sufficiently smaller than the interval between the emitters 2 of the two semiconductor laser chips 1B. Therefore, the width of the wavelength conversion element 20 on which the laser light of the emitter 2 in the first semiconductor laser chip 1A and the second semiconductor laser chip 1B is incident can be suppressed.

  According to the light source device 100 according to the present embodiment, the laser light emitted from the emitters 2 of the two optical elements (first and second semiconductor laser chips 1A and 1B) is allowed to pass through the single wavelength conversion element 20. Therefore, the cost and size of the apparatus can be reduced. Further, since the laser light wavelength-converted when passing through the wavelength conversion element 20 again can be extracted as the output of the light source device 100, high efficiency can be realized. In addition, since the laser beams emitted from the first and second semiconductor laser chips 1A and 1B can be synthesized, high output light can be obtained.

  Further, in the light source device 100 according to the present embodiment, as shown in FIG. 1, the light is emitted from the emitter 2 of the first semiconductor laser chip 1 </ b> A and passes through the first mirror M <b> 1 and the first prism 50 to the wavelength conversion element 20. The interval between the incident laser beam and the laser beam emitted from the emitter 2 of the second semiconductor laser chip 1B and incident on the wavelength conversion element 20 via the second mirror M2 and the second prism 60 is set to be first. This is sufficiently smaller than the distance between the semiconductor laser chip 1A and the second semiconductor laser chip 1B. Therefore, high wavelength conversion efficiency can be obtained by ensuring that the laser light emitted from the emitters 2 of the first and second semiconductor laser chips 1A and 1B is incident on the wavelength conversion effective region of the wavelength conversion element 20.

Further, as shown in FIG. 2, the first and second semiconductor laser chips 1A and 1B are arranged in a state in which the emitters 2 are displaced in the arrangement direction of the emitters 2, so that the first and second semiconductor laser chips 1A and 1B are arranged. Wavelength interference and thermal interference between laser beams inside the emitter 2 and the wavelength conversion element 20 of the laser chips 1A and 1B and the external resonator 30 can be prevented, and the reliability as the light source device 100 is high. It has become a thing.
Although not shown, in the first semiconductor laser chip 1A shown in FIG. 2, a plurality of emitter rows in which the emitters 2 are arranged in a line can be formed. According to this configuration, the density of laser light incident on the wavelength conversion element from each optical element is increased, and the laser light output can be further increased. Moreover, since the length in the column direction can be shortened by adopting this configuration, the light source device can be reduced in size.

  Further, since the light source device 100 includes the first prism 50 whose apex angle is set to 90 °, it is easy to adjust the optical axis between the first prism 50 and the first and second mirrors M1 and M2. can do. Furthermore, the first prism 50 having an apex angle of 90 ° can be easily manufactured, and the cost can be reduced.

(Second Embodiment)
Next, a second embodiment of the light source device of the present invention will be described with reference to the drawings. FIG. 3 is a diagram showing a schematic configuration of the light source device 200 according to the present embodiment. In the light source device 200 according to the present embodiment, as shown in FIG. 3, the apex angle of the first prism 50 is set to an acute angle (less than 90 °). In addition, the same code | symbol is attached | subjected about the same member and structure as the said embodiment, and the detailed description is abbreviate | omitted or simplified. Further, O1, O2, L1, and L2 in FIG. 3 correspond to the laser light described in the first embodiment.

  The first mirror M1 and the second mirror M2 are laser beams emitted from the emitters 2 of the first semiconductor laser chip 1A and the second semiconductor laser chip 1B, and the laser beams after reflection on the surfaces 50B and 50C of the first prism 50. The mounting angle is adjusted so that the light is parallel to the Z-axis direction in FIG.

  Of the laser light emitted from the emitter 2 of the second semiconductor laser chip 1B, the laser light is reflected by the external resonator 30 and wavelength-converted when passing through the wavelength conversion element 20 again (return path of the wavelength conversion element 20). The laser beam L2 is incident on the vicinity of the apex angle of the second prism 60.

Then, the process until the light source device 200 which concerns on this embodiment is driven and output light is obtained is demonstrated.
In the present embodiment, as described above, the apex angle of the first prism 50 is set to an acute angle, and the laser light emitted from the emitter 2 of the second semiconductor laser chip 1B and wavelength-converted in the return path of the wavelength conversion element 20 is used. Is incident in the vicinity of the apex angle of the second prism 60, and the interval between the laser beams emitted from the emitters 2 of the first and second semiconductor laser chips 1A and 1B is compared with the configuration of the first embodiment described above. And get closer.

(projector)
Next, a configuration of the projector 500 will be described as an example of an image display device to which the light source device is applied. FIG. 4 is a schematic diagram showing an outline of the optical system of the projector 500.
In FIG. 4, a projector 500 includes, for example, the light source device 100, a liquid crystal panel 520 as a light modulation device, polarizing plates 531 and 532, a cross dichroic prism 540, a projection lens 550, and the like. The liquid crystal light valve 530 is configured by the liquid crystal panel 520, the polarizing plate 531 provided on the light incident side thereof, and the polarizing plate 532 provided on the light emission side.

  The light source device 100 includes a red light source device 100R that emits red laser light, a blue light source device 100B that emits blue laser light, and a green light source device 100G that emits green laser light. These light source devices 100 (100R, G, B) are arranged so as to face the three side surfaces of the cross dichroic prism 540, respectively. In FIG. 7, the red light source device 100R and the blue light source device 100B face each other with the cross dichroic prism 540 interposed therebetween, and the projection lens (projection device) 550 and the green light source device 100G face each other. However, these positions can be switched as appropriate.

  The liquid crystal panel 520 uses, for example, a polysilicon TFT (Thin Film Transistor) as a switching element. The color light emitted from each light source device 100 enters the liquid crystal panel 520 via the incident-side polarizing plate 531. The light incident on the liquid crystal panel 520 is modulated according to image information and emitted from the liquid crystal panel 520. Of the light modulated by the liquid crystal panel 520, only specific linearly polarized light passes through the exit-side polarizing plate 532 and travels toward the cross dichroic prism 540.

The cross dichroic prism 540 is an optical element that combines color lights modulated by the liquid crystal panels 520 to form a color image. The cross dichroic prism 540 has a substantially square shape in plan view in which four right-angle prisms are bonded. Two kinds of dielectric multilayer films are provided in an X shape at the interface of these four right-angle prisms. These dielectric multilayer films reflect the color lights emitted from the liquid crystal panels 320 facing each other, and transmit the color lights emitted from the liquid crystal panel 520 opposed to the projection lens 550.
In this manner, the color lights modulated by the liquid crystal panels 520 are combined to form a color image.
The projection lens 550 is configured as a combined lens in which a plurality of lenses are combined. The projection lens 550 enlarges and projects the color image CI.

As described above, since the projector 500 uses the light source device 100 that is small, low-cost, and obtains high output as described in the first embodiment, the projector 500 can project a small and high-definition image. Can be provided at low cost.
In this application example, the light source device 100 (100R, G, B) according to the first embodiment is used, but some or all of these are replaced with the light source device 200 according to the second embodiment. Also good.

(Monitor device)
Next, a configuration example of a monitor device 600 to which the light source device 100 according to the first embodiment is applied will be described. FIG. 5 is a schematic diagram showing an outline of the monitor device. The monitor device 600 includes a device main body 610 and an optical transmission unit 620. The apparatus main body 610 includes the light source device 100 of the first embodiment described above as the light source 604.

  The light transmission unit 620 includes two light guides 621 and 622 on the light sending side and the light receiving side. Each of the light guides 621 and 622 is a bundle of a large number of optical fibers and can send laser light to a distant place. A light source 604 is disposed on the incident side of the light guide 621 on the light transmission side, and a diffusion plate 623 is disposed on the emission side thereof. The laser light emitted from the light source 604 is transmitted to the diffusion plate 623 provided at the tip of the light transmission unit 620 through the light guide 621 and is diffused by the diffusion plate 623 to irradiate the subject.

  An imaging lens 624 is also provided at the tip of the light transmission unit 620, and reflected light from the subject can be received by the imaging lens 624. The received reflected light travels through the light guide 622 on the receiving side and is sent to a camera 611 serving as an imaging unit provided in the apparatus main body 610. As a result, an image based on the reflected light obtained by irradiating the subject with the laser light emitted from the light source 604 can be captured by the camera 611.

According to the monitor device 600 configured as described above, the subject can be irradiated with bright light without unevenness in luminance by the light source 604 that is small, low-cost, and high in output, so that the subject can be clearly imaged by the camera 411. In addition, a small size can be obtained at a low cost.
In this application example, the light source device 100 according to the first embodiment is used, but this may be replaced with the light source device 200 according to the second embodiment.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the prism (second prism 60) is used as an optical member that reflects the laser light after wavelength conversion that has passed through the first prism 50 and emits the laser light to the outside. However, a reflection mirror may be used. it can.

  In the above-described embodiment, the plurality of emitters 2 are arranged in a line shape on the light emitting surfaces 3 of the first semiconductor laser chip 1A and the second semiconductor laser chip 1B. At least one of the semiconductor laser chip 1A and the second semiconductor laser chip 1B may include a plurality of (for example, two) emitter rows in which the emitters 2 are arranged in a line. In this way, the density of the laser light incident on the wavelength conversion element 20 from the optical elements (the first semiconductor laser chip 1A and the second semiconductor laser chip 1B) is increased, and higher-power laser light can be obtained. .

  In the application example described above, an example of a projector using three light modulation elements has been described. However, the light source devices 100 and 200 according to the first and second embodiments have one, two, or four light modulation devices. The present invention can also be applied to the projectors used above. In the application example described above, the transmissive projector has been described. However, the light source device of the present invention can also be applied to a reflective projector. Here, “transmission type” means that the light modulation element is a type that transmits light, and “reflection type” means that the light modulation element is a type that reflects light. ing. The light source device of the present invention can also be applied to a scanning projector that scans laser light emitted from a light source device toward a screen by a MEMS mirror or the like.

It is a figure which shows schematic structure of the light source device which concerns on 1st embodiment. It is a top view of a semiconductor laser chip. It is a figure which shows schematic structure of the light source device which concerns on 2nd embodiment. It is a figure which shows schematic structure of a projector. It is a figure which shows schematic structure of a monitor apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser chip (optical element), 1A ... First semiconductor laser chip (first optical element), 1B ... Second semiconductor laser chip (second optical element), 2 ... Emitter, 11 ... Transflective film, 11A DESCRIPTION OF SYMBOLS ... Semi-transmissive reflective film, 11B ... Semi-transmissive reflective film, 20 ... Wavelength conversion element, 30 ... External resonator, 50 ... First prism, 60 ... Second prism (optical member), 100, 200 ... Light source device, 500 ... Projector, 520 ... Liquid crystal panel (light modulation element), 550 ... Projection lens (projection device), 600 ... Monitor device, M1 ... First mirror, M2 ... Second mirror

Claims (10)

A resonator structure is formed between an optical element that emits laser light from a plurality of emitters arranged in a line, a wavelength conversion element that is disposed on an optical path of laser light emitted from the emitter, and the optical element. An optical device comprising: an external resonator comprising:
A first optical element and a second optical element arranged in parallel;
A first light beam is disposed between the first optical element and the wavelength conversion element in the optical path of the laser light emitted from the first optical element, and reflects the first laser light emitted from the first optical element. Mirror,
And disposed between the second optical element and the wavelength conversion element in the optical path of the laser light emitted from the second optical element, and reflects the second laser light emitted from the second optical element; With two mirrors,
The first laser beam reflected by the first mirror and the second laser beam reflected by the second mirror are reflected and reflected by the external resonator and wavelength-converted by the wavelength conversion element. A first prism that transmits the first laser light and the second laser light;
An optical member for reflecting the first laser light after wavelength conversion and the second laser light transmitted through the first prism and emitting them to the outside.   The light source device according to claim 1, wherein the first optical element and the second optical element are mounted on the same plane.   3. The light source device according to claim 1, wherein the first optical element and the second optical element are arranged in a state in which the emitters are displaced from each other in the arrangement direction of the emitters.   The light source device according to claim 1, wherein an apex angle of the first prism is set to 90 °.   The light source device according to claim 1, wherein an apex angle of the prism is set to an acute angle.   The optical member includes a second prism that takes out laser light reflected by the external resonator and wavelength-converted by the wavelength conversion element in a predetermined direction, and the second prism has an apex angle set to 90 °. The light source device according to claim 1, wherein the light source device is a light source device.   The light source device according to claim 1, wherein at least one of the first optical element and the second optical element includes a plurality of emitter rows in which the emitters are arranged in a line shape. .   The said 1st, 2nd mirror is arrange | positioned so that the optical path length from the said 1st optical element and a 2nd optical element to the said wavelength conversion element may be made equal. The light source device according to one item.   A light source device according to any one of claims 1 to 8, a light modulation element that modulates laser light emitted from the light source device according to image information, and an image formed by the light modulation element And a projection device.   A monitor device comprising: the light source device according to claim 1; and an imaging unit that images a subject irradiated by the light source device.

Images