JP2022089652A - Optical module - Google Patents

Abstract

To provide an optical module that can monitor returned light while suppressing output light attenuation in the optical module using light sources, especially semiconductor lasers.SOLUTION: In an optical module 1 in which light irradiated from a light source is guided to a predetermined location by a reflector 50, a reflective surface 51 and a light-transmitting portion 52 are formed on the reflector, and light irradiated from the light source is irradiated on the reflective surface. On the back of the reflector, a light-receiving part 80 is provided to detect returned light RL transmitted through the light-transmitting portion. When the light source is a semiconductor laser, the light-transmitting portion is provided in parallel with a long axis of a cross section of the light ray.SELECTED DRAWING: Figure 1

Description

The present invention relates to an optical module, particularly an optical module having a configuration in which a high-power laser is obtained by synthesizing laser light emitted by a plurality of semiconductor lasers.

Lasers are used in various fields such as material processing fields typified by metals and medical fields by utilizing their high energy density. Especially in the material processing field, the output of the laser is increased for the purpose of shortening the processing time.

As a kind of laser used in the material processing field, there is a laser having a configuration called DDL (Direct Diode Laser). Hereinafter, DDL will be briefly described.

As described in Patent Document 1, the DDL uses a module in which a plurality of semiconductor lasers are combined, and one laser beam emitted from each semiconductor laser is used as one by using an optical member such as a lens and a reflection mirror. This is a method of synthesizing with laser light and irradiating the object to be processed.

In the scene where DDL is used, the synthesized laser light may be directly applied to the object to be processed, but there is a phenomenon that the laser light reflected by the object to be processed returns to the inside of the module.

The synthesized laser light may be coupled to the optical fiber and guided to the object to be processed through the optical fiber. Even in this case, the laser light reflected by the object to be processed is coupled to the optical fiber again to form an optical system. By running in the opposite direction, the phenomenon of returning to the inside of the module occurs.

Since this return light causes problems such as destruction of the semiconductor laser and temperature rise of the module, there are cases where control such as monitoring the return light and stopping the laser output when the return light increases is performed. ..

In addition, by monitoring the return light, the operating status of the module, the machining status of the object to be machined, and the like are determined, and feedback control is performed so that more desirable motion and machining are performed.

As a method of monitoring the return light in various laser devices, a method of providing a photodetector such as a photodiode along the optical fiber to monitor the light leaking from the side surface of the optical fiber (for example, Patent Document 2), or a method of monitoring light in a module. Examples thereof include a method of monitoring return light by providing a detection element (for example, Patent Document 3).

However, in the method of monitoring the light leaking from the side surface of the optical fiber, as pointed out in Patent Document 2, not only the light leakage derived from the return light but also the light leakage derived from the output light toward the object to be processed is detected. Difficulties are associated with detecting the amount of return light.

On the other hand, in the case of the method of monitoring the return light in the module, as described in Patent Document 3, a part of the return light is branched by an optical branching member such as an optical splitter or a half mirror, and the light is guided to the photodetection element. However, this method has a problem that the output laser light is attenuated when it passes through the photobranching member.

JP-A-2007-142439 WO2013 / 108769A Japanese Unexamined Patent Publication No. 11-121834

An object of the present invention is to provide an optical module using a semiconductor laser typified by DDL, which can monitor return light while suppressing attenuation of output light.

As a result of diligent examination of the configuration of the optical module, the inventor forms a reflecting surface and a light transmitting portion on the reflecting body used for the optical module, irradiates the reflecting surface with the irradiation light from the light source, and emits the return light. It was found that the above problem can be solved by taking it out from the transparent part.

The optical module of the present invention is an optical module that guides light emitted from a plurality of light sources to a predetermined place, and a reflector that reflects the light in a predetermined direction is provided in the optical module to reflect the light. The body is characterized in that a reflecting surface and a light transmitting portion are formed, and the irradiation light from the light source irradiates the reflecting surface.

The optical module of the present invention contributes to suppressing the attenuation of the output light because the output light is guided to the object only by reflection without transmitting the member for guiding the return light to the light receiving unit. It shows an excellent effect.

This is the basic configuration of the present invention. It is a figure which shows the state of a light ray, and the positional relationship of a light transmitting part when a light source is a semiconductor laser. It is an example of an optical module which is an embodiment of the present invention. This is an example of a reflector used in the present invention. This is a modification of the reflector used in the present invention. It is another modification of the reflector used in this invention.

Hereinafter, aspects of the optical module to which the present invention is applied will be described with reference to FIG.
The optical module (1) to which the present invention is applied has N light sources (N is a natural number of 2 or more), N = 4 in FIG. 1, and a semiconductor laser that irradiates a laser beam is used as the light source. The case will be described.

Within the scope of the technical idea of the present invention, N can be arbitrarily set, and a light source other than the semiconductor laser may be used.

The optical module (1) shown in FIG. 1 is a FAC lens (20-1 to 20-1) that collimates the first to fourth light rays (L1 to L4) emitted from the first to fourth light sources (10-1 to 4). 4), the SAC lens (30-1 to 4), the reflector (50) that reflects each collimated light ray toward the condenser lens (60), and each ray focused by the condenser lens (60). It has an optical fiber (70) to which the lens is coupled, but what is essential for the present invention is a light source (10-1 to 4) and a reflector (50).

What is characteristic of the present invention is that a reflecting surface (51) and a light transmitting portion (52) are formed on the reflector (50), and the light is irradiated from the first to fourth light sources (10-1 to 4). All the first to fourth rays (L1 to L4) are applied to the reflecting surface (51).

The light rays (L) emitted from each light source (10) are applied to the reflective surface (51) of the reflector (50).
Since the light is guided to the condenser lens (60) side by the reflection, the attenuation of the light ray (L) in the reflector (50) is minimized, which contributes to the suppression of the attenuation of the output light.

In the present invention, as a general rule, all the light rays (L) are applied to the reflective surface (51) of the reflector (50), so that the light rays (L) are less attenuated in the reflector (50).

Further, the return light (RL) usually returns to the reflector (50) from the condenser lens (60) side, but the return light (RL) has a specific shape and intensity by using a FAC lens (20) or the like. Generally, it returns to the reflector (50) in a state having a shape and an intensity distribution different from those of the first to fourth rays (L1 to L4) molded into the distribution.

Therefore, due to the presence of the light transmitting portion (52) in the reflecting body (50), a part of the return light (RL) passes through the light transmitting portion (52) and is guided to the back surface side of the reflecting body (50). The light is emitted, and by providing the light receiving unit (80) on the back surface of the reflector (50), the return light (RL) can be detected and monitored.

In the present invention, the first to fourth rays (L1, to L4) irradiated to the reflector (50) and reflected in a predetermined direction are coupled to the optical fiber (70) via the condenser lens (60). In this case, the return light (RL) that has traveled backward through the optical fiber (70) irradiates the reflector (50), and the return light (RL) irradiates the reflector (50). Is configured to include a light transmitting portion (52).

The return light (RL) from the optical fiber (70) is emitted from the optical fiber (70) at a spread angle according to the number of openings of the optical fiber (70), and the return light (RL) is emitted from the reflector (50). It is preferable that the portion having the highest intensity distribution of the return light (RL) is irradiated to the light transmitting portion (52) when the light transmitting portion (RL) reaches. With this configuration, the portion of the return light (RL) having a particularly high intensity passes through the light transmitting portion (52), so that the amount of light when the return light (RL) is detected on the back surface of the reflector (50). Can be enhanced.

Normally, the return light (RL) from the optical fiber (70) is emitted as a Gaussian beam, and the intensity distribution is highest near the central axis of the return light (RL).

That is, in the present invention, in the space (optical path) between the reflector (50) and the optical fiber (70), the central axes of the first to fourth rays (L1 to L4) and the return light (RL). It can be said that the intention is not to match the central axes.

It should be noted that it is not always necessary to configure the portion having a high intensity of the return light (RL) to pass through the light transmitting portion (52), and the reflector (50) is within the range where the required intensity of the return light (RL) can be obtained. ), The position of the light transmitting portion (52) can be arbitrarily set.

The position and shape of the light transmitting portion (52) are determined based on the state of the first to fourth light rays (L1 to L4), the state of the return light (RL), and the like, and are determined by the light source (10-1 to 4). When a semiconductor laser that irradiates a laser beam is used, the positions and shapes of the light transmitting portion (52) are preferably those described below.

When the light source (10-1 to 4) is a semiconductor laser, the cross-sectional shape of the first to fourth rays (L1 to L4) is usually a substantially elliptical shape having a long axis and a short axis as shown in FIG. The reflector (50) is configured so that the long axes of the cross sections of the first to fourth rays (L1 to L4) are parallel to each other.

At this time, a substantially rectangular non-irradiated region is formed between the first to fourth rays (L1 to L4) whose major axes are parallel to each other. On the surface of the reflector (50) on which the reflecting surface (51) and the light transmitting portion (52) are formed, a method of forming the light transmitting portion (52) in the region corresponding to the non-irradiated region can be preferably used.

In other words, when the light source (10) is a semiconductor laser, the light transmitting portion (52) is a substantially elliptical light beam emitted by the semiconductor laser having a major axis and a minor axis in cross section, as shown in FIG. It is preferable to provide the reflector (50) so that the shape is parallel to the long axis with respect to L).

By providing the light transmitting portion (52) in this way, it is possible to reliably reflect the light beam (L) and suppress the area of the light transmitting portion (52) required for transmitting the return light (RL). The size of the reflector (50) can be minimized.

Normally, as shown in FIG. 2, the shape of the light transmitting portion (52) is a rectangle whose width direction is longer than the height direction, and the width direction is with respect to the long axis of the light ray (L). It should be parallel.

In FIG. 2, only one light transmitting portion (52) is provided, but if there is a non-irradiated region between each light beam, a plurality of light transmitting portions (52) may be provided as needed. Further, when the non-irradiated region between the light rays is narrow and it is difficult to form a sufficient light transmitting portion (52), a method of forming the light transmitting portion (52) outside the light beam group, a light source (10), or a light source. A method of adjusting the arrangement of the optical components attached to (10) to provide a non-irradiated region having a sufficient width for forming the light transmitting portion (52) can be used.

In the most ideal configuration of the reflector (50), the reflecting surface (51) is provided only in the region irradiated with the light rays (L) from each light source (10), and the light transmitting portion (52) is provided in the other regions. ).

As described above, the present invention is carried out in the form of providing a light receiving portion (80) for receiving the return light (RL) transmitted through the light transmitting portion (52) on the back surface of the reflector (50). The photodetector (80) usually uses a photodetector such as a photodiode that detects the return light (RL) and converts it into an electrical signal, but it absorbs the return light (RL) and safely uses its energy. A damper for processing may be used.

In the reflector (50) of the present invention, a dielectric multilayer reflective film or a metal vapor deposition film is provided on a substrate made of synthetic quartz, BK7 glass, or the like to form a region to be a reflective surface (51), and a light transmitting portion is formed. A dielectric multilayer antireflection film or a metal vapor deposition film is not provided in the region (52), or a dielectric multilayer antireflection film is provided on the substrate.

[Example 1]
As a first embodiment of the present invention, the optical module (100) shown in FIG. 3 is shown. The optical module (100) has a submodule (200) having a plurality of light sources (10) in a housing (not shown), and is emitted from a light source (10) included in the submodule (200). A light ray (L) is coupled to an optical fiber (70) through an optical system composed of a lens or a mirror, and the light ray transmitted through the optical fiber (70) is irradiated to an object.

The sub-module (200) is composed of a sub-module bottom plate (210) and a light source, a lens, and mirrors provided on the sub-module bottom plate (210).

The sub-module bottom plate (210) is provided with a first staircase portion (221) and a second staircase portion (222) parallel to the first staircase portion (221).

The first staircase portion (221) is provided with first to twelfth light source installation surfaces in order from the upper stage, and first to twelfth light sources (10-1 to 12) are provided on the respective light source installation surfaces.

The height difference between adjacent light source installation surfaces and the area of each light source installation surface are formed to be equal.

The first to twelfth light sources (10-1 to 12) are semiconductor lasers (LDs) having a wavelength of 915 nm and an output of 8.3 W, and have an embodiment in which a semiconductor laser element is arranged on a submount.

FAC lenses (20-1 to 12) that collimate the speed axis direction of the first to twelfth rays (L1 to L12) are provided near the emission surface of the first to twelfth light sources (10-1 to 12). ..

Each light source is connected by a lead frame (not shown) so that the first to twelfth light sources (10-1 to 12) are connected in series. A current is supplied to the first to twelfth light sources (10-1 to 12) through electrodes (not shown) provided near the first step portion (221).

The first to twelfth mirror installation surfaces are provided on the second staircase portion (222) in order from the upper stage, and the first to twelfth mirrors (40-1 to 12) are provided on the respective mirror installation surfaces.

The height difference between adjacent mirror installation surfaces and the area of each mirror installation surface are formed to be equal. Further, the height of the first to twelfth mirror installation surfaces is set to a height lower than the height of the first to twelfth light source installation surfaces by a predetermined amount, respectively.

The mirror (40) has a dielectric multilayer reflective film provided on the base material, and has a high reflectance with respect to the wavelength output by the light source (10). The height of the mirror (40) is the light beam emitted from the light source installed on the upper stage of the corresponding light source installation surface while reflecting the light ray emitted from the light source installed on the corresponding light source installation surface in a predetermined direction. It is set to a height that does not interfere with.

A SAC lens (30-1 to 12) that collimates the slow axis direction of the first to twelfth rays (L1 to L12) is provided between the first staircase portion (221) and the second staircase portion (222). Be done. The first to twelfth rays (L1 to L12) transmitted through the SAC lens (30) have a substantially elliptical shape having a major axis and a minor axis, similar to the cross-sectional shape of the ray (L) shown in FIG. The 12 mirrors (40-1 to 12) are irradiated.

The first to twelfth rays (L1 to L12) reflected by the first to twelfth mirrors (40-1 to 12) are sub as a ray group (LG) in a state where the central axes are aligned when viewed in a plan view. Emitted from the module (200). When the ray group (LG) is viewed in cross section in the direction perpendicular to the central axis, as shown in FIG. 4A, the collimated first to twelfth rays (L1 to L12) are arranged in parallel along the vertical direction. It has become.

The light ray group (LG) is irradiated to the reflector (50) provided in the housing, and the reflector (50) reflects the light ray group (LG) toward the condenser lens (60). The light group (LG) is focused and coupled to the optical fiber (70) by the condenser lens (60). The optical fiber (70) transmits a laser beam of up to about 100 W. The light ray group (LG) irradiated to the reflector (50) is adjusted in light ray size with a target size of 4 mm in width × 4.2 mm in height.

The reflector (50) is made of a quartz glass substrate having a width of 8 mm, a height of 8 mm, and a thickness of 1 mm as a base material, and a reflective surface formed by a dielectric multilayer reflective film in a range of a width of 8 mm and a height of 4.4 mm at the center in the height direction. (51) is provided, and a dielectric multilayer antireflection film is provided in the range of width 8 mm × height 1.8 mm remaining at the upper end and the lower end, respectively, and the light transmitting portion (52) is used. A schematic diagram of the reflector (50) in Example 1 is shown in FIG.

The light transmitting portion (52) in the first embodiment is provided on the outside of the region irradiated with the light beam group (LG) substantially parallel to the long axis of the cross section of each light ray.

On the back surface of the reflector (50), a photodiode that receives the return light (RL) from the optical fiber (70) is provided as a light receiving unit (80).

[Evaluation of output loss due to reflector]
In the optical module (100) of the embodiment configured as described above, the intensity of the light beam group (LG) irradiated to the reflector (50) and the light reflected by the reflector (50) to the condenser lens (60). The intensity of the light beam group (LG-R) heading toward the light beam group (LG-R) is compared, and the output loss due to the reflector (50) is evaluated.

Evaluation is performed at room temperature (20 ° C.).

By supplying power to the sub-module (200) and outputting a laser beam of 8.3 W from each light source (10), a laser beam of about 100 W is output from the sub-module (200).

An optical power meter having sufficient performance to receive the light ray group (LG) is temporarily installed in front of the reflector (50) (point A in FIG. 3), and the intensity of the light ray group (LG) is measured.

Between the reflector (50) and the condenser lens (60) (point B in FIG. 3), the same optical power meter used for measuring the intensity of the ray group (LG) is temporarily installed, and the reflected ray group (LG-) is temporarily installed. The intensity of R) is measured and compared with the intensity of the ray group (LG).

In Example 1, when a laser beam of about 100 W was output from the submodule (200), the intensity of the light ray group (LG) was 97.5 W, and the intensity of the reflected light ray group (LG-R) was 96.7 W. rice field. The permissible value of output loss in a mirror or the like that reflects light used in a laser device such as the first embodiment is generally said to be about 1 to 2%, but the reflector (50) of the first embodiment. The output loss due to the above is about 0.8%, which is an output loss within an acceptable range for using the optical module (100).

The intensity of the light beam group (LG) is reduced from 100 W due to the attenuation when passing through the FAC lens (20), the SAC lens (30), and the like.

[Evaluation of return light]
In the optical module (100) of the embodiment, the intensity of the return light (RL) received by the light receiving unit (80) is evaluated.

Evaluation is performed at room temperature (20 ° C.).

An optical fiber made of quartz glass having a core diameter of 200 μm, a cladding diameter of 220 μm, and NA = 0.22 is used as the optical fiber (70), and both the incident end and the emitted end are optically polished in a flat shape to form a light transmitting portion (52). Provide the same dielectric multilayer antireflection film as used. The length of the optical fiber (70) is 50 mm.

A lens unit having a collimating lens for parallelizing the light emitted from the optical fiber (70) and a condensing lens for condensing the parallelized light on an object is placed in front of the emission end of the optical fiber (70). Arranged, the light emitted from the optical fiber (70) is irradiated and focused on the object via the lens unit.

The lens unit is arranged so that its focal point coincides with the exit end of the optical fiber (70) and the position where the object is present. Further, the mirror (40) used for the sub-module (200) is used as the object, and the object exhibits a reflectance of approximately 100% with respect to the emitted light.

By supplying power to the sub-module (200) and outputting 8.3 W of laser light from each light source (10), about 100 W of laser light is output from the optical module (100) and through the optical fiber (70). Irradiate the object with laser light.

A part of the laser beam reflected on the surface of the object returns to the optical module (100) as return light (RL) by re-incidention to the optical fiber (70), and is collimated by the condenser lens (60). After that, the reflector (50) is irradiated.

FIG. 4B shows a schematic diagram of the irradiation state of the return light (RL) on the reflector (50) in the first embodiment. The return light (RL) is emitted from the optical fiber (70) and then collimated by the condenser lens (60) to irradiate the reflector (50) in a substantially circular state.

Of the return light (RL), the light (RL-r) irradiated to the reflecting surface (51) becomes the return light to the submodule (200) side and is provided at the upper end and the lower end of the reflector (50). The light (RL-t) irradiated to the light transmitting portion (52) becomes the return light (RL) toward the light receiving portion (80).

When 100 W of laser light was output from the optical module (100) in Example 1, the intensity of the return light (RL) received by the light receiving unit (80) was 1.6 W. The strength is sufficient and necessary for monitoring the operating state of the optical module (100).

From the results of Example 1, it was confirmed that the necessary and sufficient return light (RL) can be detected while suppressing the output loss of the light irradiating the object according to the present invention.

[Example 2]
As the reflector (50), a reflective surface (51) made of a dielectric multilayer reflective film is provided on the front surface of the central portion in the height direction of a quartz substrate having a width of 8 mm, a height of 8 mm, and a thickness of 1 mm, of which the width of the central portion is 8 mm. × The range of 0.05 mm in height was configured in the same manner as in Example 1 except that the reflective surface (51) was removed and a dielectric multilayer antireflection film was provided to form a light transmitting portion (52). The optical module (100) is used as a second embodiment of the present invention. A schematic diagram of the reflector (50) in Example 2 is shown in FIG.

When the ray group (LG) in Example 2 is viewed in cross section in a direction perpendicular to the central axis, as shown in FIG. 5A, collimated first to twelfth rays (L1 to L12) are viewed in a cross-sectional manner as in Example 1. ) Are in parallel along the vertical direction.

The light transmitting portion (52) in the second embodiment is provided substantially parallel to the long axis of the cross section of each light ray in the gap of the region irradiated with the sixth light ray (L6) and the seventh light ray (L7). It is in a state.

In the return light (RL) in the second embodiment, as shown in FIG. 5 (b), the light (RL-t) irradiated near the center of the reflector (50) is returned toward the light receiving unit (80). It becomes light (RL), and the light (RL-r) irradiated to other regions becomes the return light to the submodule (200) side.

For the optical module (100) of Example 2, the output loss due to the reflector (50) and the return light were evaluated in the same manner as in Example 1.

The intensity of the light ray group (LG) in Example 2 was 97.5 W, and the intensity of the reflected light ray group (LG-R) was 96.5 W. The output loss due to the reflector (50) is about 1%, which is an acceptable range for using the optical module (100).

The intensity of the return light (RL) received by the light receiving unit (80) in Example 2 was 1.5 W. The strength is sufficient and necessary for monitoring the operating state of the optical module (100).

In Examples 1 and 2, the output loss due to the reflector (50) and the intensity of the return light (RL) are the same, but the area occupied by the light transmitting portion (52) on the reflector (50) is that of Example 2. Is smaller. From this, it can be evaluated that the embodiment of the second embodiment can efficiently detect the return light (RL) by the configuration in which the central portion having a high intensity of the return light (RL) passes through the light transmitting portion (52).

[Example 3]
As the reflector (50), a quartz glass substrate having a width of 8 mm, a height of 8 mm, and a thickness of 1 mm is used as a base material, and reflection is performed by a dielectric multilayer reflective film in a range of a width of 8 mm and a height of 4.6 mm at the center in the height direction. In addition to the light transmitting portion (52) provided with the surface (51) and the dielectric multilayer antireflection film provided in the range of width 8 mm × height 1.7 mm remaining at the upper end and the lower end, respectively, the central portion of the reflective surface (51). Example 1 except that the reflective surface (51) in the range of 2 mm in width × 0.1 mm in height was removed and a light transmitting portion (52) provided with a dielectric multilayer antireflection film was also formed. A third embodiment of the present invention is an optical module (100) configured in the same manner as above. A schematic diagram of the reflector (50) in Example 3 is shown in FIG.

When the light beam group (LG) in Example 3 is cross-sectionally viewed in a direction perpendicular to the central axis, as in Examples 1 and 2, as shown in FIG. 6A, collimated first to twelfth light rays (L1). ~ L12) are in parallel along the vertical direction.

The light transmitting portion (52) in the third embodiment is provided in the outside of the region irradiated with the light ray group (LG) and in the gaps between the regions irradiated with the sixth light ray (L6) and the seventh light ray (L7). A light transmitting portion (a light transmitting portion) formed in a gap between a region irradiated with a sixth light ray (L6) and a seventh light ray (L7), which is provided substantially parallel to the long axis of the cross section of each light ray. Regarding 52), it is provided only near the center of the reflector (50).

As shown in FIG. 6B, the return light (RL) in the third embodiment is the light receiving portion of the light (RL-t) irradiated to the upper end portion / the lower end portion and the vicinity of the center of the reflector (50). It becomes the return light (RL) toward (80), and the light (RL-r) irradiated to other regions becomes the return light toward the submodule (200) side.

For the optical module (100) of Example 3, the output loss due to the reflector (50) and the return light (RL) were evaluated in the same manner as in Examples 1 and 2.

The intensity of the light ray group (LG) in Example 3 was 97.5 W, and the intensity of the reflected light ray group (LG-R) was 95.6 W. The output loss due to the reflector (50) was about 1.9%, which was higher than that of Examples 1 and 2, but remained within an acceptable range for using the optical module (100).

The intensity of the return light (RL) received by the light receiving unit (80) in Example 3 was 2.6 W, which was increased by 50% or more as compared with Examples 1 and 2.

From the above results, the embodiment of Example 3 can be evaluated as an embodiment that can be used when it is necessary to detect more return light (RL).

As described above, by adopting the present invention, it was confirmed that the light receiving unit (80) can detect the necessary and sufficient return light (RL) while suppressing the output loss due to the reflector (50).

It goes without saying that the above-described embodiment is merely an example of the present invention, and various modifications and applications are possible within the scope of the idea of the present invention, and are appropriately modified and provided. For example, in order to adjust the size of the light beam group (LG) in the embodiment, the components of the optical module (100) are appropriately changed and adjusted, such as arranging the SAC lens (30) in the optical path at an angle. Is possible.

The optical module of the present invention is a laser module using a plurality of semiconductor lasers used as a light source of a laser device for material processing, as well as projecting light on an object and receiving and determining reflected light from the object. It can also be used as a light source device for evaluating the state of an object.

1 Optical module 10 Light source 20 FAC lens 30 SAC lens 40 Mirror 50 Reflector 51 Reflective surface 52 Light transmitting part 60 Condensing lens 70 Optical fiber 80 Light receiving part 100 Optical module 200 Submodule 210 Submodule bottom plate 221 First staircase part 222 2nd staircase 300 Housing 301 Lid 302 Bottom plate 303 Bulk upper L ray RL Return light LG, LG-R ray group

Claims (7)

An optical module having N light sources (N is a natural number of 2 or more), and the i-ray ray emitted from the i-th light source (i is a natural number of N or less) is reflected in a predetermined direction in the optical module. A reflecting body is provided, and a reflecting surface and a light transmitting portion are formed on the reflecting body, and all the first to Nth rays radiated from the first light source to the Nth light source are formed on the reflecting surface. An optical module characterized by being irradiated. Each of the first to Nth rays irradiated on the reflector is reflected by the reflector in a predetermined direction, and then is coupled to the optical fiber via a condenser lens, and the optical fiber is formed. The optical module according to claim 1, wherein a retrograde return light is applied to the reflector, and the light transmitting portion is included in a range in which the return light irradiates the reflector. .. The second aspect of the present invention is characterized in that, in the space between the reflector and the optical fiber, the central axes of the first to Nth rays and the central axes of the return light do not coincide with each other. Described optical module. The N light sources are semiconductor lasers in which the cross-sectional shapes of the light rays to be irradiated are substantially elliptical on the long axis and the short axis, and the long axes of the cross-sectional shapes of each of the first light rays to the Nth light rays are parallel to each other. The optical module according to any one of claims 1 to 3, wherein the reflector is irradiated in a state and the light transmitting portion is provided substantially parallel to the long axis. .. The optical module according to claim 4, wherein the light transmitting portion is formed between a region where the i-th ray and the i + 1-th ray are irradiated on the reflector. The optical module according to any one of claims 1 to 5, wherein a plurality of the light transmitting portions are provided on the reflector. The optical module according to any one of claims 2 to 6, wherein a light receiving unit for receiving the return light transmitted through the light transmitting unit is provided.

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