JP2018066842A - Light guide device, method for manufacturing the same, and ld module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light guide device which attains an increased output of an output beam flux and a reduced size of the device.SOLUTION: The synthesis optical system COof a light guide device 10 includes: (1) a first mirror Mreflecting an input beam I; (2) a second mirror Mreflecting the input beam Ireflected by the first mirror M; (3) a third mirror Mreflecting the input beam I; and (4) a combiner Csynthesizing an output beam Oby transmitting the input beam Ireflected by the second mirror Mand reflecting the input beam Ireflected by the third mirror M.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light guide device that converts an input beam bundle composed of a plurality of input beams into an output beam bundle composed of a plurality of output beams. The present invention also relates to an LD module including such a light guide device and a method for manufacturing such a light guide device.

  In a fiber optical system such as a fiber amplifier or a fiber laser, a light guide device that guides a plurality of laser beams emitted from light sources such as a plurality of LDs (Laser Diodes) to one optical fiber is used. For example, FIG. 1 of Patent Document 1 shows a laser beam emitted from two LD chips (GaAlAs-LD) having an oscillation wavelength of 0.82 μm and two LD chips (InGaAsP) having an oscillation wavelength of 1.48 μm. -LD) and a light guide device for guiding a laser beam emitted from a DFB-type LD chip (InGaAsP-LD) to an erbium-doped optical fiber (part of an optical amplifier in Patent Document 1) Is described.

  In this optical amplifier, (1) two laser beams having different polarization planes emitted from two GaAlAs-LDs are combined into a first combined beam, and (2) polarization planes emitted from two InGaAsP-LDs. Two laser beams having different wavelengths are combined into a second combined beam, and (3) the first combined beam and the second combined beam having different wavelengths are combined into a third combined beam, and (4 ) Combine the wavelength of the laser beam emitted from the DFB type InGaAsP-LD with different wavelengths and the third combined beam into the fourth combined beam, and (5) add erbium using the objective lens. Lead to optical fiber.

JP-A-2-239237 (published on September 21, 1990)

  As shown in FIG. 1 of Patent Document 1, in this optical amplifier, the first direction is the direction along the optical axis of one GaAlAs-LD and the optical axis of the erbium-doped optical fiber. The optical axis of the other GaAlAs-LD is along a second direction approximately perpendicular to the first direction, and the optical axis of one InGaAsP-LD is along the first direction, while the other InGaAsP-LD is The optical axis is along the second direction. In this optical amplifier, the optical axis of the first combined beam is along the first direction, the optical axis of the second combined beam is along the second direction, and the light of the InGaAsP-LD that is a DFB type. The axis is along the second direction.

  In addition, each of the polarization beam splitter and the dichroic mirror that combines the two laser beams into one laser beam is disposed at the intersection of these two input beams, transmits one input beam, and transmits the other input beam. It combines into one output beam by reflecting at right angles. For example, a polarization beam splitter that polarizes and combines two laser beams emitted from two GaAlAs-LDs into a first combined beam is disposed at the intersection of these two laser beams, and one of the GaAlAs-LDs. By transmitting the laser beam from the first direction along the first direction and reflecting the laser beam from the other GaAlAs-LD along the first direction, the optical axis becomes the first along the first direction. The combined beam is combined by polarization. Hereinafter, the polarization beam splitter and the dichroic mirror are collectively referred to as a combiner.

  As described above, the optical amplifier illustrated in FIG. 1 of Patent Document 1 includes the five laser beams described above (two laser beams emitted from two GaAlAs-LDs and two lasers emitted from two InGaAsP-LDs. And a laser beam emitted from a DFB type InGaAsP-LD) can be combined into one output beam. However, this optical amplifier has a problem that it is difficult to increase the mounting density of each LD chip, or that it is difficult to reduce the size. This is because each LD chip is arranged on a specific surface (for example, the substrate surface) so that the optical axes of the LD chips do not intersect in an area other than the area where the combiner is arranged. This is because the LD chips cannot be arranged adjacent to each other so that the axis is along one optical axis.

  In light guide devices used in fiber optical systems such as fiber amplifiers and fiber lasers, it is strongly desired to increase the output beam or output beam bundle. Consider a case where the configuration of the optical amplifier described in Patent Document 1 is applied to a light guide device used in a fiber optical system such as a fiber amplifier or a fiber laser. In the light guide device, output of the output beam can be increased by increasing the number of LDs mounted on the light guide device. However, in order to increase the number of LDs mounted on the light guide device, it is required to dispose further LDs so as not to be adjacent to each other, resulting in an increase in the size of the light guide device.

  As described above, when the configuration of the optical amplifier described in Patent Document 1 is applied to a light guide device used in a fiber optical system such as a fiber amplifier or a fiber laser, the output light bundle can be increased in power, and the light guide device. It is difficult to achieve both downsizing.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a light guide device that converts an input beam bundle composed of input beams emitted from a plurality of light sources into an output beam bundle and guides it to an optical fiber. An object of the present invention is to provide a light guide device that achieves both high output beam bundle output and miniaturization of the light guide device.

In order to solve the above-described problem, a light guide device according to one embodiment of the present invention includes 2n (n is a natural number) input beams I ₁ , I _{2 ,.} In the light guide device that converts the input beam bundle into an output beam bundle composed of n output beams O ₁ , O ₂ ,... On with the optical axis along the second axis, two input beams I _2k−1 , _{I 2k (k = 1,2, ...} n) a synthetic optical system CO _k for synthesizing the output beam _{O k} from the first reflecting in the direction along the third axis (1) input beam _{I 2k-1} A mirror M _k1 , (2) a second mirror M _k2 that reflects the input beam I _2k-1 reflected by the first mirror M _k1 in a direction along the second axis, and (3) an input beam I _2k that is a third mirror _{M k3} for reflecting in the direction along the 3 axis, is reflected at (4) a second mirror _{M k2} Thereby transmitting a force beam _{I 2k-1,} by reflecting in the direction along the input beam _{I 2k} reflected by the third mirror _{M k3} to the second shaft, and the combiner _{C k} for synthesizing the output beam _{O k,} and a combining optical system CO _k including.

According to the above configuration, the light guide device converts an input beam bundle composed of _2n (n is a natural number) input beams I ₁ , I ₂ ,..., I _2n into n output beams O ₁ , O _2. , ..., after converted into an output beam bundle consisting of O _n, it is possible to direct the output beam bundle to the optical fiber. Therefore, this light guide device can achieve high output beam bundle output.

Further, the combiner of the light guide device has an input beam bundle composed of _2n (n is a natural number) input beams I ₁ , I ₂ ,..., I _2n along the first axis, and the optical axis is the second. It can be converted into an output beam bundle consisting of _n output beams O ₁ , O ₂ ,. As described above, the optical axes of the input beams I ₁ , I ₂ ,..., I _2n are all along the first axis that is one axis, and the output beams O ₁ , O _{2 ,.} The optical axes are along the second axis, which is one axis. Therefore, input beams _{I 1, I 2, ...,} I 2n and the output beam _{O 1,} O 2, ..., when placing the _{O n,} input beam _{I 1,} I 2, _..., not intersect each _{I 2n} as it is not necessary to consider, and the output beam O _1, O 2, _..., each O _n is not necessary to consider so as not to cross. Therefore, since each of the optical axes of the input beams I ₁ , I ₂ ,..., I _2n can be arranged in parallel, compared with a conventional light guide device (for example, an optical amplifier described in Patent Document 1). It can be downsized.

  As described above, the light guide device can achieve both high output beam bundle output and miniaturization of the light guide device.

Further, according to the above configuration, the light guide device, when converting from the input beam bundle in the output beam bundles, output beam O _1, O 2, _..., half the number of O _n from the 2n into n Let Therefore, this light guide device has a secondary effect that the width of the output beam bundle can be reduced as compared with the case where the output beam bundle is constituted by 2n output beams.

Further, according to the above configuration, the light guide device includes an input beam bundle composed of the input beams I ₁ , I ₂ ,..., I _2n, and the n output beams O ₁ , Each of the first mirror M _k1 , the second mirror M _k2 , the third mirror M _k3 , and the combiner C _k constituting the composite optical system CO _k is converted into an output beam bundle composed of O _{2 ,.} by adjusting the output beam O _1, O 2, _..., the optical axis of the O _n can be adjusted along the second axis.

  On the other hand, in the conventional light guide device, one combiner is used to convert two laser beams (corresponding to input beams) into one laser beam (corresponding to output beams). Therefore, in this optical amplifier, the combiner can only be adjusted to adjust the optical axis of the output beam.

Accordingly, the light guide device, in comparison with conventional light device, the output beam O _1, O 2, _..., a high degree of freedom in the case of adjusting the optical axis of the O _n, as a result, facilitating the adjustment There is a secondary effect that can be performed.

In the light guide device according to an aspect of the present invention, n is a natural number of 2 or more, and each of the two input beams I _2k-1 and I _2k incident on the composite optical system CO _k has a wavelength of And the planes of polarization are aligned, and the combining optical system CO _k further includes a polarization rotation element disposed in front of the first mirror M _k1 or in front of the third mirror M _k3. The combiner C _k is preferably a polarization-dependent beam combiner.

According to the above configuration, the light guide device has a wavelength are the same, and by combining the output beam O _k from the input beam I _2k-1, I _2k plane of polarization are aligned, wavelength single A simple output beam bundle can be guided to the optical fiber. Further, since there is no upper limit for the number of input beams I ₁ , I ₂ ,..., I _2n , the output of the output beam bundle can be easily increased.

  On the other hand, in the conventional light guide device, when an output beam having a single wavelength (output beam bundle) is to be obtained, it is difficult to increase the output of the output beam. Because, when the output of each input beam is the same, (1) the output beam output depends on the number of input beams, and (2) the number of input beams that can be used in this light guide device is limited to 2 This is because. In order to use a larger number of input beams in this light guide device, a dichroic mirror must be used as a combiner. In this case, an output beam having a single wavelength cannot be obtained.

  Therefore, the present light guide device can guide the output beam bundle whose distribution width of the spectrum of the output beam bundle is narrower than that of the conventional light guide device to the optical fiber, and easily increase the output beam bundle output. Can be planned.

In the light guide device according to an aspect of the present invention, each of the two input beams I _2k-1 and I _2k incident on the composite optical system CO _k has a different wavelength, and the combiner C _k A dichroic mirror may be used.

When the light guide device according to one aspect of the present invention adopts a configuration in which the wavelengths of the two input beams I _2k-1 and I _2k are different from each other, the light guide device employs a dichroic mirror as the combiner C _k. You can also.

In the light guide device according to an aspect of the present invention, each of the first mirror M _k1 and the third mirror M _k3 is placed on a specific plane stretched by the first axis and the second axis. The second mirror M _k2 is placed on the first mirror M _k1 , and the combiner C _k is placed on the third mirror M _k3. The optical axes of the two input beams I _2k-1 and I _2k are arranged in a plane parallel to the specific plane, and the reflection that constitutes the first mirror M _k1 with respect to the combined optical system CO _k. the first reflecting surface _{P k1} is a surface, the second mirror _{M k2} is a reflective surface constituting the second reflecting surface _{P k2,} the third third reflecting surface _{P k3} a reflecting surface constituting a mirror _{M k3,} and, each of the synthetic surface _{P kC} constituting the combiner _{C k} , The optical axis of the output beam O _k is adjusted to match the second shaft, it is preferable.

  According to said structure, the output beam bundle which can be converged with a sufficient precision can be obtained by combining with the convergence optical system comprised by the convex lens.

In the light guide device according to an aspect of the present invention, each of the first reflection surface P _k1 and the third reflection surface P _k3 has a normal vector extending from the first axis and the third axis. The angle between the normal vector and the third axis is 45 °, and each of the second reflecting surface P _k2 and the composite surface P _kC is a normal line. It is preferable that the vector is located in a plane extending by the third axis and the second axis, and an angle formed by the normal vector and the third axis is 45 °.

  According to the above configuration, it is possible to easily obtain an output beam bundle that can be converged with high accuracy by combining with a converging optical system including a convex lens.

In the light guide device according to an aspect of the present invention, the first mirror M _k1 and the third mirror M _k3 may be integrally formed.

According to said structure, compared with the case where the 1st mirror _Mk1 and the 3rd mirror _Mk3 are formed in the different body, the optical axis adjustment in a synthetic | combination optical system can be performed easily.

In the light guide device according to an aspect of the present invention, the optical axes of the input beams I ₁ , I ₂ ,..., I _2n are arranged at equal intervals, and the combined optical system CO _k the first reflecting surface _{P k1,} the second reflecting surface _{P k2,} the third reflecting surface _{P k3,} and combining surface _{P kC,} the output beam _{O 1,} O 2, ..., of each of the _{O n} optical axis of the specific It is preferable that they are adjusted so as to be arranged at equal intervals in a plane parallel to the plane.
The light guide device according to claim 4, wherein the light guide device is a light guide device.

  According to said structure, the precision at the time of converging an output beam bundle can be further improved combining with the convergence optical system comprised by the convex lens etc. FIG.

In order to solve the above problems, an LD module according to an aspect of the present invention includes a light guide device according to any one aspect described above, and each of the input beams I ₁ , I _{2 ,.} LD chip _{LD 1,} LD 2 that emits, ..., and _{LD 2n,} the converted by the light guiding device output beam _{O 1,} O 2, ..., and an optical fiber coupled to _{O n,} the LD chip _LD 1, LD _2, ..., a inserted collimating optical system between the _{LD 2n} and the combining optical system CO _k, F-axis collimating lens _{FC 1, FC 2, ...,} and _{FC 2n,} the F-axis collimating lens FC _{1, FC} 2, ..., S-axis collimating lens _SC 1 which is disposed downstream of the _{FC 2n,} SC 2, ..., and _{SC 2n,} a collimating optical system configured by, said optical fiber and the light guide device A inserted condenser lens system during comprises a F-axis converging lens, and the S-axis converging lens arranged downstream of the F-axis converging lens, a converging optical system configured by the.

  According to said structure, there exists an effect similar to the light guide device which concerns on 1 aspect of this invention.

In addition, since this LD module can obtain an output beam bundle having a narrow width as compared with the case where the output beam bundle is composed of _2n output beams, the coupling efficiency between the light guide device and the optical fiber is improved. Can be improved, aberration caused by the F-axis converging lens constituting the converging optical system can be suppressed, or the distance from the F-axis converging lens to the optical fiber can be shortened.

The LD module according to an aspect of the present invention further includes a substrate on which the first mirror M _k1 and the third mirror M _k3 constituting the light guide device are mounted, and the LD chip LD1, LD2, ..., each LD _2n, each active layer is arranged along the said surface of the substrate, it is preferable.

According to the above configuration, LD chip _{LD 1, LD 2, ...,} and the active layer of the _{LD 2n,} the area of the region and the substrate are in contact can be maximized. Therefore, the LD chips LD ₁ , LD ₂ ,..., LD _2n can be efficiently cooled.

In order to solve the above problems, the manufacturing method according to an embodiment of the present invention is a manufacturing method for manufacturing a light guiding device according to any one aspect as described above, for each of the combining optical system CO _k, wherein The directions of the first mirror M _k1 , the second mirror M _k2 , the third mirror M _k3 , and the combiner C _k are as follows: (1) The output beam _Ok is synthesized from the input beams I _2k−1 and I _2k. as to, and, (2) so that the optical axis of the output beam O _k coincides with the second axis includes the step of adjusting.

  According to said structure, there exists an effect similar to the light guide device which concerns on 1 aspect of this invention.

  The present invention relates to a light guide device that converts an input beam bundle composed of input beams emitted from a plurality of light sources into an output beam bundle and guides it to an optical fiber. Both can be achieved.

It is a perspective view of LD module concerning Embodiment 1 of the present invention. FIG. 2 is a plan view of the LD module shown in FIG. 1. It is a perspective view of the unit optical system with which the LD module shown in FIG. 1 is provided. (A) is a perspective view of the 1st-3rd mirror and polarization-dependent beam combiner which comprise the synthetic | combination optical system contained in the unit optical system shown in FIG. (B) is a perspective view which shows the beam profile of an input beam and an output beam. It is a flowchart of the manufacturing method of LD module shown in FIG. It is sectional drawing of the output beam bundle after implementing the manufacturing method shown in FIG. It is a perspective view of the unit optical system with which the LD module which concerns on Embodiment 2 of this invention is provided.

[First Embodiment]
The LD module 1 according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of the LD module 1. FIG. 2 is a plan view of the LD module 1. FIG. 3 is a perspective view of the unit optical system Sk provided in the LD module 1. FIG. 4A is a perspective view of the first to third mirrors M _{k1 to} M _k3 and the polarization-dependent beam combiner C _k constituting the synthesis optical system CO _k included in the unit optical system Sk. is there. FIG. 4B is a perspective view showing beam profiles of the input beams I _2k−1 and I _2k and the output beam Ok.

As shown in FIGS. 1 to 2, the LD module 1 includes a substrate B, a light guide device 10, and a collimating optical system in addition to _2n LD chips LD ₁ , LD ₂ ,..., LD _2n and an optical fiber OF. 20 and a converging optical system 30.

In the following, a direction along the normal line of the surface BS of the substrate B (parallel in the present embodiment) and from the back surface of the substrate B toward the surface BS is defined as a positive z-axis direction. The surface BS is a surface on the side where the light guide device 10, the collimating optical system 20, and the converging optical system 30 are placed among the two surfaces constituting the substrate B. A direction along the optical axis of the laser beam (input beam) emitted from each of the LD chips LD ₁ , LD ₂ ,..., LD _2n along the surface BS (parallel in the present embodiment) The propagation direction of the beam is the x-axis positive direction. A direction along the surface BS and perpendicular to the x-axis is taken as a y-axis. The positive y-axis direction is determined so that each of the above-described x-axis, y-axis, and z-axis is a right-handed coordinate axis. Each of the x axis, the y axis, and the z axis corresponds to the first axis, the second axis, and the third axis recited in the claims.

(LD chip)
LD module 1, LD chip _{LD 1,} LD ₂ of 2n (n is a natural _{number), ..., LD 2k-1} , LD 2k, ..., LD 2n-1, LD 2n light each laser beam emitted from the Couple to fiber OF. Here, k is k = 1, 2,..., N. In the following, the LD chips LD ₁ , LD ₂ ,..., LD _2k−1 , LD _2k ,..., LD _2n−1 , LD _2n are generalized and described as LD chips LD _2k−1 , LD _2k . This generalization method is the same for other members.

  In the present embodiment, the number 2n of LD chips included in the LD module 1 is twelve. However, the number 2n of LD chips is not limited to this. That is, the number 2n of LD chips included in the LD module 1 can be arbitrarily selected from an even number of 2 or more.

In the present embodiment, the LD chips LD ₁ , LD ₂ ,..., LD _2k−1 , LD _2k ,..., LD _2n−1 , LD _2n are configured similarly. Therefore, LD chips LD1, LD2,..., _LD2k-1 , _LD2k ,..., _LD2n-1 , _LD2n respectively emit input beams I1, I2, ..., _I2k-1 , _I2k,. The wavelengths of I _2n-1 and I _2n are the same.

Input beams I ₁ , I ₂ ,..., I _2k−1 , I _2k ,..., I _2n−1 , I _2n , that is, the optical axes of the input beams I _2k−1 , I _2k are in the x-axis direction and y-axis direction. LD _2k-1 and LD _2k are placed on the surface BS of the substrate B so as to be arranged at equal intervals along a specific plane along the line. The surface BS is a specific plane recited in the claims, and in the present embodiment, is parallel to the xy plane.

Each of the LD chips LD _2k-1 and LD _2k includes an active layer arranged in a single plane along the surface BS. In other words, the active layers of the LD chips LD _2k-1 and LD _2k are arranged in a single plane having the same height from the surface BS.

When viewed from the x-axis positive direction side, the shape of each of the active layers of the LD chips LD _2k-1 and LD _2k is the direction along the y-axis direction and the direction along the z-axis direction. Is a substantially rectangular shape in the short direction. Each of the input beams I ₁ , I ₂ ,..., I _2n emitted from the active layer has a major axis in the direction along the y-axis direction and the z-axis immediately after being emitted. It has an elliptical beam profile whose direction is the minor axis. Then, such an input beam _{I 1,} I 2, _..., along the _{I 2n,} the output beam _O 1 converted by the light guiding device _{10, O 2, ..., O} n , the long axis is in the z-axis direction, The minor axis has an elliptical beam profile along the x-axis direction.

In the present embodiment, each of the LD chips LD _2k-1 and LD _2k is configured similarly. That is, each of the LD chips LD _2k-1 and LD _2k emits input beams I _2k-1 and I _2k having the same wavelength and the same polarization plane.

(Light guide device 10)
Next, the light guide device will be described. The light guide device 10 converts the input beam bundle IB composed of the input beams I _2k-1 and I _2k emitted from the LD chips LD _2k-1 and LD _2k into an output beam bundle OB composed of the output beam Ok. As described above, the optical axes of the input beams I _2k-1 and I _2k are along the x-axis direction (parallel in this embodiment). Further, as will be described later, the output beam OB is along the y-axis (parallel in the present embodiment).

The light guide device 10 includes n synthetic optical systems CO _k (k = 1, 2,..., N) placed on the surface BS of the substrate B. The synthetic optical system CO _{k + 1} is disposed on the surface BS at a position where the synthetic optical system CO _k is translated in the positive x-axis direction and in the positive y-axis direction.

As shown in FIG. 3, the combining optical system CO _k includes a first mirror M _k1 , a second mirror M _k2 , a third mirror M _k3, and a polarization-dependent beam combiner that is a combiner according to the claims. (PBC) C _k and polarization rotation element PR _k are included. In the following, described as PBCC _k to a polarization dependent beam combiner _{C k.}

The first mirror M _k1 has a first reflecting surface P _k1 that reflects the input beam I _2k-1 in a direction along the z-axis. The first reflecting surface P _k1 is obtained by forming a reflecting film (for example, an aluminum thin film) on a polished slope of an optical member made of glass (for example, quartz glass).

The second mirror M _k2 has a second reflecting surface P _k2 that reflects the input beam I _2k-1 reflected by the first mirror M _{k1 in the} direction along the y-axis. The second mirror M _k2 is configured by an optical member (for example, a prism) made of glass (for example, quartz glass), and the bottom surface along the xy plane and the side surface along the zx plane both have the input beam I _{2k−. 1} is transmitted. The second reflecting surface P _k2 is obtained by forming a reflecting film (for example, an aluminum thin film) on a polished slope that intersects both the bottom surface and the side surface.

The polarization rotation element PR _k is disposed in front of the third mirror M _k3 and rotates the polarization plane of the input beam I _2k by 90 °. Accordingly, the polarization plane of the input beam I _2k incident on the third mirror M _k3 is rotated by 90 ° compared to the input beam I _2k−1 incident on the first mirror M _k1 .

The third mirror M _k3 has a third reflecting surface P _k3 that reflects the input beam I _2k in the direction along the z-axis. PBCC _k is configured to transmit the input beam _{I 2k-1} reflected by the second mirror _{M k2,} the input beam _{I 2k} reflected by the third mirror _{M k3} is reflected in the direction along the y-axis output having a PBCC _k for synthesizing the beam _{O k.} The composite plane P _kC of PBCC _k transmits light whose polarization plane is parallel to a predetermined direction, and reflects light whose polarization plane is orthogonal to the predetermined direction. In this embodiment, the synthetic surface _{P kC} the input beam is transmitted through the _{I 2k-1,} reflects the input beam _{I 2k} which the polarization plane is orthogonal to the polarization plane of the input beam _{I 2k-1.}

Note that the polarization rotator PR _k may be arranged not in the preceding stage of the third mirror M _k3 but in the preceding stage of the first mirror M _k1 . However, even in that case, the synthesis plane P _kC is configured to transmit the input beam I _2k-1 and reflect the input beam I _2k .

For the combining optical system CO _k , each of the first reflecting surface P _k1 , the second reflecting surface P _k2 , the third reflecting surface P _k3 , and the combining surface P _kC is the light of each of the output beams O1, O2,. The optical axis may be adjusted so that the axes are arranged at equal intervals in a plane parallel to a specific plane. The optical axis adjustment for this synthetic optical system CO _k will be described later with reference to FIG.

(Collimating optics)
The collimating optical system 20 is inserted between the LD chips LD _2k-1 and LD _2k and the combining optical system CO _k . The collimating optical system 20 includes (1) F-axis collimating lenses FC _2k-1 and FC _2k arranged at the _subsequent stage of the LD chips LD _2k-1 and LD _2k , and (2) F-axis collimating lenses FC _2k-1 and FC. _And S-axis collimating lenses SC _2k-1 and SC _2k arranged at the _subsequent stage of _2k and the preceding stage of the synthesis optical system CO _k .

The F-axis collimating lenses FC _2k-1 and FC _2k collimate the spread in the F-axis direction of the input beams I _2k-1 and I _2k emitted from the LD chips LD _2k-1 and LD _2k . The S-axis collimating lenses SC _2k-1 and SC _2k collimate the spread in the S-axis direction of the input beams I _2k-1 and I _2k emitted from the LD chips LD _2k-1 and LD _2k . The input beams I _2k-1 and I _2k after passing through the F-axis collimating lenses FC _2k-1 and FC _2k and the S-axis collimating lenses SC _2k-1 and SC _2k have a beam spot shape and size regardless of the propagation distance. This is a so-called collimated beam that is kept constant. Note that when the input beams I _2k-1 and I _2k emitted from the LD chips LD _2k-1 and LD _2k are sufficiently small in the S-axis direction, the S-axis collimating lenses SC _2k-1 and SC _2k are omitted. It doesn't matter.

(Convergence optics)
The converging optical system 30 is a condensing lens system inserted between the light guide device 10 and the optical fiber OP. The converging optical system 30 includes (1) an F-axis converging lens FL disposed downstream of the combining optical system CO _k , and (2) an S-axis disposed downstream of the F-axis converging lens FL and upstream of the optical fiber OP. And an axis converging lens SL. F-axis converging lens FL, the output of each output beam O _k that constitute the beam bundle (becomes preferably 0) z-axis beam diameter is minimized at the incident end face of the optical fiber OF in focusing as. Also, the S-axis converging lens SL, each output beam O _k constituting the output beam bundles, beam spacing becomes minimum at the incident end face of the optical fiber OF (preferably becomes 0) manner, and, x-axis direction Of the optical fiber OF is converged so as to be minimized (preferably 0) at the incident end face of the optical fiber OF.

(Configuration of unit optical system)
LD module 1 is obtained by repeating placing unit optical system S _k shown in FIG. As shown in FIG. 3, the unit optical system _Sk includes the above-described LD chips LD _2k-1 and LD _2k , F-axis collimating lenses FC _2k-1 and FC _2k , and S-axis collimating lenses SC _2k-1 and SC. and _2k, composed of a composite optical system CO _k.

Each of the first mirror M _k1 and the third mirror M _k3 is placed on a specific plane stretched by the x axis and the y axis, in this embodiment, the surface BS of the substrate B. The second mirror M _k2 is placed on the first mirror M _k1 , and the PBCC _k is placed on the third mirror M _k3 . The first mirror M _k1 and the third mirror M _k3 may be integrally formed.

Further, as described above, the LD chips LD _2k-1 and LD _2k are arranged such that the active layer is along the surface BS of the substrate B. Therefore, the optical axes of the two input beams I _2k-1 and I _2k are aligned in a plane parallel to the surface BS of the substrate B.

Synthesis optical system CO _k, the first reflecting surface _{P k1} is a reflecting surface that constitutes the first mirror _{M k1,} the second reflecting surface _{P k2} is a reflecting surface that constitutes the second mirror _{M k2,} a third mirror _{M k3} third reflecting surface P _k3 and _a reflecting surface that constitutes the, each combining surface P _kC constituting the PBCC _k, the optical axis of the output beam O _k is adjusted to be parallel to the y-axis.

LD chips LD _2k-1 and LD _2k , F-axis collimating lenses FC _2k-1 and FC _2k , S-axis collimating lenses SC _2k-1 and SC _2k , first mirror M _k1 , third mirror M _k3 , and F-axis condensing The lens FL and the S-axis condenser lens SL are both placed on the substrate B directly or via a mount (not shown), and are fixed (for example, adhesively fixed) when completed.

Figure. 4 (a), the reflecting surface _{P k1} of the first mirror _{M k1} constituting the combining optical system CO _k, reflecting surface _{P k2} of the second mirror _{M k2,} reflective surface _{P k3} of the third mirror _{M k3} and, , PBCC _k composite surface P _{kC is} shown.

Each of the first reflecting surface P _k1 and the third reflecting surface P _k3 is located in a plane in which the respective normal vectors extend from the x axis and the z axis, and the normal vector and the z axis are formed. The angle is configured to be 45 °.

Each of the second reflecting surface P _k2 and the composite surface P _kC is located in a plane in which the respective normal vectors extend from the y axis and the z axis, and an angle formed between the normal vector and the z axis is It is comprised so that it may become 45 degrees.

As described above, the optical axis of the incident beam I _2k-1 is along the x-axis (in this embodiment, parallel). Therefore, the incident beam I _2k-1 propagates in parallel to the x axis on a plane parallel to the plane extending by the x axis and the y axis (a plane parallel to the surface BS of the substrate B), and is reflected by the first mirror M _k1 . Incident on the surface P _k1 . The incident beam I _2k-1 is reflected by the reflecting surface P _k1 and enters the second mirror M _k2 while changing the optical path in a direction parallel to the z axis. The incident beam I _2k-1 is reflected by the reflecting surface P _k2 of the second mirror M _k2 and enters the combined surface P _kC of PBCC _k by changing the optical path in a direction parallel to the y axis. The synthesis plane P _kC transmits the incident beam I _2k−1 .

As described above, the optical axis of the incident beam I _2k is along the x-axis (in this embodiment, parallel). Therefore, the incident beam I _2k propagates in parallel with the x axis on a plane parallel to the plane extending by the x axis and the y axis (a plane parallel to the surface BS of the substrate B), and the reflecting surface P of the third mirror M _k3. Incident at _k3 . The incident beam I _2k is reflected by the reflecting surface P _k3 and enters the combined surface P _kC of PBCC _k while changing the optical path in a direction parallel to the z axis. The synthesis plane P _kC reflects the incident beam I _2k . The synthetic surface _{P kC} is the transmitted incident beam _{I 2k-1} and the reflected incident beam by combining the _{I 2k} outputs an output beam _{O k.} The optical axis of the output beam O _k is (are parallel in the present embodiment) which is along the y-axis.

Thus combining optical system CO _k is constituted by the output beam O _k which the optical axis optical axis input beam I _2k-1, I input beams IB constituted by _2k along the x-axis is along the y-axis The output beam bundle OB can be converted. Therefore, input beams _{I 1, I 2, ...,} I 2n and the output beam _{O 1,} O 2, ..., when placing the _{O n,} input beam _{I 1,} I 2, _..., not intersect each _{I 2n} as it is not necessary to consider, and the output beam O _1, O 2, _..., each O _n is not necessary to consider so as not to cross.

Therefore, in the light guide device 10, the optical axes of the input beams I ₁ , I ₂ ,..., I _2n can be arranged in parallel, that is, the LD chips LD ₁ , LD _{2 ,.} Each can be arranged in parallel. Therefore, since the light guide device 10 can increase the mounting density of the LD chips LD ₁ , LD ₂ ,..., LD _2n compared to the conventional light guide device, the light guide device 10 can be downsized compared to the conventional light guide device. can do.

As described above, in the light guide device 10, the number of the input beams I ₁ , I ₂ ,..., I _2n may be an even number of 2 or more. By arranging the unit optical system _{S k} described above into n parallel, light guiding device 10, the input beam _{I 1,} I 2 of 2n (n is a natural number), _..., an input beam bundle IB consisting of _{I 2n,} n output beam O _1, O _{2, ...,} after having converted to an output beam bundle OB consisting O _n, it is possible to direct the output beam bundle to the optical fiber. Therefore, the light guide device 10 can achieve a high output of the output beam bundle OB.

The upper limit of the output value of the output beam bundle OB of the light guide device 10 depends on the number of LD chips LD ₁ , LD ₂ ,..., LD _2n . The size of the light guide device gradually increases as the number of LD chips LD ₁ , LD ₂ ,..., LD _2n is increased. This tendency applies to both the light guide device 10 and the conventional light guide device. However, the degree to which the size increases as the number of LD chips increases is smaller in the light guide device 10 than in the conventional light guide device.

In a conventional light guide device, in a pair of LD chips (for example, GaAlAs-LD3 and 3 ′ described in FIG. 1 of Patent Document 1), the optical axis of the input beam emitted from each LD chip is They are orthogonal to each other. On the other hand, in the light guide device 10, the optical axis of the input beams I ₁ , I ₂ ,..., I _2n can be all along the x axis by including the composite optical system CO _k . Therefore, even when the number of the LD chips LD ₁ , LD ₂ ,..., LD _2n is increased, it is possible to prevent the size of the light guide device from becoming unnecessarily large.

  Thus, even when the output beam OB is increased in output by arranging a plurality of LD chips, it is possible to prevent the size of the light guide device from becoming unnecessarily large. Therefore, the higher the output of the output beam OB, the more pronounced the effect of the light guide device 10 (both high output beam bundle output and miniaturization of the light guide device).

  As described above, the light guide device 10 can achieve both high output beam bundle OB and miniaturization.

The input beams _{I 1, I 2, ...,} I 2k-1, I 2k, ..., since the wavelength of _{I 2n-1, I} 2n is a single, light guiding device 10, LD chip LD ₁ to be mounted , LD ₂ ,..., LD _2n can output an output beam bundle OB composed of one wavelength component regardless of the number. Therefore, the light guide device 10 can increase the output beam bundle OB composed of one wavelength component.

  On the other hand, in the light guide device of Patent Document 1, there is a trade-off relationship between increasing the output beam and suppressing the number of wavelength components included in the output beam. When suppressing the wavelength component contained in the output beam to one, the number of light sources that can be mounted on the light guide device is limited to two. This means that the output value of the output beam of the light guide device is lower than that of the light guide device 10.

(B) in FIG. 4 is a perspective view showing each of the beam profile of the input beam _{I 2k-1, I} 2k and the output beam _{O k.} In FIG. 4B, each of the first to third reflecting surfaces P _{k1 to} P _k3 and the combined surface P _kC is not shown, and the input beams I _2k−1 , I _2k and the output beam O _k. Only the optical axis and the beam profile are shown.

As described above, as indicated by A1, the input beam I _{2k-1 has} an elliptical beam profile that is long in the direction along the z-axis and short in the direction along the y-axis immediately after being emitted. Have. As indicated by A2, the input beam I _2k-1 reflected by the reflecting surface P _k1 has an elliptical beam profile that has a long direction along the y-axis and a short direction along the x-axis. As indicated by A3, the input beam I _2k-1 reflected by the reflecting surface P _k2 has an elliptical beam profile that has a long direction along the z-axis and a short direction along the x-axis. . The input beam I _2k-1 is incident on the synthesis plane P _kC with an elliptical beam profile having a long direction along the z-axis and a short direction along the x-axis.

Similarly, as indicated by B1, the input beam I _2k has an elliptical beam profile that is long in the direction along the z-axis and short in the direction along the y-axis immediately after being emitted. As indicated by B2, the input beam I _2k reflected by the reflecting surface P _k3 has an elliptical beam profile that is long in the direction along the y-axis and short in the direction along the x-axis. Further, the input beam I _2k reflected by the composite plane P _kC has an elliptical beam profile that is long in the direction along the z-axis and short in the direction along the x-axis.

As shown in B3, both of the input beam _{I 2k-1,} and is reflected on the combining surface _{P kC} input beam _{I 2k} incident on the synthesis plane _{P kC} is, the direction is long along the z-axis, and, x Since it has an elliptical beam profile with a short direction along the axis, the output beam _Ok is synthesized.

(LD module manufacturing method)
A method for manufacturing the LD module 1 will be described with reference to FIG.

This manufacturing method is realized by repeating the following steps T1 to T8 for the synthetic optical system CO _k (k = 1, 2,..., N).

The first mirror rotation step T1 is a step of slightly rotating the propagation direction of the output beam about the x axis as the rotation axis by slightly rotating the first mirror M _k1 about the z axis as the rotation axis.

The second mirror rotating step T2 is a step of slightly rotating the propagation direction of the output beam about the z axis as the rotation axis by slightly rotating the second mirror _Mk2 about the z axis as the rotation axis.

  The third mirror rotating step T3 is a step of slightly rotating the propagation direction of the output beam about the x axis as the rotation axis by slightly rotating the third mirror Mi3 about the z axis as the rotation axis.

The combiner rotation step T4 is a step of slightly rotating the propagation direction of the output beam about the z axis as the rotation axis by slightly rotating PBCC _k with the z axis as the rotation axis.

  By performing the first mirror rotation step T1 to the combiner rotation step T4, the first adjustment target of matching the propagation direction of each output beam constituting the output beam bundle with the y-axis direction is achieved.

The first mirror sliding step T5 is a step of translating the optical axis of the output beam in parallel with the x axis by translating the first mirror M _k1 in parallel with the x axis.

The second mirror sliding step T6 is a step of translating the optical axis of the output beam parallel to the z-axis by translating the second mirror _Mk2 parallel to the y-axis.

The third mirror sliding step T7 is a step of translating the optical axis of the output beam in parallel with the x axis by translating the third mirror _Mk3 in parallel with the x axis.

The combiner sliding step T8 is a step of translating the optical axis of the output beam in parallel with the z axis by translating PBCC _k in parallel with the y axis.

If the arranging at equal intervals in xz plane and a plane parallel to the optical axis of each output beam O _k constituting the output beams and the second adjustment target, the first mirror sliding step T5~ combiner sliding step The adjustment target value referred to in T8 may be determined as shown in FIG. That is, the beam spots of the output beam bundles may be determined so as to be arranged at equal intervals on the x axis in a plane parallel to the xz plane upstream from the F axis converging lens FL. In FIG. 6, w12 = w23 = w34 = w45 = w56 may be satisfied.

Further, as shown in FIG. 6, each of the output beam O _k in the longitudinal direction has an elliptical beam profile of along the z-axis.

As described above, the direction of the first reflecting surface P _k1 , the second reflecting surface P _k2 , the third reflecting surface P _k3 , and the combining surface P _kC is adjusted for the combining optical system CO _k , and (1) the input beam I _{2k -1,} and combining the output beam _{O k} from _{I 2k,} and to match the y-axis the optical axes of the (2) the output beam _{O k.}

  In addition, as shown in FIG. 5, the first mirror sliding step T5 to the combiner sliding step T8 constitute the output beam bundle by performing the first mirror rotating step T1 to the combiner rotating step T4. This is preferably performed after the propagation directions of the output beams are made parallel. However, the execution order of the first mirror rotation process T1 to the combiner rotation process T4 and the execution order of the first mirror sliding process T5 to the combiner sliding process T8 are not limited to those shown in FIG. That is, a configuration in which the first mirror rotation step T1 is performed after the second mirror rotation step T2 is performed may be adopted, or the first mirror sliding step T5 is performed after the second mirror sliding step T6 is performed. You may employ | adopt the structure which implements.

Further, the first mirror M _k1 is fixed to the substrate B, the second mirror M _k2 is fixed to the first mirror M _k1 , the third mirror M _k3 is fixed to the substrate B, and the third mirror M of PBCC _k . _{When an} adhesive is used for fixing to _k3 , this is preferably performed as follows. That is, the between the upper surface of the lower surface and the substrate B in the first mirror _{M k1,} between the upper surface of the lower surface of the second mirror _{M k2} first mirror _{M k1,} upper surface of the lower surface and the substrate B of the third mirror _{M k3} during, and after an adhesive is applied between the upper surface of the lower surface and the third mirror _{M k3} of PBCC _k, first mirror rotation step T1~ combiner rotation step T4, and the first mirror sliding step T5 -The combiner sliding step T8 is performed. However, the lower surface of the first mirror _Mk1 and the upper surface of the substrate B are parallel to each other during the execution of these steps and until the curing of the adhesive is completed after the completion of these steps. The lower surface of the second mirror M _{k2 and} the upper surface of the first mirror M _k1 are parallel, the lower surface of the third mirror M _k3 and the upper surface of the substrate B are parallel, and the lower surface of the PBCC _k and the third The state where the upper surface of the mirror _Mk3 is parallel is maintained. Accordingly, an adhesive layer formed between the lower surface of the first mirror M _k1 and the upper surface of the substrate B, and an adhesive formed between the lower surface of the second mirror M _{k2 and} the upper surface of the first mirror M _k1. layer, an adhesive layer formed between the upper surface of the lower surface and the substrate B of the third mirror M _k3, and, of the adhesive layer is formed between the lower surface and the upper surface of the third mirror M _k3 of PBCC _k The thickness can be made uniform.

[Second Embodiment]
An LD module according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a perspective view of the unit optical system Sk ′ included in the LD module 2 according to the present embodiment.

As illustrated in FIG. 7, the LD module 2 according to the present embodiment includes the light guide device 10 and the LD chip LD _{2k included in} the LD module 1 according to the first embodiment, respectively. It is obtained by changing to “and LD chip LD _2k” . In the LD module 2, members other than the light guide device 10 ′ and the LD chip LD _{2 k ′} are configured in the same manner as the LD module 1. Therefore, in the present embodiment, the light guide device 10 ′ and the LD chip LD _{2k ′} will be described. About the member comprised similarly to LD module 1, the code | symbol similar to LD module 1 is attached | subjected, and the description is abbreviate | omitted.

(LD chip)
Similar to the LD module 1, the LD module 2 includes 12 LD chips LD ₁ , LD _{2 ′} ,..., LD _2k−1 , LD _{2k ′} ,..., LD _2n−1 , LD _{2n−1 ′.} Yes. Among these, the LD chips LD1,..., LD _2k−1 ,..., LD _2n−1 arranged at odd numbers from the y-axis negative direction side are configured in the same manner as the LD module 1. On the other hand, LD chip LD ₂ disposed numbered counting from the y-axis negative direction side _{', ..., LD 2k',} ..., LD 2n ' is, LD chip _LD 2 of the LD module 1, ..., _{LD 2k,} ... , LD _2n , the oscillation wavelength is configured to be shorter. That, LD chip _{LD 2 ', ..., LD 2k} ', ..., LD 2n ' input beam I ₂ emitted from _{the', ..., I 2k ',} ..., I 2n' wavelength lambda _2k-1 of the input beam _{I 1, ..., I 2k-} 1, ..., shorter than the wavelength λ _2k of _{I 2n-1.} That is, each of the two input beams I _2k-1 and I _2k incident on the combining optical system CO _k has a different wavelength.

  In the present embodiment, the number 2n of LD chips included in the LD module 2 can be arbitrarily selected from two or more even numbers. That is, n is a natural number.

Wavelength lambda _2k-1 and the wavelength lambda _2k may be determined according to the transmission characteristic of the dichroic mirror DM _k to be described later (it can be said reflection property if Uragaese). For example, as a combiner, a rise wavelength is 917Nm, when the width of the rising region (region sandwiched by the transmission band and the reflection band) employs a dichroic mirror DM _k is 10 nm, the wavelength lambda _2k-1 and wavelength lambda _The wavelength λ _2k-1 and the wavelength λ _2k may be determined so that the difference from _2k is 10 nm or more. For example, the wavelength λ _2k-1 may be 922 nm and the wavelength λ _2k may be 912 nm.

When the LD module 2 is used for a fiber laser, a fiber amplifier, or the like, that is, when the output beam bundle OB from the LD module 2 is guided to the amplification optical fiber provided in the fiber laser, the fiber amplifier, or the like, the wavelength λ _2k− The difference between ₁ and the wavelength λ _2k is preferably set as small as possible in the wavelength region that is equal to or greater than the width of the rising region. This is because as the difference is smaller, the output beam bundle OB having a narrow spectrum distribution width can be guided to the amplification optical fiber, and the efficiency in exciting the amplification optical fiber can be increased. The reason is as follows.

For example, when an optical fiber doped with Yb ions is used as the amplification optical fiber, this optical fiber exhibits an absorption coefficient having a peak at 917 nm. Therefore, when pumping this optical fiber, considering the pumping efficiency, the wavelengths λ _2k−1 and λ _2k of the output beam bundle OB that is pumping light are most preferably equal to 917 nm, and when different from 917 nm, It is preferable that each has a wavelength as close to 917 nm as possible.

Therefore, when the output beam bundle OB is constituted by one wavelength component (λ _2k−1 = λ _2k ) as in the LD module 1, it is preferable that λ _2k−1 = λ _{2k ′} = 917 nm. On the other hand, when the output beam bundle OB is composed of two wavelength components (λ _2k−1 ≠ λ _{2k ′} ) as in the LD module 2, each of the wavelength λ _2k−1 and the wavelength λ _2k is (1) λc <λ _2k−1 , (2) λ _2k <λ _c , and (3) the difference between λ _{2k −1} and λ _2k (λ _2k−1 −λ _2k ) is equal to or greater than the width of the rising region It is preferable that the wavelength region is as small as possible. By using this configuration, it is possible to suppress a decrease in excitation efficiency even when the output beam bundle OB is composed of two wavelength components.

In recent years, a dichroic mirror having a rising region width of about 1 nm has also been realized. By adopting such a dichroic mirror as the dichroic mirror DM _k, it is possible to further suppress a decrease in pumping efficiency.

(Light guide device)
The light guide device 10 ′ is obtained by making the following changes to the light guide device 10 described in the first embodiment. The combined optical system CO _{k ′} included in the light guide device 10 _′ corresponds to the combined optical system CO _k included in the light guide device 10.

(Modification 1) As a combiner included in the light guide device 10 ′, a dichroic mirror DM _k is employed instead of the PBCC _k that is the combiner included in the light guide device 10.

Omitted (change 2) polarization rotation device _PR 1 light guiding device 10 is _equipped, ..., PR k, ..., a PR _n.

Instead of (change 3) synthesizing optical system CO _k first mirror comprising the _{M k1,} and a third mirror _{M k3,} the combining optical system CO _{k ',} to adopt the raising mirror _{M k13.}

  That is, in the light guide device 10 ′, members not related to the above-described changes 1 to 3 are configured in the same manner as the light guide device 10. Below, regarding the member comprised similarly to the light guide device 10, the member number similar to the light guide device 10 is attached | subjected, and the description is abbreviate | omitted.

The dichroic mirror DM _k which is the combiner described in the claims is an optical member made of glass (for example, quartz glass), and the interface of the glass member functioning as the synthetic surface P _kC described in the claims is (1 (1) A reflection / transmission film is formed which reflects light (input beam) having a wavelength shorter than a predetermined wavelength and (2) transmits light (input beam) having a wavelength longer than a predetermined wavelength. In the present embodiment, the composite surface P _kC described in the claims of the dichroic mirror DM _k is referred to as a composite surface P _kC ′.

For example, a dielectric multilayer film can be used as the reflection / transmission film constituting the composite surface P _kC ′.

Hereinafter, a wavelength region having a wavelength shorter than a predetermined wavelength and having a sufficiently low transmittance is referred to as a reflection band. A wavelength region having a wavelength longer than a predetermined wavelength and having a sufficiently high transmittance is referred to as a transmission band. A rising region including the rising wavelength, which is the predetermined wavelength, exists between the reflection band and the transmission band. In the rising region, the transmittance of the dichroic mirror DM _k is increased rapidly. Note that this predetermined wavelength preferably coincides with the above-described center wavelength λc.

The dichroic mirror DM _k, depending on the difference in wavelength and not the polarization direction of the light difference, or is reflected or not transmit the light. Some of the dichroic mirrors DM _k show the dependence of the transmittance and reflectance on the polarization direction of the incident light (polarization dependence). When the dichroic mirror DM _k employed in the light guide device 10 ′ does not have polarization dependency, the polarization rotation elements PR ₁ ,..., PR _k,. ..., PR _n may be omitted. On the other hand, when the dichroic mirror DM _k employed in the light guide device 10 ′ has polarization dependency, the polarization rotation elements PR ₁ ,..., PR _k , which the light guide device 10 includes also in the light guide device 10 ′. ..., PR _n is preferably provided.

In the synthesis optical system CO _{k ′} , the dichroic mirror DM _k transmits the input beam I _2k−1 reflected by the second mirror M _{k2 and also} reflects the input beam I _{2k ′} reflected by the rising mirror M _k13 . by reflecting in the direction along to the second axis, combining the output beam O _k.

As described above, the combining optical system CO _{k ′} includes the input beam bundle IB formed by the input beams I _2k−1 and I _{2k ′} whose optical axis is along the x axis, and the output beam O _k whose optical axis is along the y axis. Can be converted into an output beam bundle OB constituted by Therefore, the light guide device 10 ′ provided with the combined optical system CO _{k ′} can achieve both high output beam bundle OB and miniaturization, similar to the light guide device 10 according to the first embodiment. it can.

In the light guide device 10 ′, the wavelengths of the input beams I _2k−1 and I _{2k ′} are different. Therefore, the input beam bundle IB is composed of two wavelength components. Therefore, the output beam bundle OB converted from the input beam bundle IB consists of two wavelength components. Therefore, the light guide device 10 ′ can increase the output beam bundle OB composed of two wavelength components.

  On the other hand, in the light guide device of Patent Document 1, when the wavelength component included in the output beam is suppressed to two, the number of light sources that can be mounted on the light guide device is limited to four. This means that the output value of the output beam of the light guide device is lower than that of the light guide device 10 '.

Further, in the LD module 2, the synthesis optical system CO _{k ′} includes a rising mirror M _k13 instead of the first mirror M _k1 and the third mirror M _k3 . The raising mirror M _k13 is an optical member made of glass (for example, quartz glass), like the first mirror M _k1 and the third mirror M _k3 . The raising mirror M _k13 is formed by integrally forming the first mirror M _k1 and the third mirror M _k3 as one optical member. In the rising mirror M _k13 , the reflecting surface P _k13 reflects the input beam I _2k-1 whose optical axis is along the x-axis (first axis) in the direction along the z-axis (third axis), and the optical axis is The input beam I _2k along the x-axis (first axis) is reflected in the direction along the z-axis (third axis).

As described above, the rising mirror M _k13 corresponds to the first mirror M _k1 and the third mirror M _k3 of the combining optical system CO _k . The reflecting surface P _k13 corresponds to the first reflecting surface P _k1 and the third P _k3 of the composite optical system CO _k .

  According to said structure, the light guide apparatus 10 'which concerns on this embodiment has an effect similar to the light guide apparatus 10 which concerns on 1st Embodiment. Further, the LD module 2 including the light guide device 10 ′ has the same effect as the LD module 1 including the light guide device 10.

In the LD module 2, due to the provision of a mirror _{M k13} stand instead of the first mirror _{M k1,} and a third mirror _{M k3,} first mirror rotation step T1 and the third mirror rotating as shown in FIG. 5 The moving step T3 can be carried out at once, and the first mirror sliding step T5 and the third mirror sliding step t7 can be carried out collectively. Therefore, the adjustment process of the light guide device 10 ′ can be facilitated.

In the present embodiment employs a dichroic mirror DM _k constituted by dichroic cube prism is an example of a dichroic mirror. However, dichroic the dichroic mirror DM instead of _k, one dichroic mirror surface in the multilayer dielectric film is plate-shaped, which is formed of a glass plate may be employed.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

1, 2 LD module 10, 10 'light guiding device _{PR 1, ..., PR k,} ..., PR n polarization rotator _{CO 1, ..., CO k,} ..., CO k combining optical system _{M 11,} ..., M _k1 , _{..., M n1} first mirror _{M 12, ..., M k2,} ..., M n2 second mirror _{M 13, ..., M k3,} ..., M n3 third mirror _{C 1, ..., C k,} ..., C n Polarization-dependent beam combiner (combiner)
P _k1 , P _k2 , P _k3 , P _kC first reflecting surface, second reflecting surface, third reflecting surface, composite surface M _k13 rising mirror (first mirror and third mirror)
P _k13 reflective surface DM _k dichroic mirror (combiner)
P _kC 'combining surface 20 collimating optical system _{FC 1, FC 2, ...,} FC 2k-1, FC 2k, ..., FC 2n-1, FC 2n F -axis collimating lens _{SC 1, SC 2, ...,} SC 2k-1 , SC _2k ,..., SC _2n−1 , SC _2n S-axis collimating lens 30 Converging optical system FL F-axis converging lens SL S-axis converging lens B Substrate BS Surface (specific plane)
_{LD1, LD2, ..., LD 2k} -1, LD 2k, ..., LD 2n-1, LD 2n, LD 2 ', ..., LD 2k', ..., LD 2n 'LD chip _{I 1, I 2, ...,} I _{2k-1, I 2k, ...} , I 2n-1, I 2n input beam IB input beam bundle _{O 1, O 2, ...,} O 2k-1, O 2k, ..., O 2n-1, O 2n output beam OB Output beam bundle OF optical fiber

Claims (10)

An input beam bundle made up of 2n (n is a natural number) input beams I ₁ , I ₂ ,..., I _2n whose optical axis is along the first axis, and n output beams O ₁ whose optical axis is along the second axis. , _O 2, ..., in the light guide device into an output beam bundle consisting of _{O n,}
Two input beams _{I 2k-1, I 2k (} k = 1,2, ..., n) an output beam _{O k} to synthesize combining optical system CO _k from the (1) input beam _{I 2k-1} second A first mirror M _k1 that reflects in the direction along the three axes; and (2) a second mirror M _k2 that reflects the input beam I _2k−1 reflected by the first mirror M _{k1 in the} direction along the second axis. (3) the third mirror M _k3 that reflects the input beam I _2k in the direction along the third axis; and (4) the input beam I _2k-1 reflected by the second mirror M _k2 is transmitted and A combining optical system CO _k including a combiner C _k that combines the output beam O _k by reflecting the input beam I _2k reflected by the three mirrors M _{k3 in a} direction along the second axis;
A light guide device. N is a natural number of 2 or more;
Each of the two input beams I _2k-1 and I _2k incident on the combined optical system CO _k has the same wavelength and the same plane of polarization,
The combining optical system CO _k further includes a polarization rotation element arranged at the front stage of the first mirror M _k1 or the front stage of the third mirror M _k3 ,
The combiner C _k is a polarization dependent beam combiner.
The light guide device according to claim 1. Each of the two input beams I _2k-1 and I _2k incident on the combined optical system CO _k has a different wavelength,
The combiner C _k is a dichroic mirror.
The light guide device according to claim 1. Each of the first mirror M _k1 and the third mirror M _k3 is placed on a specific plane stretched by the first axis and the second axis,
The second mirror M _k2 is placed on the first mirror M _k1 ,
The combiner C _k is placed on the third mirror M _k3 ,
The optical axes of the two input beams I _2k-1 and I _2k are aligned in a plane parallel to the specific plane,
For the synthetic optical system CO _k, the first reflecting surface _{P k1} first is a reflective surface constituting the mirror _{M k1,} the second second reflecting surface _{P k2} is a reflecting surface constituting a mirror _{M k2,} the first 3 mirror M _k3 third reflecting surface P _k3 a reflecting surface that constitutes _the, and, each of the synthetic surface P _kC constituting the combiner C _k is the optical axis of the output beam O _k is coincident with the second axis Have been adjusted to,
The light guide device according to claim 1, wherein the light guide device is a light guide device. Each of the first reflecting surface P _k1 and the third reflecting surface P _k3 has a normal vector located in a plane extending by the first axis and the third axis, and the normal vector And the third axis is 45 °,
Each of the second reflective surface P _k2 and the composite surface P _kC has a normal vector located in a plane extending by the third axis and the second axis, and the normal vector and the The angle formed with the third axis is 45 °,
The light guide device according to claim 4. The first mirror M _k1 and the third mirror M _k3 are integrally formed.
The light guide device according to any one of claims 4 and 5. The optical axes of the input beams I ₁ , I ₂ ,..., I _2n are arranged at equal intervals, respectively.
For the synthetic optical system CO _k, the first reflecting surface _{P k1,} the second reflecting surface _{P k2,} the third reflecting surface _{P k3,} and combining surface _{P kC,} the output beam _{O 1,} O 2, ..., the _{O n} Each optical axis is adjusted so as to be arranged at equal intervals in a plane parallel to the specific plane.
The light guide device according to claim 4, wherein the light guide device is a light guide device. The light guide device according to any one of claims 1 to 7,
The input beam _{I 1, I 2, ...,} LD chip _{LD 1,} LD 2 for emitting respective each of _{I 2n,} ..., and _{LD 2n,}
The converted by the light guiding device output beam O _1, O _{2, ...,} and an optical fiber coupled to O _n,
A collimating optical system inserted between the LD chips LD ₁ , LD ₂ ,..., LD _2n and the combining optical system CO _k, and F-axis collimating lenses FC ₁ , FC _{2 ,.} the F-axis collimating lens _{FC 1, FC 2, ...,} S -axis collimating lens _SC 1 which is disposed downstream of the _{FC 2n,} SC _{2, ...,} a collimating optical system configured by the _{SC 2n,,}
A condensing lens system that is inserted between the light guide device and the optical fiber, and is configured by an F-axis converging lens and an S-axis converging lens disposed at a subsequent stage of the F-axis converging lens A converging optical system,
LD module characterized by the above. The substrate further includes a substrate on which the first mirror M _k1 and the third mirror M _k3 constituting the light guide device are mounted,
Each of the LD chips LD ₁ , LD ₂ ,..., LD _2n is disposed such that each active layer is along the surface of the substrate.
The LD module according to claim 8. A manufacturing method for manufacturing the light guide device according to claim 1,
For each of the combining optical systems CO _{k, the directions} of the first mirror M _k1 , the second mirror M _k2 , the third mirror M _k3 , and the combiner C _k are: (1) the input beam I _2k−1 , to synthesize the output beam O _k from I _2k, and, (2) so that the optical axis of the output beam O _k coincides with the second axis includes the step of adjusting,
The manufacturing method characterized by the above-mentioned.

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