JP2009117573A - Light source apparatus, projector, and monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source apparatus that can be miniaturized and made inexpensive by allowing one wavelength conversion element to correspond to an array of emitters, and to provide a projector and a monitoring device. <P>SOLUTION: The light source apparatus 100 includes: a light element 1 having a plurality of rows of emitters A1, A2 where emitters 2 for emitting laser beams are arranged in a line; the wavelength conversion element 20 arranged on an optical path of laser beams emitted from the emitters 2 of the light element 1; an external resonator 30 for composing a resonator structure with the light element 1; a half-transparent reflection mirror M that is provided on the optical path of laser beams between the light element 2 and the wavelength conversion element 20, transmits laser beams emitted from the light element 1, and reflects laser beams that are reflected by the external resonator 30 and of which the wavelength is converted by the wavelength conversion element 20; and an optical member M3 for further reflecting the laser beams reflected by the half-transparent reflection mirror M for emitting to the 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

  By the way, the wavelength conversion element generally has a plate shape, and it is difficult to increase the thickness in terms of manufacturing technology. For this reason, in the prior art, a wavelength conversion element is provided for each column of the array. Therefore, the conventional light source device has a problem that the light source device is enlarged by providing a plurality of wavelength conversion elements for each column of the array, and the cost of the light source device is increased by providing a plurality of wavelength conversion elements.

  The present invention has been made in view of such circumstances, and by enabling one wavelength conversion element to correspond to an array of emitters, a light source device that can be reduced in size and cost, It is an object to provide a projector and a monitor device.

The present invention employs the following configuration in order to solve the above problems.
That is, the light source device of the present invention is arranged on an optical element having a plurality of emitter rows in which emitters emitting laser light are arranged in a line, and on the optical path of the laser light emitted from the emitter of the optical element. Provided on the optical path of the laser beam between the wavelength conversion element, the external resonator constituting the resonator structure between the optical element, and the optical element and the wavelength conversion element, and emitted from the optical element A transflective mirror that transmits laser light and reflects the laser light reflected by the external resonator and wavelength-converted by the wavelength conversion element; and further reflects the laser light reflected by the transflective mirror. And an optical member that emits to the outside.

  According to the light source device of the present invention, since one wavelength conversion element is provided for an optical element that emits laser light from a plurality of emitter arrays, it is possible to reduce the cost and the size of the apparatus. Further, by providing an array of emitters, high-power laser light can be obtained even if it is small.

In the light source device, it is preferable that the emitters are arranged such that an interval between the emitter columns is narrower than an interval between adjacent emitters in the arrangement direction in the same column.
According to this configuration, the emitters in adjacent emitter rows can be arranged close to each other. Therefore, further downsizing of the light source device can be realized by reducing the optical element. At this time, the laser light emitted from the emitter of each emitter row can be reliably incident on the wavelength conversion effective range of the wavelength conversion element.
Furthermore, the emitters are more preferably arranged in a staggered manner.
In this manner, the optical elements can be further reduced in size by arranging the emitters in a staggered manner so that the emitters of adjacent emitter rows are closer to each other.
Furthermore, it is desirable that the plurality of emitters be arranged so that the distances to other emitters arranged close to each other are equal.
In this way, since the distances between the other emitters arranged close to each other are equal, it is possible to prevent wavelength interference and thermal interference between the laser beams of the adjacent emitters when the laser light is emitted.

In the light source device, the transflective mirror includes a plurality of mirrors provided corresponding to the emitter rows, and each of the mirrors transmits the laser light emitted from the corresponding emitter row. Preferably, a transflective film that reflects the laser beam reflected by the external resonator and wavelength-converted by the wavelength conversion element is preferably formed.
According to this configuration, since the transflective mirror is composed of a plurality of mirrors, for example, by providing a mirror for each emitter row, the emission direction of the laser light can be adjusted, and the reliability of the light source device can be improved. it can.
At this time, it is more preferable that the transflective film is formed so that the transflective film does not overlap an incident region of the laser beam reflected by another mirror.
According to this configuration, the light reflected by the other mirror is incident on the region where the transflective film is not provided, and can be directed toward the optical member by passing through the mirror as it is. Therefore, even when the transflective mirror is composed of a plurality of mirrors, the light of each emitter can be used efficiently.

In the light source device, a first optical system and a second optical system each including the optical element, the wavelength conversion element, the external resonator, and the transflective mirror are configured. The optical member is preferably used in common in the optical system.
According to this structure, compared with the case where two said light source devices are combined, by using an optical member in common, the size of the device can be reduced and a stronger light output can be obtained.

  As another aspect of the light source device of the present invention, there are provided an optical element having a plurality of emitter rows in which a plurality of emitters are arranged in a line, and emitting laser light from the emitter, and emitting from the emitter of the optical element. A wavelength conversion element disposed on the optical path of the laser beam, an external resonator constituting a resonator structure with the optical element, and provided on the optical path of the optical element and the wavelength conversion element, A prism that reflects the laser light emitted from the optical element to be incident on the wavelength conversion element and is emitted by reflecting the laser light reflected by the external resonator and wavelength-converted by the wavelength conversion element. And a section.

  According to the light source device of the present invention, it is possible to provide a low-cost and small-sized light source device by replacing the transflective mirror and the optical member with a prism portion. Can be obtained.

  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)
As shown in FIG. 1, a light source device 100 according to the present embodiment includes a semiconductor laser chip 1 (optical element), and a wavelength conversion element 20 disposed on the optical path of laser light emitted from the semiconductor laser chip 1. And an external resonator 30 constituting a resonator structure with the semiconductor laser chip 1. The semiconductor laser chip 1 has a size of 10 × 1.5 × 0.1 (the unit is mm), and the wavelength conversion element 20 has a size of 10 × (0.5 to 1) × 5 (the unit is any And the external resonator 30 has a size of 10 × 2 × 5 (the unit is mm).

  A plurality of emitters 2 for emitting laser light L1 are formed on the light emitting surface 3 of 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.

  FIG. 2 is a plan view of the semiconductor laser chip 1. As shown in FIG. 2, the light emitting surface 3 of the semiconductor laser chip 1 is provided with a plurality of emitter rows in which emitters 2 are arranged in a line (20 in this embodiment) (in this embodiment, 2). Column). Hereinafter, the left emitter row in FIG. 2 is referred to as a first emitter row A1, and the right emitter row in FIG. 2 is referred to as a second emitter row A2.

In FIG. 1, O <b> 1 indicates light emitted from the emitter 2 of the first emitter array A <b> 1, converted to the second wavelength by the wavelength conversion element 20, and emitted from the external resonator 30. In FIG. 1, L1 is emitted from the emitter 2 of the first emitter array A1, is emitted without being converted into the second wavelength by the wavelength conversion element 20, is reflected by the external resonator 30, and is reflected by the wavelength conversion element 20 The light that is converted to the second wavelength when transmitting again is shown.
In the figure, O2 indicates light emitted from the emitter 2 of the second emitter array A2, converted to the second wavelength by the wavelength conversion element 20, and emitted from the external resonator 30. In the same figure, L2 is emitted from the emitter 2 of the first emitter array A2, emitted without being converted into the second wavelength by the wavelength conversion element 20, reflected by the external resonator 30, and the wavelength conversion element 20 The light that is converted to the second wavelength when transmitting again is shown.

  The emitter 2 is arranged such that the interval between the first emitter row A1 and the second emitter row A2 is narrower than the interval between adjacent emitters in the arrangement direction (X-axis direction in FIG. 2) in the same row. ing. As a result, the semiconductor laser chip 1 can be reduced in size by arranging the emitters 2 in the adjacent emitter arrays A1 and A2 close to each other. Specifically, in the present embodiment, the emitters 2 of the first emitter array A1 and the second emitter array A2 are respectively arranged in a staggered manner.

  FIG. 3 is an enlarged view of a main part of the light emitting surface 3 of the semiconductor laser chip 1. As shown in FIG. 3, an equilateral triangle is formed by connecting the centers of the adjacent emitters 2a and 2b in the first emitter row A1 and the centers of the emitters 2c of the second emitter row A2 adjacent to the emitters 2a and 2b. It has come to be. That is, the emitter 2a has the same distance to the other emitters 2b and 2c arranged close to each other. Specifically, in the present embodiment, the diameter of each emitter 2 is 240 μm, the distance between adjacent emitters 2 in the same emitter row is 300 μm, and the distance between adjacent emitters 2 in the first and second emitter rows A1 and A2 is set. The thickness was 300 μm. By arranging the emitters 2a, 2b, and 2c arranged adjacent to each other at an equal distance in this way, it is possible to prevent wavelength interference and thermal interference between the laser beams of the adjacent emitters 2 when emitting the laser light. .

  The semiconductor laser chip 1 is fixed on the base member 7 with a bonding material or the like. 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.

  The semiconductor laser chip 1 is formed using a material such as GaAs, for example. The submount material 6 and the base member 7 are made of, for example, a ceramic material such as AlN, SiC, and AlSiC, a composite material such as Cu—W, Cu—Mo, and BeO, or carbon (C), graphite, diamond, and the like. It is made of a high thermal conductivity material such as a carbon-based material. As the bonding material, for example, a conductive low melting point material such as In, Pb, or Sn can be used alone. Further, for example, an alloy-like conductive low melting point material such as AuSn, AgSn, InAg, InSn, PbSn, SnBi, or AnAgCu may be used.

  On the base member 7, an optical component holding member 8 extending in the optical axis L 1, O 1, L 2, O 2 (Z axis in the drawing) direction of the semiconductor laser chip 1 is fixed. The optical component holding member 8 is formed of the same material as that of the base member 7, for example.

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 laser beam emitted from the semiconductor laser chip 1 is transmitted on the optical path of the laser beam in the semiconductor laser chip 1 and the wavelength conversion element 20 and is reflected by the external resonator 30 and wavelength-converted by the wavelength conversion element 20. A transflective mirror M on which a transflective film 11 that reflects light is formed is provided.

  In the present embodiment, the transflective mirror M includes a first mirror M1 and a second mirror M2 arranged to face each other. The first mirror M1 and the second mirror M2 are provided corresponding to the first emitter row A1 and the second emitter row A2, respectively.

  The light source device 100 further includes a third mirror (optical member) M3 that reflects the laser beam reflected by the transflective mirror M and emits the laser beam to the outside. The third mirror M3 is disposed to face the first and second mirrors M1 and M2 with a predetermined angle, and includes a reflective film 14 on the facing surface side. The reflective film 14 is formed of a thin film having excellent reflectivity such as Al. The third mirror M3 is configured by forming a thin film having excellent reflectivity such as Al as the reflective film 14 on the surface of a transparent plate such as glass.

  Specifically, in the present embodiment, the first and second mirrors M1 and M2 reflect light of a specific wavelength (light after wavelength conversion by the wavelength conversion element 20), and light of other wavelengths (laser light). Transflective films 11A and 11B that respectively transmit light having the same wavelength as that of FIG. That is, the first and second mirrors M1 and M2 are configured by forming dielectric multilayer films as the transflective films 11A and 11B on the surface of a transparent plate such as glass.

  As a result, the laser light emitted from the emitter 2 of the first emitter array A1 passes through the first mirror M1 (semi-transmissive reflective film 11A) and then passes through the wavelength conversion element 20 so that a part of the light is 1 It is converted to a wavelength of / 2 and emitted outside the apparatus. In addition, 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 to be converted into the first mirror M1 (semi-transmissive reflection film). 11A) is reflected to the second mirror M2 side. The reflected light is transmitted through the second mirror M2, reflected by the third mirror M3, and emitted to the outside.

  The laser light emitted from the emitters 2 of the second emitter array A2 passes through the second mirror M2 (semi-transmissive reflective film 11B) and then passes through the wavelength conversion element 20 so that part of the light is 1 / It is converted into a wavelength of 2 and emitted outside the apparatus. In addition, 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 to be converted into the second mirror M2 (semi-transmissive reflection film). 11B) is reflected toward the third mirror M3, reflected by the third mirror M3, and emitted to the outside.

  As described above, in addition to the light from the second emitter array A2, the light from the first emitter array A1 enters the second mirror M2. FIG. 4 is a plan view of the second mirror M2. Specifically, in the present embodiment, as shown in FIG. 4, the transflective film 11 </ b> B of the second mirror M <b> 2 overlaps the region B where the laser light reflected by the other mirror (first mirror M <b> 1) is incident. It is formed in a region A that should not be. Thereby, the light reflected by the first mirror M1 is incident on the region A of the second mirror M2 where the semi-transmissive reflective film 11B is not provided, and passes through the mirror as it is toward the third mirror M3. It has become. Therefore, the light of each emitter 2 in the emitter arrays A1 and A2 can be used efficiently. In the first mirror M1, a transflective film is formed at a position that overlaps each emitter 2 when viewed in plan, although not shown.

  Then, the process until the light source device 100 which concerns on this embodiment is driven and output light is obtained is demonstrated. In FIG. 1, the optical paths L1 and O1 in the laser light between the first mirror A1 and the external resonator 30 and the optical paths L2 and O2 in the laser light between the second mirror A2 and the external resonator 30 are respectively shown. Although shown in different positions, this is only shown in different positions for convenience of explanation, and originally exists in the same position.

  The semiconductor laser chip 1 emits laser light from the emitters 2 of the first and second emitter arrays A1 and A2. The laser light emitted from the emitter 2 of the first emitter array A1 passes through the first mirror M1 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 to the outside of the apparatus (corresponding to FIG. 1, optical path O1). ).

  The wavelength conversion efficiency of the wavelength conversion element 20 is about 30 to 40% as described above. Therefore, the light L1 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 L1 passes through the wavelength conversion element 20 and is converted into half of the light, reflected by the first mirror M1, and incident on the second mirror M2 that is disposed oppositely. At this time, as shown in FIG. 4, the transflective film 11B of the second mirror M2 is formed in the region A that does not overlap the region B on which the laser beam reflected by the first mirror M1 is incident. The reflected light L1 passes through the second mirror M2 and enters the third mirror M3. Then, the light incident on the third mirror M3 is reflected by the reflective film 14 and is emitted to the outside of the apparatus. Of the light L1, light that has not been wavelength-converted by the wavelength conversion element 20 passes through the first mirror M1, enters the emitter 2 of the first emitter array A1, and becomes a new laser light generation source.

  On the other hand, the laser light emitted from the emitter 2 of the second emitter array A2 passes through the first mirror M1 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 to the outside of the apparatus (corresponding to FIG. 1, optical path O2). ).

  The light L2 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 passes through the wavelength conversion element 20 and is converted into a wavelength of ½, reflected by the second mirror M2, and incident on the third mirror M3. Then, the light incident on the third mirror M3 is reflected by the reflective film 14 and is emitted to the outside of the apparatus. Of the light L2, the light that has not been wavelength-converted by the wavelength conversion element 20 passes through the second mirror M2, enters the emitter 2 of the second emitter array A2, and becomes a new laser light generation source. Therefore, the light of the emitter 2 in each emitter row A1, A2 can be used efficiently.

  According to this embodiment, one wavelength conversion element 20 is provided for the semiconductor laser chip 1 that emits laser light from the emitters 2 of the plurality of emitter rows (first and second emitter rows A1 and A2). Thus, the light from each of the emitter arrays A1 and A2 can be efficiently extracted to the outside. In addition, since one wavelength conversion element 20 is provided for the plurality of emitter arrays A1 and A2, cost reduction and size reduction can be realized. Further, by providing the arrayed emitter 2, high-power laser light can be obtained even if it is small.

  Further, in the light source device 100 according to the present embodiment, the emitter 2 has a distance between the first emitter row A1 and the second emitter row A2 between adjacent emitters in the arrangement direction (X-axis direction in FIG. 2) in the same row. Since it is arranged so as to be narrower than the interval (staggered), the laser light emitted from the emitters 2 of the emitter arrays A1 and A2 can be reliably incident on the wavelength conversion effective range of the wavelength conversion element 20. . Therefore, further downsizing of the light source device 100 can be realized by downsizing the semiconductor laser chip 1. Further, as shown in FIG. 3, the emitter 2a (first emitter array A1) has the same distance to the other emitters 2b and 2c (second emitter array A2) arranged in proximity to each other, so that laser light is emitted. In doing so, it is possible to minimize thermal interference between adjacent emitters 2.

(Second Embodiment)
Next, a second embodiment of the light source device of the present invention will be described with reference to the drawings. FIG. 5 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, unlike the above-described embodiment, the transflective mirror M is configured by a single mirror. Since the other configuration is the same as the configuration according to the first embodiment, the same reference numerals are given to the same members, and the detailed description is omitted or simplified.

  On the surface of the transflective mirror M, a solid translucent reflective film 11 is formed. Then, the process until the light source device 200 which concerns on this embodiment is driven and output light is obtained is demonstrated.

  In this embodiment, as shown in FIG. 5, the transflective mirror M is composed of a single mirror. Therefore, the above-described half-emitters in the emitter 2 of the first emitter array A1 and the emitter 2 of the second emitter array A2 are used. Unlike the above embodiment, the incident position of the transmissive reflection mirror M with respect to the semi-transmissive reflective film 11 is shifted in the Y-axis direction in FIG. Similarly, the reflection position of the laser beam in the semi-transmissive reflective film 11 of the semi-transmissive reflective mirror M is also shifted in the Y-axis direction in the figure with respect to the above embodiment.

Therefore, the optical paths L1 and O1 in the laser light between the first mirror A1 and the external resonator 30 are different from each other in the embodiment. Further, the optical paths L2 and O2 in the laser light between the second mirror A2 and the external resonator 30 are different from each other, unlike the above embodiment. As described above, in the light source device 200 according to the present embodiment, the optical axes of the laser beams emitted from the semiconductor laser chip 1 are four (L1, O1, L2, O2).
According to the present embodiment, the semi-transmissive reflective mirror M is configured from a single mirror, so that the alignment of the semi-transmissive reflective mirror M can be easily adjusted compared to the case where two mirrors are combined as in the above-described embodiment. It can be.

(Third embodiment)
Next, a third embodiment of the light source device of the present invention will be described with reference to the drawings. FIG. 6 is a diagram illustrating a schematic configuration of the light source device 300 according to the present embodiment. The light source device 300 according to the present embodiment includes a first optical system 350 and a second optical system 351 that include the semiconductor laser chip 1, the wavelength conversion element 20, the external resonator 30, and the semi-transmissive reflection mirror M in the first embodiment. It has. As described above, the transflective mirror M may be composed of a plurality of mirrors (first and second mirrors M1, M2), or may be composed of a single mirror. Furthermore, the light source device 300 according to the present embodiment further reflects the laser light reflected by the transflective mirror M out of the laser light emitted from the semiconductor laser chip 1 in the first optical system 350 and emits it to the outside. The common mirror (optical member) 352 is provided. Similarly, the light source device 300 according to the present embodiment further reflects the laser light reflected by the transflective mirror M out of the laser light emitted from the semiconductor laser chip 1 in the second optical system 351 to the outside. The common mirror 352 is provided as an optical member to be emitted. That is, the first and second optical systems 350 and 351 are optical members (common mirrors 352).

  When it is desired to provide a light source device that requires higher brightness, it is conceivable to configure a light source device by combining a plurality of light source devices according to the first embodiment described above. Even in this case, it is desirable to reduce the size of the light source device as much as possible. Therefore, in the present embodiment, as described above, by sharing the optical member (common mirror 352) in the first and second optical systems 350 and 351, as compared with the case where the two light source devices 100 are simply combined, It is possible to reduce the size of the apparatus and obtain a stronger light output. Although not shown, in this embodiment, the length of the emitter in the column direction can be shortened from that of the previous embodiment, thereby reducing the size of the device in the emitter column direction. The light output can be equivalent to the previous embodiment.

(Fourth embodiment)
Next, a fourth embodiment of the light source device of the present invention will be described with reference to the drawings. FIG. 7 is a diagram illustrating a schematic configuration of the light source device 400 according to the present embodiment. The light source device 400 according to the present embodiment has a configuration including a prism portion P as shown in FIG. 7 instead of the transflective mirror M in the first embodiment. Since the other configuration is the same as the configuration according to the first embodiment, the same reference numerals are given to the same members, and the detailed description is omitted or simplified.

  As shown in FIG. 7, the submount material 6 to which the semiconductor laser chip 1 is fixed via the bonding material is fixed on the base member 7, and toward the laser beam emission direction of the semiconductor laser chip 1. The wavelength conversion element 20 and the external resonator 30 are arranged in order. In the above embodiment, the light emitting surface 3 of the semiconductor laser chip 1 and the light incident surface 20a of the wavelength conversion element 20 face each other. However, in this embodiment, the light emitting surface 3 and the light incident surface 20a are orthogonal to each other. It is in a state.

  In the present embodiment, provided on the optical path of the semiconductor laser chip 1 and the wavelength conversion element 20, the laser light emitted from the semiconductor laser chip 1 is reflected and incident on the wavelength conversion element 20 and reflected by the external resonator 30. And a prism portion P that reflects the laser light wavelength-converted by the wavelength conversion element 20. The prism portion P guides laser light (Y-axis direction in FIG. 7) emitted from the light emitting surface 3 in the Z-axis direction in FIG.

  The prism portion P includes a first prism P1 provided on the semiconductor laser chip 1 side and a second prism P2 provided on the wavelength conversion element 20 side. The first prism P1 is made of optical glass such as BK7 and has an isosceles triangular prism shape. The side surface of the first prism P1 is composed of surfaces 300B and C including two sides sandwiching the apex angle of an isosceles triangle and a surface 300A including a hypotenuse. The second prism P2 is made of optical glass such as BK7 and has an isosceles triangular prism shape. The side surface of the prism P2 is composed of surfaces 301B and C including two sides sandwiching the apex angle of an isosceles triangle and a surface 301A including a hypotenuse. The inclination angle between the surface 300C and the surface 300A is set to 45 °.

  A transflective film 11 is formed between the surfaces 300B and 301B of the first and second prisms P1 and P2. A reflective film 14 is formed on the surfaces 300A and 301A of the first and second prisms P1 and P2.

  With such a configuration, the prism portion P emits light from the emitters 2 of the respective emitter arrays A1 and A2 to the wavelength conversion element 20 side, and is not wavelength-converted by the wavelength conversion element 20 and is converted by the external resonator 30. The reflected light is guided to each emitter 2. Further, the prism portion P reflects the laser light that has been wavelength-converted when reflected by the external resonator 30 and transmitted through the wavelength conversion element 20 among the light from the emitters 2 of the emitter arrays A1 and A2. To take it out of the device.

  Then, the process until the light source device 400 which concerns on this embodiment is driven and output light is obtained is demonstrated. In FIG. 7, O 1 ′ represents light emitted from the emitter 2 of the first emitter array A 1, converted to the second wavelength by the wavelength conversion element 20, and emitted from the external resonator 30. In FIG. 7, L1 ′ is emitted from the emitter 2 of the first emitter array A1, emitted without being converted into the second wavelength by the wavelength conversion element 20, reflected by the external resonator 30, and the wavelength conversion element. The light converted to the second wavelength when passing through 20 again is shown. In the figure, O2 ′ represents light emitted from the emitter 2 of the second emitter array A2, converted to the second wavelength by the wavelength conversion element 20, and emitted from the external resonator 30. In the same figure, L2 ′ is emitted from the emitter 2 of the first emitter array A2, emitted without being converted into the second wavelength by the wavelength conversion element 20, reflected by the external resonator 30, and the wavelength conversion element. The light converted to the second wavelength when passing through 20 again is shown. The optical paths L1 ′ and O1 ′ in the laser light between the first prism P1 and the external resonator 30 and the optical paths L2 ′ and O2 ′ in the laser light between the second prism P2 and the external resonator 30 are respectively shown. Although shown in different positions, this is only shown in different positions for convenience of explanation, and originally exists in the same position.

  The semiconductor laser chip 1 emits laser light from the emitters 2 of the first and second emitter arrays A1 and A2. The laser light emitted from the emitter 2 of the first emitter array A1 enters from the surface 301A of the second prism P2, and is reflected by the reflective film 14 provided on the surface 301C. The reflected light passes through the transflective film 11 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 to the outside of the device (FIG. 7, in the optical path O 1 ′). Correspondence).

  The light L1 ′ 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 L1 ′ passes through the wavelength conversion element 20 and is converted into a half light, and enters from the surface 300A of the first prism P1. Then, the light is reflected by the semi-transmissive reflective film 11 toward the surface 300B, and is reflected by the semi-transmissive reflective film 11 provided on the surface 301B to be emitted outside the apparatus. Of the light L1 ′, the light that has not been wavelength-converted by the wavelength conversion element 20 passes through the transflective film 11 and is reflected by the surface 301C of the second prism P2 to the emitter 2 of the first emitter array A1. Incident light becomes a new laser beam generation source.

  On the other hand, the laser light emitted from the emitter 2 of the second emitter array A2 is incident from the surface 301A of the second prism P2, is reflected by the reflective film 14 provided on the surface 301C, and passes through the semi-transmissive reflective film 11. Then, the light 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 to the outside of the device (FIG. 7, in the optical path O2 ′). Correspondence).

  The light L2 ′ 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 L2 ′ passes through the wavelength conversion element 20, is converted into a half light, and enters from the surface 300A of the first prism P1. Then, the light is reflected by the transflective film 11 toward the surface 301B, and is reflected by the reflective film 14 provided on the surface 301B to be emitted outside the apparatus. Of the light L2 ′, the light that has not been wavelength-converted by the wavelength conversion element 20 passes through the semi-transmissive reflection film 11, is reflected by the surface 301C of the second prism P2, and is incident on the emitter 2 of the second emitter array A2. By doing so, it becomes a generation source of a new laser beam.

  According to the present embodiment, the transflective mirror M of the above embodiment is substituted by the prism portion P. Therefore, it is possible to provide a light source device 400 that obtains high-power laser light at a low cost and in a small size as in the above embodiment.

  By applying the light source device 100, 200, 300, 400 as described above to an image display device or a monitor device, it is possible to improve the laser output in these devices. Hereinafter, application examples to the image display device and the monitor device will be described.

(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. 8 is a schematic diagram showing an outline of the optical system of the projector 500.
In FIG. 8, 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. However, a part or all of them is used as the light source device 200 according to the second to fourth embodiments. It may be replaced with ~ 400.

(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. 9 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 uneven brightness by the light source device 100 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 devices 200 to 400 according to the second to fourth embodiments.

  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.

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 to 400 of the first to fourth 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 principal part enlarged view of the light emission surface of a semiconductor laser chip. It is a figure which shows the planar structure of a 2nd mirror. 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 the light source device which concerns on 3rd embodiment. It is a figure which shows schematic structure of the light source device which concerns on 4th 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), 2 ... Emitter, 11 ... Semi-transmissive reflective film, 11A ... Semi-transmissive reflective film, 11B ... Semi-transmissive reflective film, 20 ... Wavelength conversion element, 30 ... External resonator, 100, 200 , 300, 400 ... light source device, 350 ... first optical system, 351 ... second optical system, 352 ... common mirror (optical member), 520 ... liquid crystal panel (light modulation element), 550 ... projection lens (projection device), 600 ... monitor device, A1 ... first emitter row (emitter row), A2 ... second emitter row (emitter row), M ... transflective mirror, M1 ... first mirror (mirror), M2 ... second mirror (mirror) ), M3 ... Third mirror (optical member), P ... Prism unit, P1 ... First prism, P2 ... Second prism

Claims (10)

An optical element having a plurality of emitter rows in which emitters emitting laser light are arranged in a line;
A wavelength conversion element disposed on an optical path of laser light emitted from the emitter of the optical element;
An external resonator constituting a resonator structure with the optical element;
Provided on the optical path of the laser light between the optical element and the wavelength conversion element, transmits the laser light emitted from the optical element, and is reflected by the external resonator and wavelength-converted by the wavelength conversion element A light source device comprising: a transflective mirror that reflects laser light; and an optical member that further reflects the laser light reflected by the transflective mirror and emits the laser light to the outside.   2. The light source device according to claim 1, wherein the emitters are arranged such that an interval between the emitter columns is narrower than an interval between the emitters adjacent in the arrangement direction in the same column.   The light source device according to claim 2, wherein the emitters are arranged in a staggered pattern.   The light source device according to claim 3, wherein the plurality of emitters are arranged so that distances to other emitters arranged close to each other are equal.   The transflective mirror includes a plurality of mirrors provided corresponding to the emitter rows, and each of the mirrors transmits the laser light emitted from the corresponding emitter row and reflects it by the external resonator. The light source device according to claim 1, wherein a transflective film that reflects the laser light wavelength-converted by the wavelength conversion element is formed.   6. The light source device according to claim 5, wherein the transflective film is formed so as not to overlap an incident region of laser light reflected by another mirror.   A first optical system and a second optical system each comprising the optical element, the wavelength conversion element, the external resonator, and the transflective mirror are configured, and the optical member is common in the first and second optical systems The light source device according to claim 1, wherein the light source device is used for a light source. An optical element having a plurality of emitter rows in which a plurality of emitters are arranged in a line, and emitting laser light from the emitter;
A wavelength conversion element disposed on an optical path of laser light emitted from the emitter of the optical element;
An external resonator constituting a resonator structure with the optical element;
Provided on the optical path of the optical element and the wavelength conversion element, the laser beam emitted from the optical element is reflected and incident on the wavelength conversion element and reflected by the external resonator and reflected by the wavelength conversion element And a prism unit that reflects the wavelength-converted laser beam and emits the laser beam to the outside.   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