JP5415828B2 - Laser apparatus and semiconductor laser module - Google Patents

Description

  The present invention relates to a laser device and a semiconductor laser module mainly used in the field of optical communication.

  In general, a semiconductor laser module is used as a signal light source in optical communication, an excitation light source of an optical fiber amplifier, or the like.

  2A and 2B are explanatory views showing an example of a conventional semiconductor laser module.

  As shown in FIG. 2A, a conventional semiconductor laser module M1 includes a light emitting element 50 such as a laser diode (semiconductor laser element), a parallel lens 51 that collimates laser light emitted from the light emitting element 50, A first beam splitter 52 that divides the laser beam paralleled by the parallel lens 51 into two, and a first light receiving element such as a photodiode that receives one of the laser beams branched by the first beam splitter 52 53, a second beam splitter 54 for splitting the other laser beam split by the first beam splitter 52 into two, and one laser beam split by the second beam splitter 54 for light such as an etalon. A second light receiving element 56 such as a photodiode that receives light after passing through the filter 55 and a second beam splitter 54. A condensing lens 57 for condensing the other branched laser light, and an optical fiber 58 for receiving the laser light condensed by the condensing lens 57 and transmitting it to the outside (hereinafter, this technique is a conventional example). 1).

  In addition, as shown in FIG. 2B, one laser beam branched by the beam splitter 59 is received by the first light receiving element 53 and received by the second light receiving element 56 through the optical filter 55. A semiconductor laser module M2 is known (hereinafter, this technique is referred to as Conventional Example 2).

Further, Patent Document 1 proposes a pentagonal optical component in which laser light emitted from a light emitting element is incident on at least two surfaces and branched into three branched lights by reflection and transmission (hereinafter, this is referred to as “this”). The technology is referred to as Conventional Example 3).
JP 2004-246291 A

  Since the conventional example 1 requires two beam splitters, the number of components and the space for installing components increase, leading to an increase in the size of the device, an increase in power consumption necessary for temperature adjustment, and an increase in manufacturing costs. There was a problem.

  In Conventional Example 2, a part of the laser beam branched by the beam splitter 59 is received by the first light receiving element and the second light receiving element together, and is not completely branched into three. .

  Conventional Example 3 has a problem that the optical component has a pentagonal complicated shape.

  Further, it is necessary to attach a transmissive film having almost no reflectivity to one surface across the corner and a reflective film having a reflectivity of about 1% on the other surface, resulting in a complicated manufacturing process.

  Furthermore, since the laser beam is incident on the corner of the optical component, there is a problem that light is easily scattered at the corner, and the expected branching ratio cannot be obtained.

  The present invention has been made to solve the above-described problems. A laser device and a semiconductor laser module, which can reduce the size of the device, reduce power consumption and manufacturing cost, have a simple structure, and are easy to manufacture. The purpose is to provide.

The laser device of the present invention is a laser device having a light emitting element, an optical component that receives laser light emitted from the light emitting element and branches into a plurality of branched lights, and a light receiving element.
The optical component reflects a part of the incident laser beam and diverges and emits the first branched light as a first branched light, and a part of the laser light transmitted through the first surface. A second surface that reflects and branches as the second branched light, transmits a part of the laser light and branches as the third branched light, and a second light that transmits and emits the second branched light. A surface and a third surface that transmits and emits the third branched light,
The light receiving element includes a first light receiving element that receives the first branched light, and a second light receiving element that receives the second branched light ,
The optical component includes the first surface and the second surface, and includes a first prism having a triangular shape in plan view and a second prism having a third surface and having a triangular shape in plan view. ,
The inner surface is formed by bonding the first prism and the second prism so that the whole becomes a square in plan view,
The first surface is the rectangular surface that serves as an incident surface of the laser light, and the inner surface is a bonding surface of the first prism and the second prism,
The optical component is incident such that an angle formed by the optical axis of the laser beam and the first branched light and an angle formed by the optical axis of the laser beam and the second branched light are both acute angles. The first surface is inclined with respect to the optical axis of the laser beam.
It is characterized by this.

A reflective film having a reflectance of 1 to 2% may be formed on each of the first surface and the inner surface.

  An optical filter that selectively transmits laser light of a predetermined wavelength may be disposed between the optical component and the second light receiving element.

  An optical fiber for guiding the third branched light and sending it out may be arranged.

  The semiconductor laser module of the present invention includes an emission wavelength of the light emitting element based on the amount of light received by the laser device, a package housing the laser device, and the first light receiving element and the second light receiving element. And control means for controlling.

  According to the present invention, the following excellent effects can be obtained.

  (1) Since the laser beam can be branched into three branched lights by one optical component, the number of components can be reduced, and the installation space for the components can be reduced. Manufacturing costs can be reduced.

  (2) The laser beams received by the first light receiving element and the second light receiving element can be completely branched.

  (3) Since the laser beam is incident on the first surface of the optical component and is not incident on the corner portion, the light is not scattered and a desired branching ratio can be obtained.

  (4) Since the optical component can be formed by bonding two prisms, the structure is simple and the manufacture is easy.

It is explanatory drawing which shows an example of the laser apparatus and semiconductor laser module which concern on the example of embodiment of this invention. (A) And (B) is explanatory drawing which shows an example of the conventional semiconductor laser module.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing an example of a laser device and a semiconductor laser module according to an embodiment of the present invention.

  As shown in FIG. 1, a laser apparatus S according to an embodiment of the present invention includes a light emitting element 1 and an optical component 2 (beam) that receives laser light emitted from the light emitting element 1 and branches it into three branched lights. Splitter), the first light receiving element 3 and the second light receiving element 4, and the optical fiber 5.

  The light emitting element 1 is a laser diode (semiconductor laser element) that emits laser light, and is fixed on a light emitting element mounting table 7 fixed on the surface of the base 6.

  Between the light emitting element 1 and the optical component 2, a parallel lens 8 that collimates the laser light emitted from the light emitting element 1 and an isolator 9 that blocks the reflected return light from the optical component 2 are disposed. .

  The optical component 2 is formed in a square shape (substantially square in the example of FIG. 1) by bonding the bottom surface of the triangular first prism 10 and the bottom surface of the triangular second prism 11 together.

  The optical component 2 reflects a part of the incident laser light and diverges and emits the first branched light L1 as a first branched light L1 and a part of the laser light transmitted through the first surface 10a. The inner surface 2a (the bottom surfaces of the first prism 10 and the second prism 11) that reflects and branches as the second branched light L2, and transmits a part of the laser light and branches as the third branched light L3. And a second surface 10b that transmits and emits the second branched light L2, and a third surface 11a that transmits and emits the third branched light L3.

  The optical component 2 is positioned so that the laser light is incident on the first surface 10a at a desired angle.

  A reflective film having a reflectance of 1 to 2% is formed on each of the first surface 10a and the inner surface 2a.

  The first light receiving element 3 receives the first branched light L1, and the second light receiving element 4 receives the second branched light L2.

  An optical filter 12 such as an etalon that selectively transmits laser light having a predetermined wavelength is disposed between the optical component 2 and the second light receiving element 4.

  The optical fiber 5 guides the third branched light L3 emitted from the third surface 11a of the optical component 2 and sends it out.

  A condensing lens 13 for condensing the third branched light L3 and optically coupling it to the optical fiber 5 is disposed between the optical component 2 and the optical fiber 5.

  Next, the operation of the laser apparatus S according to the embodiment of the present invention will be described.

  Laser light emitted from the light emitting element 1 is made parallel by the parallel lens 8, passes through the isolator 9, and is incident on the first surface 10 a of the optical component 2.

  A part of the incident laser light is reflected by the first surface 10a, and is branched and emitted as the first branched light L1. The first branched light L 1 is received by the first light receiving element 3.

  A part of the laser light transmitted through the first surface 10a is reflected by the inner surface 2a and branched as the second branched light L2, and a part of the laser light is transmitted as the third branched light L3. Branch off.

  The second branched light L <b> 2 is emitted through the second surface 10 b and is received by the second light receiving element 4 through the optical filter 12.

  The third branched light L3 is emitted through the third surface 11a, collected by the condenser lens 13, incident on the optical fiber 5, and transmitted to the outside.

  A semiconductor laser module M according to an embodiment of the present invention includes the laser device S, a package 14 that houses the laser device S, and a control unit 15 (control means).

  The control unit 15 controls the light output to be constant by adjusting the amount of drive current to the light emitting element 1 by, for example, an APC circuit based on the monitoring result by the first light receiving element 3.

  In addition, the control unit 15 monitors the wavelength of the laser light from the amount of light received by the first light receiving element 3 and the second light receiving element 4, and based on the monitoring result, for example, by a temperature adjusting unit such as a Peltier module By controlling the temperature of the light emitting element 1, control is performed so as to maintain a predetermined emission wavelength.

  According to the embodiment of the present invention, the laser light can be branched into three branched lights by one optical component 2, so that the number of components can be reduced and the installation space for the components can be reduced, so that the apparatus can be downsized and the temperature can be adjusted. Therefore, it is possible to reduce power consumption and manufacturing cost.

  Further, the laser beams received by the first light receiving element 3 and the second light receiving element 4 can be completely branched.

  In addition, since the laser beam is incident on the first surface 10a of the optical component 2 and is not incident on the corner portion, the light is not scattered and a desired branching ratio can be obtained.

  Furthermore, since the optical component 2 can be formed by bonding the bottom surfaces of the two triangular prisms 10 and 11, the structure is simple and the manufacturing is easy.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical matters described in the claims. The shapes of the optical component 2 and the prisms 10 and 11 are not necessarily limited to those of the embodiment, and may be other shapes.

  The present invention is used in, for example, a semiconductor laser module used as a signal light source in optical communication, a pumping light source of an optical fiber amplifier, or the like.

S: laser device M: semiconductor laser module L1: first branched light L2: second branched light L3: third branched light 1: light emitting element 2: optical component 2a: inner surface 3: first light receiving element 4 : Second light receiving element 5: optical fiber 6: base 7: light emitting element mounting table 8: parallel lens 9: isolator 10: first prism 10 a: first surface 10 b: second surface 11: second Prism 11a: 3rd surface 12: Optical filter 13: Condensing lens 14: Package 15: Control part (control means)

Claims (5)

In a laser device having a light emitting element, an optical component that receives laser light emitted from the light emitting element and branches into a plurality of branched lights, and a light receiving element,
The optical component reflects a part of the incident laser beam and diverges and emits the first branched light as a first branched light, and a part of the laser light transmitted through the first surface. A second surface that reflects and branches as the second branched light, transmits a part of the laser light and branches as the third branched light, and a second light that transmits and emits the second branched light. A surface and a third surface that transmits and emits the third branched light,
The light receiving element includes a first light receiving element that receives the first branched light, and a second light receiving element that receives the second branched light ,
The optical component includes the first surface and the second surface, and includes a first prism having a triangular shape in plan view and a second prism having a third surface and having a triangular shape in plan view. ,
The inner surface is formed by bonding the first prism and the second prism so that the whole becomes a square in plan view,
The first surface is the rectangular surface that serves as an incident surface of the laser light, and the inner surface is a bonding surface of the first prism and the second prism,
The optical component is incident such that an angle formed by the optical axis of the laser beam and the first branched light and an angle formed by the optical axis of the laser beam and the second branched light are both acute angles. The first surface is inclined with respect to the optical axis of the laser beam.
A laser device characterized by that. 2. The laser device according to claim 1, wherein a reflection film having a reflectance of 1 to 2% is formed on each of the first surface and the inner surface .   3. The laser device according to claim 1, wherein an optical filter that selectively transmits laser light having a predetermined wavelength is disposed between the optical component and the second light receiving element.   4. The laser device according to claim 1, wherein an optical fiber that guides the third branched light and transmits the third branched light to the outside is disposed. 5. The laser device according to any one of claims 1 to 4, and
A package for housing the laser device;
Control means for controlling the emission wavelength of the light emitting element based on the amount of light received by the first light receiving element and the second light receiving element;
A semiconductor laser module comprising:

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