JPH0281008A - Semiconductor laser module - Google Patents

Abstract

PURPOSE:To constitute a semiconductor laser module to a removable connector type so as to reduce the size and cost of the module by using a glass spacer having a polished normal surface on one side and a polished slope on the other side as the stopper of a receptacle. CONSTITUTION:A receptacle 14 is fixed to a holder 19 holding an ID package 20 and one piece of lens 18 by means of the outer peripheral thread of a stopper 16. The stopper 16 is constituted of a glass spacer 15 having a polished normal optical surface on one side and a polished optical slope surface on the other side and the slope is used for preventing reflected ray of light to a light source from near ends. The front end of the ferrule of an optical connector is closely adhered to the normal surface of the spacer 15. As a result, this semiconductor laser module can be constituted to a removable connector type having a simple structure and the size and cost of the module can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light source for optical communication, and particularly to a semiconductor laser module having a function of efficiently coupling a semiconductor laser element and an optical fiber.

[Conventional technology]

In general, semiconductor laser modules have already been put into practical use as light sources for optical communications, and the basic configuration as shown in FIG. 3 is widely known. That is, this semiconductor laser module is a semiconductor laser (hereinafter referred to as LD) pellet 1.
The structure is such that the beam emitted from the optical fiber 3 is focused by a lens 2 onto the end face of the optical fiber 3. By the way, since LDs have the characteristic that reflection noise is generated due to reinjection of the near-end reflected light, and the modulation characteristics are deteriorated, the near-end reflected light (broken line) is suppressed by obliquely polishing the end face of the optical fiber 3. There is.

FIG. 4 shows an example of the structure of a conventional semiconductor laser module. An LD package 6 that accommodates the LD pellet 1 is fixed to one end of the holder 5 that accommodates the ball lens 4, and a ferrule 8 in which an optical fiber core wire 7 is terminated is inserted from the other end, and the holder 5 is secured with a screw 9. 〆5
permanently fixed. The end face of this ferrule 8 is obliquely polished for the reason described above.

[Problem to be solved by the invention]

As described above, in the past, oblique polishing of the ferrule 8 was required, and for this reason, it was not possible to adopt a structure in which a general-purpose standard connector whose tip was polished at a right angle could be directly attached and detached. That is, as shown in FIG. 3, the conventional semiconductor laser module has a pigtail structure in which one end of the optical fiber core wire 7 is permanently fixed to the semiconductor laser module and the other end has a connector.

By the way, this semiconductor laser module is mounted on a circuit board together with a drive circuit, a digital circuit, etc., and constitutes an optical panel. Conventionally, semiconductor laser modules are pigtail-shaped, so the connector at the end of the pigtail is connected to an adapter mounted on the side of the optical panel, and after processing the excess length of the optical fiber, the semiconductor laser module body is mounted on the circuit board. It is now possible to do so. Therefore, this semiconductor laser module main body cannot be mounted on the side surface of an optical panel. That is, there was a drawback that the degree of freedom in mounting position was low. Another drawback is that it requires mounting space equal to the length of the optical fiber. Furthermore, since the connector cannot be attached to or detached from the semiconductor laser module main body, parts such as an adapter, an optical connector at the tip of the pigtail, and a ferrule inside the semiconductor laser module are required, resulting in high costs. Furthermore, since the length of the optical fiber varies depending on the design of the optical panel, there is also the drawback of poor versatility.

The object of the present invention has been made in view of the above-mentioned drawbacks, and is a semiconductor laser module that can increase the degree of freedom in mounting position on an optical panel, reduce the mounting space, further reduce costs, and is full of versatility. Our goal is to provide the following.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention includes an LD element;
In a semiconductor laser module that includes one lens that is housed and held in a holder and that focuses the output beam of this LD element, and a receptacle that is fixed to this holder, the stopper of this receptacle has one optical surface that is It consists of a glass spacer whose optical surface is polished at a right angle and whose optical surface is polished at an angle, and the ferrule tip of the optical connector that is fitted into this receptacle is configured so that it comes into close contact with one optical surface of the glass spacer. be.

[Effect]

In this way, the present invention uses a glass spacer with one optical surface polished at right angles and the other optical surface polished diagonally as a stopper of a receptacle to which a connector can be directly attached and detached. With this configuration, a connector-removable semiconductor laser module can be realized. the result,
The adapter, the connector at the end of the pigtail, and the ferrule inside the semiconductor laser module are no longer required, making it possible to significantly reduce the cost of the optical panel.

Further, since there is no pigtail portion, the mounting space can be reduced, the degree of freedom in mounting position on the optical panel can be increased, and versatility does not deteriorate due to changes in the pigtail length.

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 is a schematic configuration diagram showing the basic configuration of a semiconductor laser module according to the present invention. This semiconductor laser module includes an LD pellet 10, a lens 11 that converges the output beam of the LD pellet 10, and a receptacle 14 in which a ferrule 13 in which an optical fiber 12 is terminally processed is illuminated, and the ferrule 13 can be attached and detached. This is a connector-removable semiconductor laser module characterized in that, in this configuration, a glass spacer 15 whose optical palm surfaces are not parallel to each other is used as a stopper of a receptacle 14.

When a PC (physical contact) type connector, which has recently become common, is inserted into the receptacle 14, the end face of the optical fiber 12 comes into close contact with the glass spacer 15, and the PC
state. On the other hand, the optical fiber 1 of the glass spacer 15
Since the optical surface opposite to 2 is formed obliquely to the optical axis, reinjection of reflected light (broken line) into the LD is suppressed. Therefore, according to the present invention, it is possible to realize a semiconductor laser module in which the connector can be directly attached and detached, and the reflection noise is small.

Now, the specific structure of the semiconductor laser module according to the present invention will be explained using FIG. The stopper 16 of the receptacle 14 includes a metal pipe 17 provided with a screw on the outer periphery, and a glass spacer 1 provided inside the metal pipe 17.
One end surface 15a of the glass spacer 15 on the fiber ferrule side is polished to a spherical surface at a right angle, and the other end surface 15b is polished obliquely. The holder 19 housing the ball lens 18 and the receptacle 14 are fixed to each other via a screw on the outer periphery of the stopper 16.

After the optical axis of the LD package 20 is adjusted with respect to the optical fiber core of the PC connector connected to the receptacle 14, the LD package 20 is fixed to the holder 19 by spot welding using a YAG laser or the like. In the experimental example, glass spacer 1
It was confirmed that the reflection at the close contact between PC connector 5 and the tip of the PC connector had a return loss of 35 dB or more, which was comparable to the reflection at the connection between two PC connectors, and was sufficiently small for practical use.

〔Effect of the invention〕

As explained above, the semiconductor laser module according to the present invention has a structure in which a glass spacer with one optical surface polished at a right angle and the other optical surface polished at an angle is used as a stopper for a receptacle to which a connector can be directly attached and detached. By doing this, it is possible to realize a connector-removable semiconductor laser module with a simple configuration. As a result, compared to conventional pigtail semiconductor laser modules, an adapter, a connector at the end of the pigtail, and a ferrule within the semiconductor laser module can be eliminated, thereby significantly reducing the cost of the optical panel. In addition, since there is no pigtail part, the mounting space can be reduced, the degree of freedom in mounting position on the optical panel can be increased9, and furthermore, it has various effects such as being able to reliably prevent a decrease in versatility due to changes in the pigtail length. .

Therefore, the semiconductor laser module of the present invention is likely to be widely put into practical use, and its industrial value is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the basic configuration of a semiconductor laser module according to the present invention, FIG. 2 is a sectional view showing an example of a specific configuration of a semiconductor laser module according to the present invention, and FIG. 3 is a conventional configuration diagram. FIG. 4 is a schematic configuration diagram showing the basic configuration of a conventional semiconductor laser module, and FIG. 4 is a sectional view showing an example of a specific configuration of a conventional semiconductor laser module. lO...LD pellet, 11...lens, 12...optical fiber, 13...ferrule, 14...receptacle, 15... ...Glass spacer, 15a... One end surface, 15b... Other end surface, 16... Stopper, 18...
・Ball lens, 19...Holder, 20...
・LD package. Applicant: NEC Corporation Agent
Patent attorney Umeo Yamauchi Figure 1

Claims (1)

[Claims] a semiconductor laser element; and at least one element that is housed and held in a holder and that focuses an emitted beam of the semiconductor laser element.
In a semiconductor laser module including a lens and a receptacle fixed to the holder, the stopper of the receptacle is a glass spacer with one optical surface polished at a right angle and the other optical surface polished at an angle. 1. A semiconductor laser module characterized in that the ferrule tip of an optical connector fitted into the receptacle is in close contact with one optical surface of a glass spacer.