JPWO2017026358A1 - Wavelength-coupled beam-coupled semiconductor laser source - Google Patents

Abstract

Laser oscillation is securely locked in a narrow band. A beam-coupled semiconductor laser light source includes a plurality of semiconductor laser chips, a plurality of fast axis (FA) direction cylindrical collimators, a single slow axis (SA) direction cylindrical collimator, and a dielectric. The multilayer filter 4, one partial reflecting mirror 5, one FA direction imaging lens 6, one SA direction imaging lens 7, and one multimode optical fiber 8 are provided. The dielectric multilayer filter 4 is fixed to the mount 14 at an angle θ1 corresponding to the lock wavelength. Only a specific wavelength of the laser beam 15 is transmitted by the dielectric multilayer filter 4. The laser beam 15 that has passed through the dielectric multilayer filter 4 is partially reflected by the partial reflection mirror 5, and passes through the dielectric multilayer filter 4, the SA-direction cylindrical collimator 3, and the FA-direction cylindrical collimator 2, and the semiconductor laser chip 1. Return to [Selection] Figure 1

Description

  The present invention relates to a beam-coupled semiconductor laser light source that collects laser beams from a plurality of semiconductor lasers and couples them to an optical fiber. The present invention relates to a wavelength locking method for a semiconductor laser. The present invention relates to a high-power semiconductor laser. The present invention relates to an excitation light source for a solid-state laser and a fiber laser. The present invention relates to a wavelength multiplexing technique. The present invention relates to a method of generating high-power laser light using wavelength multiplexing.

In Patent Document 1, laser light from a semiconductor laser array is used as an optical fiber by using an element that rotates a fast axis (FA) and a slow axis (SA) of a semiconductor laser. A technique for combining is disclosed. In addition, a technique is disclosed in which laser beams from two semiconductor laser arrays are coupled to a single optical fiber using a half-wave phase plate (polarization converter) and a polarization beam combiner.
Patent Document 2 discloses a method of laminating a plurality of semiconductor laser arrays and introducing laser light from the plurality of semiconductor laser arrays into an end face of a solid laser rod using a cylindrical lens.
In Patent Document 3, an external resonator type semiconductor laser is configured by combining an element that rotates a fast axis (FA) and a slow axis (SA) of a semiconductor laser and a semiconductor laser array. A technique is disclosed.
Patent Document 4 discloses a method of configuring an external resonator type semiconductor laser using a semiconductor laser array and an inclined reflecting mirror.
Patent Document 5 discloses a technique of coupling laser light to an optical fiber by using a plurality of reflecting mirrors provided on a step-shaped mount to bring laser light from a plurality of semiconductor lasers close to each other. .
Patent Document 6 discloses a method of rotating a fast axis (FA) and a slow axis (SA: Slow Axis) of a laser beam of a semiconductor laser by using a step-like reflector array. Yes.
Patent Document 7 discloses a technique in which laser beams from a plurality of semiconductor lasers are brought close to each other by providing a plurality of semiconductor lasers on a step-shaped mount.
Patent Document 8 discloses a method in which two rows of light sources composed of a plurality of semiconductor lasers are provided and light from the two rows of light sources is coupled to one optical fiber by polarization coupling using a phase plate. Yes.
Patent Document 9 discloses a method of performing wavelength locking using a volume Bragg diffraction grating.
Patent Document 10 discloses an external resonator type semiconductor laser using an interference filter. Also disclosed is a method for changing the oscillation wavelength of an external cavity semiconductor laser by changing the angle of the interference filter.
Patent Document 11 discloses the structure of a three-port device using a dielectric multilayer filter. Also disclosed is a technique for configuring a wavelength multiplexer by connecting three port devices in tandem.
Patent Document 12 discloses a technique of forming a wavelength multiplexer by adhering a dielectric multilayer filter to transparent flat glass.
Non-Patent Document 1 discloses the structure and characteristics of a dielectric multilayer filter.
Non-Patent Document 2 discloses a technique for obtaining a high-power laser beam by combining laser beams from a fiber laser using a diffraction grating.

Japanese Patent No. 3071360 JP-A-10-32359 Japanese Patent No. 4002286 Japanese Patent No. 4024270 US Pat. No. 4,978,197 US Pat. No. 5,808,323 US Pat. No. 6,124,973 US Pat. No. 7,738,178 U.S. Pat. No. 8,427,749 Japanese Patent Laid-Open No. 04-142900 JP 2003-185876 A JP 2003-149490 A

Mitsunobu Kominato, “Optical Thin Film Filter Design”, Optronics, October 7, 2006, ISBN 4-90212-10-0 T.A. Y. Fan, "Laser Beam Combining for High-Power, High-Radance Sources", IEEE Journal of Selected Topics in Quantum Electronics, Vol. 11, no. 3, May / June 2005, p567-577, 2005

  In conventional beam-coupled semiconductor laser light sources, wavelength locking is often performed using a volume Bragg diffraction grating. The volume Bragg diffraction grating reflects about 10% of light having a wavelength to be locked, and returns the reflected light to the semiconductor laser, and transmits light of other wavelengths. For this reason, the laser oscillation light may include light other than the lock wavelength, and unlock may occur.

  In order to solve the above problems, a beam-coupled semiconductor laser light source according to the present invention includes a plurality of semiconductor laser chips, a fast axis cylindrical collimator corresponding to the semiconductor laser chip, an imaging optical system, and a multimode optical fiber. Is further provided with a band-pass type dielectric multilayer filter and a partial reflecting mirror.

  According to the present invention, since the band-pass dielectric multilayer filter transmits only light of a specific wavelength, the output light is limited to the wavelength of the transmission band of the dielectric multilayer filter. For this reason, laser oscillation can be reliably locked in a narrow band.

1 is a schematic diagram showing the configuration of a beam-coupled semiconductor laser light source 10 according to a first embodiment of the present invention. It is the schematic which shows the structure of the dielectric multilayer filter 4 , and its characteristic. It is the schematic which shows another structure of the dielectric multilayer filter 4 , and its characteristic. It is the schematic which shows the beam combination type | mold semiconductor laser light source 40 of the 2nd Example of this invention. It is the schematic which shows the structure of the beam combination type | mold semiconductor laser light source 50 of the 3rd Example of this invention. It is the schematic which shows the structure of the beam combination type | mold semiconductor laser light source 60 of 4th Example of this invention. It is the schematic which shows the structure of the beam combination type | mold semiconductor laser light source 70 of 5th Example of this invention. It is the schematic which shows the structure of the beam combination type | mold semiconductor laser light source 80 of 6th Example of this invention. It is a top view which shows the structure of the beam coupling type | mold semiconductor laser light source 90 of 7th Example of this invention. It is a side view which shows the structure of the beam combination type | mold semiconductor laser light source 90 of 7th Example of this invention. It is the schematic which shows the structure of the wavelength multiplexing beam combination type | mold semiconductor laser light source 100 of 8th Example of this invention. 3 is a schematic diagram showing the structure of a three-port device 113 and a three-port device 130. FIG. It is the schematic which shows the structure of the dielectric multilayer filter 117 , and its characteristic. It is the schematic which shows the structure of the wavelength multiplexer 140 used in the 9th Example of this invention. It is the schematic which shows the structure of the wavelength multiplexing beam combining type | mold semiconductor laser light source 150 of 10th Example of this invention.

  Hereinafter, embodiments of a solid-state laser oscillator according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments. In the drawings, the same reference numerals are assigned to the same components.

[First embodiment]
FIG. 1 shows the configuration of a beam-coupled semiconductor laser light source 10 according to the first embodiment of the present invention. FIG. 1A is a view of the beam-coupled semiconductor laser light source 10 as viewed from the upper surface side. FIG. 1B is a side view of the beam-coupled semiconductor laser light source 10 . FIG. 1B corresponds to a view seen from the direction of arrow A in FIG.

A beam-coupled semiconductor laser light source 10 includes a plurality of semiconductor laser chips 1, a plurality of fast axis (FA) direction cylindrical collimators 2, one slow axis (SA) direction cylindrical collimator 3, and one A dielectric multilayer filter 4, one partial reflecting mirror 5, one FA direction imaging lens 6, one SA direction imaging lens 7, and one multimode optical fiber 8 are provided. The multimode optical fiber 8 is an optical fiber having a plurality of transverse modes.

  The FA direction imaging lens 6 and the SA direction imaging lens 7 are cylindrical lenses. An imaging optical system is formed by the FA direction imaging lens 6 and the SA direction imaging lens 7.

  Each semiconductor laser chip 1 is mounted on a submount 13. The plurality of submounts 13 are mounted on one mount 14 via insulating spacers 17. The multimode optical fiber 8 is attached to the mount 14 via an optical fiber support 9.

  The semiconductor laser chip 1 is, as one example, a gallium arsenide (GaAs) based semiconductor laser. As an example, the oscillation wavelength is in the 900 nm band. The semiconductor laser chip 1 includes a stripe 12. The stripe 12 is wide, and the transverse mode in the SA direction is multimode. The width of the stripe 12 is not particularly limited, and is 100 μm as an example. The semiconductor laser chip 1 is a so-called broad area laser.

  The submount 13 is made of a material having a thermal expansion coefficient substantially the same as that of GaAs and having a good thermal conductivity. As a material of the submount 13, for example, copper tungsten alloy (CuW), diamond particle-dispersed copper, or the like can be raised.

  The insulating spacer 17 is made of aluminum nitride (AlN). Alternatively, an insulating material thin film such as silicon nitride (Si3N4) may be formed on the submount 13 by vacuum deposition, sputtering, chemical vapor deposition, or the like.

  The laser light 15 from the semiconductor laser chip 1 is converted into parallel light with respect to the FA direction by the FA direction cylindrical collimator 2. The laser light 15 from the semiconductor laser chip 1 is converted into parallel light with respect to the SA direction by the SA direction cylindrical collimator 3.

  The light converted into parallel light enters the dielectric multilayer filter 4. The spectral characteristics of the dielectric multilayer filter change depending on the angle of incident light. However, since parallel light is incident on the dielectric multilayer filter 4, the spectral characteristics of the dielectric multilayer filter 4 are stabilized.

  The laser beam 15 from the semiconductor laser chip 1 has a small spread angle in the SA direction. For this reason, the SA-direction cylindrical collimator 3 can be omitted depending on the design of the optical system. However, in order to obtain high performance, it is preferable to provide the SA direction cylindrical collimator 3.

  The dielectric multilayer filter 4 is fixed to the mount 14 at an angle θ1. The angle θ1 is selected so as not to be perpendicular to the laser light 15 converted into parallel light. Only a specific wavelength of the laser beam 15 is transmitted by the dielectric multilayer filter 4. Light of other wavelengths becomes reflected light 16 and is emitted out of the incident optical path of the laser light 15 to the dielectric multilayer filter 4. The laser beam 15 that has passed through the dielectric multilayer filter 4 is partially reflected by the partial reflection mirror 5, and passes through the dielectric multilayer filter 4, the SA-direction cylindrical collimator 3, and the FA-direction cylindrical collimator 2, and the semiconductor laser chip 1. Return to

  By the above optical system, the end face 11 of the semiconductor laser chip 1 and the partial reflecting mirror 5 form a Fabry-Perot resonator. This configuration is a so-called external cavity type semiconductor laser, and wavelength locking occurs due to the wavelength selectivity of the dielectric multilayer filter 4. For this reason, the laser beam 15 has a specific wavelength (transmission wavelength of the dielectric multilayer filter 4).

  The wavelength-locked laser beam 15 is coupled to the multimode optical fiber 8 by the FA direction imaging lens 6 and the SA direction imaging lens 7.

  An imaging optical system that uses one spherical imaging lens instead of the FA direction imaging lens 6 and the SA direction imaging lens 7 can be formed.

FIG. 2A shows the configuration of the dielectric multilayer filter 4 . The dielectric multilayer filter 4 is provided with one cavity 26 on the transparent substrate 20. The cavity 26 has a structure in which a spacer layer 23 is sandwiched between two dielectric multilayer reflective layers 24 and 25. Such a structure and the filter characteristics of this structure are disclosed in detail in Non-Patent Document 1.

  The dielectric multilayer reflective layers 24 and 25 have a structure in which a low refractive index layer 21 having a thickness of λ / 4 and a high refractive index layer 22 having a thickness of λ / 4 are alternately stacked with respect to a certain wavelength λ. doing. The spacer layer 23 is composed of a low refractive index layer or a high refractive index layer having a thickness of nλ / 2. However, n is a natural number (a positive integer). However, FIG. 2 shows a case where n = 1.

The dielectric multilayer filter 4 is a band-pass filter that transmits only a specific wavelength band and reflects other wavelengths. That is, only a specific wavelength band in the incident light 30 is transmitted as transmitted light 31, and light of other wavelengths is reflected as reflected light 32. The dielectric multilayer filter 4 is a so-called band pass filter.

FIG. 2B shows the transmittance versus wavelength characteristic of the dielectric multilayer filter 4 . In the graph of FIG. 2B, the X axis is the wavelength and the Y axis is the transmittance. The dielectric multilayer filter 4 has a stop band 27, and has a narrow bandwidth transmission peak 28 in the stop band 27. When the incident light 30 is not perpendicular to the cavity 26, the transmission peak wavelength is shifted to the short wavelength side, for example, a transmission peak 29 shown in FIG. 2B.

Therefore, the wavelength transmitted through the dielectric multilayer filter 4 can be changed by changing the fixed angle θ1 shown in FIG. Using this characteristic, a product family of beam-coupled semiconductor laser light sources 10 having different lock wavelengths can be configured.

  For example, a solid laser crystal. Nd: YAG has an absorption wavelength at 885 nm. Another solid state laser crystal, Nd: YVO4, has an absorption wavelength at 880 nm. By changing the fixed angle θ1, the lock wavelength can be adjusted to 885 nm or 880 nm using the same dielectric multilayer filter 4.

  If the same dielectric multilayer filter 4 is attached to the mount 14 using supports with different fixed angles, the wavelength can be adjusted easily. This configuration has an advantage that the dielectric multilayer filter 4 which is a key part can be shared.

  The fixed angle θ1 can also be referred to as an inclination angle based on a direction perpendicular to the traveling direction of the laser light 15. The reason why the dielectric multilayer filter 4 is inclined with respect to the direction perpendicular to the traveling direction of the laser beam 15 is to prevent the reflected light from the dielectric multilayer filter 4 from returning to the semiconductor laser chip 1. is there.

  Since the dielectric multilayer filter 4 reflects light other than the transmitted light, if the dielectric multilayer filter 4 is mounted perpendicularly to the mount 14, the reflected light returns to the semiconductor laser chip 1 and is appropriate. Wavelength lock cannot be performed.

Strictly speaking, the transmission wavelength of the dielectric multilayer filter 4 is determined by the thickness of the spacer layer 23. Therefore, when a material having a low thermal expansion coefficient and a small temperature change in refractive index is used as the material of the spacer layer 23, the transmission wavelength of the dielectric multilayer filter 4 becomes stable. As a result, the lock wavelength of the beam-coupled semiconductor laser light source 10 is stabilized.

An example of a material having a low coefficient of thermal expansion and a small refractive index temperature change is silicon oxide (SiO 2). By using silicon oxide as the spacer layer 23, the beam-coupled semiconductor laser light source 10 with a stable lock wavelength can be realized.

FIG. 3A shows the configuration of the dielectric multilayer filter 4 when n is a larger natural number. The cavity 34 includes a spacer layer 33 instead of the spacer 23. The spacer layer 33 is thicker than the spacer layer 23 and has an order of n ≧ 2.

FIG. 3B shows the characteristics of the dielectric multilayer filter 4 configured as shown in FIG. A plurality of transmission peaks 35 occur in the stop band 27. Further, the transmission bandwidth of the transmission peak 35 is narrower than that of the transmission peak 28.

When the dielectric multilayer filter 4 having the configuration shown in FIG. 3 is applied to the configuration of FIG. 1, the oscillation wavelength of the laser light 15 can be locked in a narrower band. In addition, by using a semiconductor laser chip having different oscillation bands as the semiconductor laser chip 1, a specific peak can be selected from the plurality of transmission peaks 35. Therefore, the beam-coupled semiconductor laser light source 10 having different lock wavelengths can be realized by using the dielectric multilayer filter 4 having the same configuration.

The beam-coupled semiconductor laser light source 10 of this embodiment can be used as an excitation light source for a solid-state laser. It is particularly suitable for a fiber laser excitation light source. Moreover, it is suitable for an excitation light source for end face excitation of a rod-shaped solid-state laser. Further, it can be used for laser processing using a semiconductor laser beam coupled to an optical fiber.

[Second Example]
FIG. 4 shows a beam-coupled semiconductor laser light source 40 according to the second embodiment of the present invention. This embodiment is a modification of the beam-coupled semiconductor laser light source 10 . The beam-coupled semiconductor laser light source 40 is different from the beam-coupled semiconductor laser light source 10 in that the tilt direction of the dielectric multilayer filter 4 is changed.

In the beam-coupled semiconductor laser light source 40 , the dielectric multilayer filter 4 is inclined by a fixed angle θ2 in the component mounting surface direction of the mount 14. This fixed angle θ2 is an inclination angle with reference to a direction perpendicular to the traveling direction of the laser beam 15.

Also in the configuration of the beam-coupled semiconductor laser light source 40 , it is possible to prevent the reflected light from the dielectric multi-thin film filter 4 from being fed back to the semiconductor laser chip 1, so that a desired wavelength lock can be realized.

In the configuration of the beam-coupled semiconductor laser light source 40 , the wavelength at which the laser beam 15 is locked can be changed by changing the fixed angle θ2.

[Third embodiment]
FIG. 5 shows the configuration of a beam-coupled semiconductor laser light source 50 according to the third embodiment of the present invention. This embodiment is a modification of the beam-coupled semiconductor laser light source 10 . The beam-coupled semiconductor laser light source 50 is different from the beam-coupled semiconductor laser light source 10 in that a volume Bragg diffraction grating 51 is provided in place of the dielectric multilayer filter 4 and the partial reflector 5.

  The volume Bragg diffraction grating 51 has a structure in which a low refractive index layer having a thickness of λ / 4 and a high refractive index layer having a thickness of λ / 4 are alternately stacked with respect to a certain wavelength λ. However, the number of stacked layers is very large. This element is manufactured by performing interference exposure on glass having a characteristic that the refractive index changes by ultraviolet irradiation.

  This embodiment has an advantage that a simple configuration can be realized by reducing the number of optical elements required for wavelength locking. However, the locking wavelength cannot be changed by changing the fixed angle as in the case of the diffraction grating 4.

[Fourth embodiment]
FIG. 6 shows the configuration of a beam-coupled semiconductor laser light source 60 according to the fourth embodiment of the present invention. The beam-coupled semiconductor laser light source 60 includes two laser beam groups 61 and 62, one half-wave phase plate (polarization converter) 63, one polarization beam combiner 64, one dielectric multilayer filter 4, one One partial reflection mirror 5, one FA direction imaging lens 6, one SA direction imaging lens 7, and one multimode optical fiber 8 are provided.

  Each of the laser beam groups 61 and 62 includes a plurality of semiconductor laser chips 1, a plurality of FA direction cylindrical collimators 2, and one SA direction cylindrical collimator 3.

  The polarization direction of the laser light from the laser beam group 62 is converted by a ½ wavelength phase plate (polarization converter) 63 and guided to the polarization beam combiner 64. The laser beam from the laser beam group 61 and the laser beam from the laser beam group 62 are combined by the polarization beam combiner 64.

  The laser light from the polarization beam combiner 64 is wavelength-locked by the dielectric multilayer filter 4 and the partial reflection mirror 5. The principle of this wavelength lock is as described in the first embodiment.

  Laser light from the partial reflection mirror 5 is coupled to the multimode optical fiber 8 by the FA direction imaging lens 6 and the SA direction imaging lens 7.

In the beam-coupled semiconductor laser light source 60 , the laser light from the two laser beam groups is coupled to the multimode optical fiber 8 by the polarization beam combiner 64. It can be increased approximately twice.

Also in the beam-coupled semiconductor laser light source 60 , the arrangement of the dielectric multilayer filter 4 and the partial reflection mirror 5 as shown in FIG. 2 can be used. Also in the beam-coupled semiconductor laser light source 60 , as shown in FIG. 3, a volume Bragg diffraction grating 51 can be used instead of the dielectric multilayer filter 4 and the partial reflection mirror 5.

[Fifth Example]
FIG. 7 shows the configuration of a beam-coupled semiconductor laser light source 70 according to the fifth embodiment of the present invention. This embodiment is a modification of the beam-coupled semiconductor laser light source 10 . FIG. 7A is a view of the beam-coupled semiconductor laser light source 70 as seen from the upper surface side. FIG. 7B is a side view of the beam-coupled semiconductor laser light source 70 . FIG. 7C shows a laser beam profile in the section XX ′ in FIG. FIG. 7D shows a laser beam profile in the YY ′ cross section in FIG.

The beam-coupled semiconductor laser light source 70 includes a semiconductor laser array chip 71, an FA-direction cylindrical collimator 72, and an optical path conversion element 73 instead of the semiconductor laser chip 1 and the FA-direction cylindrical collimator 3.

  The semiconductor laser array chip 71 is attached to the submount 74. A plurality of submounts 74 are mounted on one mount 14 via insulating spacers 75.

  Laser light from the semiconductor laser array chip 71 is converted into parallel light by the FA-direction cylindrical collimator 72. The laser beam that has passed through the FA-direction cylindrical collimator 72 has a laser beam profile as shown in FIG.

  The optical path conversion element 73 has a function of rotating the angle of each laser beam by 90 °. The optical path conversion element 73 converts the laser beam profile as shown in FIG. 7C into a laser beam profile as shown in FIG. The optical path conversion element 73 can be constructed by the technique disclosed in Patent Document 1.

  The laser light from the optical path conversion element 73 is wavelength-locked by the dielectric multilayer filter 4 and the partial reflection mirror 5. The wavelength-locked laser beam is coupled to the multimode optical fiber 8 by the FA direction imaging lens 6 and the SA direction imaging lens 7.

Compared with the beam-coupled semiconductor laser light source 10 , the beam-coupled semiconductor laser light source 70 does not mount a large number of individual semiconductor laser chips 1 but uses a single semiconductor laser array chip 71 to package them. There is an advantage that manufacture becomes easy.

On the other hand, the beam-coupled semiconductor laser light source 10 has an advantage that the optical path conversion element 73 is not required as compared with the beam-coupled semiconductor laser light source 70 . The optical path conversion element 73 has a drawback that it causes a loss of light amount upon optical path conversion or restricts an effective aperture ratio. Such a problem does not occur in the beam-coupled semiconductor laser light source 10 .

The configuration shown in FIG. 4 can be applied to the beam-coupled semiconductor laser light source 70 . That is, the dielectric multilayer filter 4 can be mounted at a fixed angle θ2.

In the beam-coupled semiconductor laser light source 70 , a volume Bragg diffraction grating 51 can be provided instead of the dielectric multilayer filter 4 and the partial reflection mirror 5.

[Sixth embodiment]
FIG. 8 shows the configuration of a beam-coupled semiconductor laser light source 80 according to the sixth embodiment of the present invention. This embodiment is a modification of the beam-coupled semiconductor laser light source 60 shown in FIG. The beam-coupled semiconductor laser light source 80 is different from the beam-coupled semiconductor laser light source 60 in that laser beam groups 81 and 82 are provided instead of the laser beam groups 61 and 62.

Each of the laser beam groups 81 and 82 includes a semiconductor laser array chip 71, an FA direction cylindrical collimator 72, and an optical path conversion element 73. The configuration of the laser beam groups 81 and 82 conforms to the configuration of the beam-coupled semiconductor laser light source 70 shown in FIG.

Therefore, the configuration of the beam-coupled semiconductor laser light source 80 is a combination of the configuration of the beam-coupled semiconductor laser light source 60 and the configuration of the beam-coupled semiconductor laser light source 70 .

In the beam-coupled semiconductor laser light source 80 , the laser light from the two laser beam groups is coupled to the multimode optical fiber 8 by the polarization beam combiner 64. It can be increased approximately twice.

Compared with the beam-coupled semiconductor laser light source 60 , the beam-coupled semiconductor laser light source 80 is manufactured not by mounting a large number of individual semiconductor laser chips 1 but by using a semiconductor laser array chip 71 in a lump. There is an advantage that it becomes easy.

The configuration shown in FIG. 4 can be applied to the beam-coupled semiconductor laser light source 80 . That is, the dielectric multilayer filter 4 can be mounted at a fixed angle θ2.

In the beam-coupled semiconductor laser light source 80 , a volume Bragg diffraction grating 51 can be provided in place of the dielectric multilayer filter 4 and the partial reflection mirror 5.

[Seventh embodiment]
9 and 10 show the configuration of a beam-coupled semiconductor laser light source 90 according to the seventh embodiment of the present invention. FIG. 9 is a top view of the beam-coupled semiconductor laser light source 90 . FIG. 10 is a side view of the beam-coupled semiconductor laser light source 90 .

This embodiment is a modification of the beam-coupled semiconductor laser light source 60 shown in FIG. The beam-coupled semiconductor laser light source 90 includes laser beam groups 91 and 92 in place of the laser beam groups 61 and 62. In addition, the mount 95 has a platform-like structure, and includes platforms 96, 97, and 98.

  The semiconductor laser chip 1 is attached to the submount 93. A plurality of submounts 93 are mounted on one mount 95 via insulating spacers 94, respectively.

  Laser light from the semiconductor laser chip 1 belonging to the laser beam group 91 is guided to the polarization beam combiner 64 via the FA direction cylindrical collimator 2, the SA direction cylindrical collimator 3, and the reflecting mirror 88.

  Laser light from the semiconductor laser chip 1 belonging to the laser beam group 92 passes through the FA direction cylindrical collimator 2, the SA direction cylindrical collimator 3, the reflecting mirror 88, the reflecting mirror 89, and the half-wavelength phase plate 63, and is combined with the polarized beam. Guided to instrument 64.

  The laser beam from the laser beam group 91 and the laser beam from the laser beam group 92 are combined by the polarization beam combiner 64. Since the polarization beam combiner 64 couples the laser beams from the laser beam groups 91 and 92 to the multimode optical fiber 8, the laser beam power coupled to the multimode optical fiber 8 can be increased approximately twice. .

  A method for combining a plurality of laser beams using a platform-shaped mount 95 is based on the methods disclosed in Patent Documents 7 and 9.

In the beam-coupled light source disclosed in Patent Document 9, wavelength locking is performed using a volume Bragg diffraction grating. On the other hand, in the beam-coupled semiconductor laser light source 90 , wavelength locking is performed by the dielectric multilayer filter 4 and the partial reflection mirror 5.

As described above, the wavelength transmitted through the dielectric multilayer filter 4 can be changed by changing the fixed angle θ1 shown in FIG. By utilizing this characteristic, a product family of beam-coupled semiconductor laser light sources 90 having different lock wavelengths can be configured.

In the configuration using the volume Bragg diffraction grating, the lock wavelength cannot be changed in this way. In this respect, the beam-coupled semiconductor laser light source 90 is superior to the configuration of the prior art document 9.

In the beam-coupled semiconductor laser light source 90 , the arrangement of the dielectric multilayer filter 4 and the partial reflection mirror 5 as shown in FIG. 2 can be used.

[Eighth embodiment]
FIG. 11A shows the configuration of a wavelength-multiplexed beam-coupled semiconductor laser light source 100 according to the eighth embodiment of the present invention. The wavelength-multiplexed beam-coupled semiconductor laser light source 100 has a configuration that increases the intensity of laser light using a wavelength multiplexing technique. The beam-coupled semiconductor laser light source 100 can be used for laser processing by irradiating the workpiece 107 with the output laser beam 106. However, the application of the wavelength multiplexed beam coupled semiconductor laser light source 100 is not limited to laser processing.

The wavelength multiplexed beam coupled semiconductor laser light source 100 includes a plurality of single wavelength beam coupled semiconductor laser light sources 101a, 101b, 101c, 101d, and a wavelength multiplexer 103 based on a dielectric multilayer filter. The single wavelength beam coupled semiconductor laser light sources 101 a, 101 b, 101 c, and 101 d are connected by a multimode optical fiber 102 of the wavelength multiplexer 103.

  Single-wavelength beam-coupled semiconductor laser light sources 101a, 101b, 101c, and 101d generate laser beams having wavelengths λ1, λ2, λ3, and λ4, respectively.

  The laser light wavelength-multiplexed by the wavelength multiplexer 103 is sent to the output port 105 through the multimode optical fiber 104. The laser beam 106 from the output port 105 is irradiated to the workpiece 107.

  The lock wavelengths of the plurality of single-wavelength beam-coupled semiconductor laser light sources 101 are adjusted so as to oscillate laser beams having different wavelengths.

FIG. 11B shows the configuration of the single wavelength beam-coupled semiconductor laser light source 101 . The single wavelength beam coupled semiconductor laser light source 101 includes a plurality of broad area type semiconductor laser chips 108, a spatial multiplexer 109, a wavelength lock mechanism 110, a polarization multiplexer 111, and a multimode optical fiber (output optical fiber). 102. However, the polarization multiplexer 111 is not an essential element and can be omitted.

  The spatial multiplexer 109 has a function of coupling laser beams from a plurality of semiconductor laser chips 108 to a single multimode optical fiber 102 using a spatial optical system. The wavelength lock mechanism has a function of fixing the laser oscillation wavelength of the broad area type semiconductor laser chip 108 to a specific wavelength. The polarization multiplexer 111 has a function of combining a plurality of laser beams using a polarization converter and polarization beam combination.

Specific examples of the configuration of the single-wavelength beam-coupled semiconductor laser light source 101 include the above-described beam-coupled semiconductor laser light sources 10 , 40 , 50 , 60 , 70 , 80 , and 90 .

  In a wavelength multiplexing system for optical fiber communication, a distributed feedback semiconductor laser (DFB laser) is often used as a light source. It is difficult for the DFB laser to increase the laser light output. On the other hand, in the present embodiment, the output laser beam 106 can be increased in output because the wavelength-locked broad area type semiconductor laser is used.

Furthermore, in the single-wavelength beam-coupled semiconductor laser light source 101 used in this embodiment, laser light from a plurality of semiconductor laser chips 108 is used as a single multimode light by using a technique of spatial multiplexing and polarization multiplexing. Since it is coupled to the fiber, the output laser beam 106 can be increased in output.

Laser beams of different wavelengths from a plurality of single wavelength beam coupled semiconductor laser light sources 101 are coupled to a multimode optical fiber 104 by a wavelength multiplexer 103. The wavelength multiplexer 103 is based on a dielectric multilayer filter, but other principles such as a diffraction grating can also be used.

  The wavelength multiplexer based on the dielectric multilayer filter used in this embodiment is characterized in that the insertion loss is smaller than that of a wavelength multiplexer constructed using a diffraction grating. For this reason, it is suitable for applications that require high-power laser light. In addition, there is an advantage that high energy efficiency can be obtained.

FIG. 11C shows the configuration of the wavelength multiplexer 103 . The wavelength multiplexer 103 includes a plurality of three-port devices 113a, 113b, and 113c. The plurality of three-port devices 113 are connected in tandem to multiplex light of a plurality of wavelengths (for example, λ1, λ2, λ3, λ4). The wavelength multiplexer 103 can use an arbitrary number of wavelengths.

The number of three-port devices 113 of the wavelength multiplexer 103 is one less than the number of wavelengths. Since the wavelength multiplexer 103 performs only multiplexing and not demultiplexing, it can be configured in this way.

FIG. 12A shows the structure of the three-port device 113 . The three-port device 113 includes an optical fiber (reflection port) 114, an optical fiber (transmission port) 115, an optical fiber (common port) 116, a dielectric multilayer filter 117, a common lens 118, and a transmission port side lens 119. ing. The common lens 118 and the transmission port side lens 119 function as a collimating lens. The optical fibers 114, 115, and 116 are multimode optical fibers.

  As an example, the dielectric multilayer filter 117 transmits only light having a specific wavelength λ1, and reflects light having other wavelengths. The light 121 incident on the optical fiber (transmission port) 115 is light having this wavelength λ1. Light 121 from the optical fiber (transmission port) 115 is irradiated to the thin film filter 117 through the transmission port side lens 119. The transmitted light of wavelength λ1 is guided to the optical fiber (common port) 116 through the common lens 118.

  On the other hand, the light 120 incident on the optical fiber (reflection port) 114 is light having another wavelength λ2. The light 120 from the optical fiber (reflection port) 114 is applied to the thin film filter 117 through the common lens 118. The light 120 having the wavelength λ 2 is reflected by the thin film filter 117 and guided to the optical fiber (common port) 116 through the common lens 118.

Therefore, the light 121 having the wavelength λ 1 and the light 120 having the wavelength λ 2 are combined and guided to the optical fiber (common port) 116 as the combined light 122.
The angle formed between the normal line to the surface of the dielectric multilayer filter 117 and the light 121 is defined as θ3. As will be described later, the transmission wavelength λ1 of the dielectric multilayer filter 117 can be changed by changing this θ3.
The transmission wavelength can be changed by changing the parameter of the layer structure of the dielectric multilayer filter 117. The aforementioned three-port devices 113a, 113b, and 113c are configured to transmit wavelengths λ1, λ2, and λ3, respectively.
FIG. 12B shows the structure of the three-port device 130 having another structure. In the three-port device 130 , a coupling lens 131 is provided corresponding to the optical fiber (reflection port) 114, the optical fiber (transmission port) 115, and the optical fiber (common port) 116.

In the three-port device 130 , lenses 131, 119, and 132 that function as collimators are provided in the optical fibers 114, 115, and 116, respectively. Further, the optical axes of the lenses 131, 119, and 132 are made to coincide with the optical axes of the cores of the optical fibers 114, 115, and 116. For this reason, even if the value of θ3 is increased, it is not affected by the aberration of the lens.

FIG. 13A shows the configuration of the dielectric multilayer filter 117 . The dielectric multilayer filter 117 is provided with a plurality of cavities 26 on the transparent substrate 20. The plurality of cavities 26 are coupled through a coupling layer 133. The cavity 26 has the structure described in FIG. Such a multi-cavity dielectric multilayer filter and its characteristics are disclosed in detail in Non-Patent Document 1.

FIG. 13B shows the transmittance versus wavelength characteristic of the dielectric multilayer filter 117 . In the graph of FIG. 13B, the X axis is the wavelength and the Y axis is the transmittance. The dielectric multilayer filter 117 has a stop band 27, and a top flat transmission peak 134 in the stop band 27. In addition, the filter characteristic “cut off” is good. These properties are brought about by the multicavity structure.

When the value of θ3 changes, the transmission peak wavelength shifts to the short wavelength side, and becomes a transmission peak 135 shown in FIG. 13B, for example. In the structure shown in FIGS. 12A and 12B, the transmission peak wavelength of the dielectric multilayer filter 117 can be changed by changing θ3. By utilizing this characteristic, three-port devices having different transmission wavelengths can be made using the dielectric multilayer filter 117 having the same laminated film structure.

In such a configuration, a three-port device having a large number of different transmission wavelengths can be made using a small number of types of dielectric multilayer filters 117 . Therefore, the key parts can be shared.

In the three-port device shown in FIG. 13B, θ3 can be changed in a wide range, so that a three-port device having a wider variety of transmission wavelengths can be made using the common dielectric multilayer filter 117. it can.

[Ninth Example]
FIG. 14 shows the configuration of the wavelength multiplexer 140 . The wavelength multiplexed beam coupled semiconductor laser light source according to the ninth embodiment of the present invention uses this wavelength multiplexer 140 in place of the wavelength multiplexer 103 in the wavelength multiplexed beam coupled semiconductor laser light source 100 .

The wavelength multiplexer 140 includes a transparent substrate 141, dielectric multilayer filters 117a, 117b, and 117c, a plurality of lenses 131, and a plurality of multimode optical fibers 142. The principle of this wavelength multiplexer is as disclosed in Patent Document 12.

In the three-port device 113 , the light reflected by the dielectric multilayer filter 117 is coupled to the optical fiber 116 by the lens 118. For this reason, a coupling loss to the optical fiber 116 occurs. Since the wavelength multiplexer 103 shown in FIG. 11C uses three three-port devices 113a, 113b, and 113c, such a loss occurs three times.

On the other hand, in the wavelength multiplexer 140 , the light reflected by the dielectric multilayer filter 117 propagates through the transparent substrate 141 and is coupled to the optical fiber 142 (output port 143) via the lens 131. For this reason, the coupling loss to the optical fiber 142 occurs only once. Therefore, the wavelength multiplexer 140 has a smaller insertion loss than the wavelength multiplexer 103 .

From the above, in the wavelength multiplexed beam-coupled semiconductor laser light source 100 , the configuration using the wavelength multiplexer 140 has the advantages of high laser light output and high energy efficiency.

[Tenth embodiment]

FIG. 15 shows the configuration of a wavelength multiplexed beam coupled semiconductor laser light source 150 according to the tenth embodiment of the present invention. The wavelength multiplexed beam coupled semiconductor laser light source 150 is a modification of the wavelength multiplexed beam coupled semiconductor laser light source 100 .

The wavelength multiplexed beam coupled semiconductor laser light source 150 includes a plurality of single wavelength beam coupled semiconductor laser light sources 101a, 101b, 101c, 101d, 101e, 101f, 101g, 101h, a wavelength multiplexer 103a, and a wavelength multiplexer 103b. And a wavelength multiplexer 151. Although the wavelength multiplexers 103a and 103b have the same structure as the wavelength multiplexer 103, the transmission wavelengths of the provided three port devices are different.

  The wavelength multiplexer 103 a and the wavelength multiplexer 151 are connected by a multimode optical fiber 152. The wavelength multiplexer 103 b and the wavelength multiplexer 151 are connected by a multimode optical fiber 153. The wavelength multiplexer 151 and the output port 105 are connected by a multimode optical fiber 154. That is, the wavelength multiplexer 103a, the wavelength multiplexer 103b, and the wavelength multiplexer 151 are connected in a tree shape.

  Lights of wavelengths λ1, λ2, λ3, and λ4 from the single wavelength beam coupled semiconductor laser light sources 101a, 101b, 101c, and 101d are multiplexed by the wavelength multiplexer 103a. Further, light of wavelengths λ5, λ6, λ7, and λ8 from the single wavelength beam coupled semiconductor laser light sources 101e, 101f, 101g, and 101h are multiplexed by the wavelength multiplexer 103b.

The wavelength multiplexer 151 is a single three-port device, and has the same structure as the three-port device 113 shown in FIG. 12A or the three-port device 130 shown in FIG. . However, the wavelength multiplexer 151 includes a dielectric thin film filter having characteristics of transmitting wavelengths λ1, λ2, λ3, and λ4. Such a filter is known as a 4 skip 1 filter in optical fiber communication.

  The long multiplexer 151 multiplexes the light with wavelengths λ1, λ2, λ3, and λ4 from the wavelength multiplexer 140a and the light with wavelengths λ5, λ6, λ7, and λ8 from the wavelength multiplexer 103b. The eight wavelengths of light are combined and output from the output port 105 through the multimode optical fiber 154 and irradiated onto the workpiece 107.

If the wavelength multiplexer 103 shown in FIG. 11 is used for multiplexing light of eight wavelengths, seven three-port devices are required. The combined light is reflected up to seven times before being coupled to the output optical fiber.

  On the other hand, in the present embodiment, the light multiplexed by the wavelength multiplexer 103a is reflected at most three times. Thereafter, the light passes through the dielectric thin film filter of the wavelength multiplexer 151 once. In the wavelength multiplexer 103b, the combined light is reflected up to three times. Then, it is reflected once by the wavelength multiplexer 151. That is, it is reflected a total of four times.

The configuration of the wavelength multiplexed beam coupled semiconductor laser light source 150 performs multiplexing with a smaller number of reflections compared to the case of using a wavelength multiplexer that simply combines light of eight wavelengths. For this reason, the advantage that a multiplexing loss becomes small arises.

In addition, as the wavelength multiplexer 151, a wavelength multiplexer including three or more three-port devices may be used. In this case, light from a larger number of wavelength multiplexers 103 can be multiplexed. Further, a wavelength multiplexer 140 may be used instead of the wavelength multiplexer 103 . The wavelength multiplexer 140 can also be used as the wavelength multiplexer 151.

In the wavelength multiplexed beam coupled semiconductor laser light source 150, the wavelength multiplexers are connected in a two-stage tree shape, but a tree-like connection having a larger number of stages may be used.

[Technical features]
The technical features described here are summarized below.
(Regarding the features of FIG. 1)
[Technical Feature 1] In a beam-coupled semiconductor laser light source including a plurality of semiconductor laser chips, a fast-axis-direction cylindrical collimator corresponding to the semiconductor laser chips, an imaging optical system, and a multimode optical fiber,
A beam-coupled semiconductor laser light source, further comprising a band-pass dielectric multilayer filter and a partial reflection mirror.
[Technical Feature 2] In the beam-coupled semiconductor laser light source of Technical Feature 1,
Further, a beam-coupled semiconductor laser light source comprising a slow axis cylindrical collimator.
[Technical Feature 3] In the beam-coupled semiconductor laser light source of Technical Feature 1,
A beam-coupled semiconductor laser light source, wherein the imaging optical system comprises a fast-axis cylindrical imaging lens and a slow-axis cylindrical lens.
(Characteristics of FIGS. 1 and 4)
[Technical Feature 4] In the beam-coupled semiconductor laser light source of Technical Feature 1,
A beam-coupled semiconductor laser light source characterized in that a product family that generates laser oscillation of different wavelengths is constructed by changing the mounting angle of the dielectric multilayer filter.
(Regarding the features of FIG. 2)
[Technical Feature 5] In the beam-coupled semiconductor laser light source of Technical Feature 1,
The dielectric multilayer filter has a structure in which a spacer layer is sandwiched between two dielectric multilayer reflection layers, and the thickness of the spacer layer is nλ / 2.
Where λ is the transmission wavelength of the dielectric multilayer filter, and n is a natural number.
(Regarding the features of FIG. 3)
[Technical Feature 6] In the beam-coupled semiconductor laser light source of Technical Feature 5,
A beam-coupled semiconductor laser light source, wherein a value of n defining the thickness of the spacer layer is 2 or more.
(About the features of FIG. 5)
[Technical Feature 7] In a beam-coupled semiconductor laser light source including a plurality of semiconductor laser chips, a fast-axis-direction cylindrical collimator corresponding to the semiconductor laser chip, an imaging lens, and a multimode optical fiber,
A beam-coupled semiconductor laser light source comprising a volume Bragg diffraction grating.
(About the features of FIG. 6)
[Technical Feature 8] In a beam-coupled semiconductor laser light source that multiplexes two laser beam groups using a polarization beam combiner,
Each laser beam group includes a plurality of semiconductor laser chips, a fast axis cylindrical collimator corresponding to the semiconductor laser chips, and a mount.
The surface of the mount is flat
A beam-coupled semiconductor laser light source, characterized in that the semiconductor laser chip is arranged with respect to the mount so that the fast axis of laser light emitted from the semiconductor laser chip is horizontal to the mount surface.
[Technical Feature 9] In the beam-coupled semiconductor laser light source of Technical Feature 8,
Furthermore, a wavelength selection means is provided,
The wavelength selecting means is provided at a position after the laser beam is polarization-coupled.
[Technical Feature 10] In the beam-coupled semiconductor laser light source of Technical Feature 9,
The beam selection type semiconductor laser light source, wherein the wavelength selection means comprises a dielectric multilayer filter and a partial reflection mirror.
[Technical Feature 11] In the beam-coupled semiconductor laser light source of Technical Feature 9,
A beam-coupled semiconductor laser light source characterized in that the wavelength selection means comprises a volume Bragg diffraction grating.
(Regarding the features of FIG. 7)
[Technical Feature 12] Semiconductor laser array chip, fast axis cylindrical collimator,
In a beam-coupled semiconductor laser light source including an optical path conversion element, an imaging optical system, and a multimode optical fiber,
A beam-coupled semiconductor laser light source, characterized in that a wavelength selection means is provided between the optical path conversion element and the imaging optical system.
(Regarding the features of FIG. 8)
[Technical Feature 13] In a beam-coupled semiconductor laser light source that multiplexes two laser beam groups using a polarization beam combiner,
Each laser beam group includes a semiconductor laser array chip, a fast axis cylindrical collimator, and an optical path conversion element.
(Characteristics of FIGS. 9 and 10)
[Technical Feature 14] In a beam-coupled semiconductor laser light source that multiplexes two laser beam groups using a polarization beam combiner,
Each laser beam group includes a plurality of semiconductor laser chips, a fast-axis-direction cylindrical collimator corresponding to the semiconductor laser chips, wavelength selection means, and a step-shaped mount,
A beam-coupled semiconductor laser light source, wherein a dielectric multilayer filter and a partial reflector are provided at a position after the laser beam is polarization-coupled.
(About the features of FIG. 11)
[Technical Feature 15] In a wavelength-multiplexed beam-coupled semiconductor laser light source including a plurality of beam-coupled semiconductor laser light sources having different wavelengths and a wavelength multiplexer,
The beam-coupled semiconductor laser light source comprises a plurality of broad-area semiconductor laser chips, a spatial multiplexer, and a wavelength lock mechanism.
[Technical Feature 16] In the wavelength multiplexed beam-coupled semiconductor laser light source of Technical Feature 15,
2. The wavelength multiplexed beam coupled semiconductor laser light source, wherein the wavelength multiplexer includes a dielectric multilayer filter.
[Technical Feature 17] In the wavelength multiplexed beam-coupled semiconductor laser light source of Technical Feature 15,
A wavelength-multiplexed beam-coupled semiconductor laser light source characterized in that the transverse mode of the output laser light is a multimode.
(About features of FIG. 12)
[Technical Feature 18] In the wavelength-multiplexed beam-coupled semiconductor laser light source of Technical Feature 16,
2. The wavelength multiplexed beam coupled semiconductor laser light source, wherein the wavelength multiplexer includes a three-port device having three lenses.
(About the features of FIG. 13)
[Technical Feature 19] In the wavelength multiplexed beam-coupled semiconductor laser light source of Technical Feature 16,
2. The wavelength-multiplexed beam-coupled semiconductor laser light source, wherein the wavelength multiplexer includes a dielectric multilayer filter in which a plurality of cavities are coupled by a coupling layer.
(About the features of FIG. 14)
[Technical Feature 20] In the wavelength multiplexed beam-coupled semiconductor laser light source of Technical Feature 16,
The wavelength multiplexer includes a transparent substrate and a plurality of dielectric multilayer filters, and the dielectric multilayer filter is attached to the transparent substrate, and the light reflected by the dielectric multilayer filter is in the transparent substrate. Wavelength-multiplexed beam-coupled semiconductor laser light source characterized by propagating light.
(About the features of FIG. 15)
[Technical Feature 21] Technical Feature In a 15 wavelength multiplexed beam-coupled semiconductor laser light source,
2. The wavelength multiplexed beam-coupled semiconductor laser light source, wherein the wavelength multiplexer is constructed by connecting a plurality of wavelength multiplexers in a tree shape.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser chip 1, 2 ... FA direction cylindrical collimator, 3 ... SA direction cylindrical collimator, 4 ... Dielectric multilayer filter, 5 ... Partial reflection mirror, 6 ... FA direction imaging lens, 7 ... SA direction imaging lens 8 ... multimode optical fiber, 9 ... optical fiber support, 10 ... beam-coupled semiconductor laser light source, 11 ... end face of semiconductor laser chip 1, 12 ... stripe, 13 ... submount, 14 ... mount, 15 ... laser light, 16 ... Reflected light, 17 ... Insulating spacer, 20 ... Transparent substrate, 23 ... Spacer layer, 24, 25 ... Dielectric multilayer reflective layer, 26 ... Cavity, 27 ... Stop band, 28 ... Transmission peak, 29 ... Shifted transmission Peak, 30 ... incident light, 31 ... transmitted light, 32 ... reflected light, 33 ... spacer layer, 34 ... cavity, 35 ... transmission peak, 40 ... Beam coupled semiconductor laser light source, 50 ... Beam coupled semiconductor laser light source, 51 ... Volume Bragg diffraction grating, 60 ... Beam coupled semiconductor laser light source, 61, 62 ... Laser beam group, 63 ... 1/2 wavelength phase plate (polarized light) (Converter), 64 ... polarization beam combiner, 70 beam combined semiconductor laser light source, 71 ... semiconductor laser array chip, 72 ... FA direction cylindrical collimator, 73 ... optical path conversion element, 74 ... submount, 75 ... insulating spacer, 80 ... Beam-coupled semiconductor laser light source, 81, 82 ... Laser beam group, 88, 89 ... Reflector, beam-coupled semiconductor laser light source ... 90 , 91, 92 ... Laser beam group, 93 ... Submount, 94 ... Insulating spacer, 95 ... Holly stage-shaped mount, 96, 97, 98 ... Tar, 100- length multiplexed beam-coupled semiconductor laser Light source, 101 , 101a, 101b, 101c, 101d ... Single wavelength beam coupled semiconductor laser light source, 102 ... Multimode optical fiber, 103, 103a, 103b ... Wavelength multiplexer, 104 ... Multimode optical fiber, 105 ... Output Port 106 106 Output laser light 107 Workpiece 108 Broad area type semiconductor laser chip 109 Spatial multiplexer 110 Wavelength lock mechanism 111 Polarization multiplexer 113 113a 113b 113c ... Three-port device, 114 ... Optical fiber (reflection port), 115 ... Optical fiber (transmission port), 116 ... Optical fiber (common port), 117 ... Dielectric multilayer filter, 118 ... Common lens, 119 ... Transmission port Side lens 120 ... light with wavelength λ2, 121 ... light with wavelength λ1, 122 ... Wave light, 130 ... three-port device, 131 ... coupling lens, 133 ... bonding layer, 134 ... transmission peak, 135 ... shifted transmission peaks, 140 ... wavelength division multiplexer, 141 ... transparent substrate, 142 ... multimode optical fiber, 143 DESCRIPTION OF SYMBOLS ... Output port, 150 ... Wavelength multiplexed beam coupled semiconductor laser light source, 151 ... Wavelength multiplexer, 152, 153, 154 ... Multimode optical fiber.

Claims (7)

In a plurality of semiconductor laser chips, a fast axis axial collimator corresponding to the plurality of semiconductor laser chips, an imaging optical system, and a beam coupled semiconductor laser light source including a multimode optical fiber,
A beam-coupled semiconductor laser light source, further comprising a band-pass dielectric multilayer filter and a partial reflection mirror. The beam-coupled semiconductor laser light source according to claim 1,
Further, a beam-coupled semiconductor laser light source comprising a slow axis cylindrical collimator. The beam-coupled semiconductor laser light source according to claim 1,
A beam-coupled semiconductor laser light source, wherein the imaging optical system comprises a fast-axis cylindrical imaging lens and a slow-axis cylindrical imaging lens. The beam-coupled semiconductor laser light source according to claim 1,
A beam-coupled semiconductor laser light source characterized in that a product family that generates laser oscillation of different wavelengths is constructed by changing the mounting angle of the dielectric multilayer filter. The beam-coupled semiconductor laser light source according to claim 1,
The dielectric multilayer filter has a structure in which a spacer layer is sandwiched between two dielectric multilayer reflection layers, and the thickness of the spacer layer is nλ / 2.
Where λ is the transmission wavelength of the dielectric multilayer filter, and n is a natural number. The beam-coupled semiconductor laser light source according to claim 1,
A beam-coupled semiconductor laser light source, wherein a value of n defining the thickness of the spacer layer is 2 or more. In a plurality of semiconductor laser chips, a fast axis axial collimator corresponding to the plurality of semiconductor laser chips, an imaging optical system, and a beam coupled semiconductor laser light source including a multimode optical fiber,
A beam-coupled semiconductor laser light source comprising a volume Bragg diffraction grating.

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