JPH03238407A - Plug type optical module - Google Patents

Abstract

PURPOSE:To obtain the optical module which can be easily handled and is inexpensive by forming the module to a plug type which internally houses a fiber having an easy tendency to breakage and is projected with an optical window. CONSTITUTION:An optical semiconductor element 1, a lens 2 and the optical fiber 3 are built and arranged in this order into a series of supports 6, 7, 8. A 1st ferrule 4 mounted to one end of the optical fiber 3 and a 2nd ferrule 5 mounted to the other one end are provided. The 1st ferrule 4 is so polished that the end face of the optical fiber 3 inclines and the 2nd ferrule 5 is formed to the plug shape to allow the connection to the other optical fiber. The problem of the breakage of the optical fiber 3 does not, therefore, arise and the easy attachment and detachment via an adapter are possible in order for connection to the other optical fiber. Since the ferrule 5 projects to the front end of the plug, stains are easily removable even when the stains stick to the fiber. The optical module of the low cost which can be easily connected particularly to the optical fiber and can be easily handled is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical semiconductor light-emitting and light-receiving module for communications, and particularly to a plug-type optical module that facilitates connection to an optical fiber.

[Conventional technology]

Conventionally, as an optical module connected to an optical fiber, a pigtailed module or a receptacle type module has been used.

FIG. 2 is a schematic diagram of an example of a conventional optical module with a pigtail, in which a ferrule 13 is attached to the tip of an optical fiber 14, and a selfoc lens 12
A laser diode 11 is provided via.

FIG. 3 is a partial cross-sectional view schematically showing an example of a conventional glue Sebutahal type module. The ferrule receiver has a configuration in which the tip of a ferrule 25 attached to a portion 23 faces the laser diode 11 via a SELFOC lens 12, and laser light passes between them.

[Problem to be solved by the invention]

The conventional pigtailed module described above has a thin and long pigtail (optical fiber 14), and this optical fiber 4 is easily broken and difficult to handle. In this case, optical connectors had to be attached or welding required, resulting in high costs.

In addition, in the case of a receptor-full type modular LD module, there is a problem in that the reflected light from the ferrule tip 23 of the connected partner returns to the laser diode 11, making the output of this laser diode unstable. Since the ferrule 25 is located at the back of the hole into which it is inserted, it is difficult to remove the dirt when it becomes dirty, and the problem is that the coupling loss increases.

The purpose of the present invention is to eliminate these drawbacks, and by creating a plug type in which a fiber that easily breaks is housed inside and a protruding optical window, it is easy to handle and inexpensive, and the output is stabilized. The objective is to provide an optical module that reduces loss.

[Means to solve the problem]

The plug-type optical module of the present invention has a structure in which an optical semiconductor element, a lens, and an optical fiber are housed in a series of supports and arranged in this order, a first ferrule attached to one end of the optical fiber, and a first ferrule attached to one end of the optical fiber. and a second ferrule attached to the other end of the optical fiber, the first ferrule is polished so that the end surface of the optical fiber is oblique, and the second ferrule is attached to the other end of the optical fiber. It is characterized by being shaped like a plug so that it appears to be connected.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

In the figure, 1 is a laser diode, 2 is a SELFOC lens, 3 is a single mode fiber, 4 is a ferrule whose end is obliquely cut and polished, and 5 is a standard ferrule for an F'C-PC connector.

The laser diode 1 is housed inside the stem 6 and welded to the lens holder 7 using a YAG laser.

On the other hand, a portion A in which the ferrule 5 is held has a shape similar to that of an FC connector, and a ferrule holder 8 is screwed to this portion.

In this configuration, the light emitted from the laser diode 1 is focused by the SELFOC lens 2, but this focused spot is finely adjusted by applying it to the cladding part of the optical fiber 3 located in the center of the ferrule 4, and the light is focused by the SELFOC lens 2. The spaces between the holder 8 and the slide ring 9 and between the ferrule holder 5 and the slide ring 9 are welded and fixed using each YAG laser.

The operation of the plug type optical module assembled in this manner will be explained.

Light emitted from a laser diode 1 is focused onto a cladding portion of an optical fiber 3 by a SELFOC lens 2. Since the tip of the ferrule 4 is polished at an angle of about 7 degrees, the light reflected from the end surface does not return to the laser diode 1, and its optical output is stable. The light that has entered the optical fiber is output from the ferrule 5, and this light is normally transmitted via an FC adapter to an FC connector attached to the other end of the optical fiber.

As for the characteristics of this example, the following results were obtained. The optical coupling loss was about -10 dB on average, and the change in coupling efficiency due to temperature difference was less than ±0.5 dB in the range of ±35°C with respect to 25°C.

Furthermore, the repeatability was all within ±1 dB of coupling loss when repeated 100 times.

Further, as another embodiment of the present invention, a laser diode 1
Optical semiconductor devices such as LEDs, APDs, and PIN-PDs can be used in place of LEDs, ball lenses or microlenses formed on the cap of can cases can be used in place of selfoc lenses, and multimode fibers can be used as optical fibers. Also, the shape of the plug is DIN instead of FC connector.
Connectors, ST connectors, etc. can be used, and solder can also be used to fix the stem and lens holder.

〔Effect of the invention〕

As explained above, in the present invention, since the optical fiber is housed inside the support, there is no problem of breakage, and in order to connect to another optical fiber, it can be easily attached and detached via an adapter, and the plug can be easily connected to another optical fiber. Since the ferrule protrudes from the tip of the fiber, it can be removed even if it gets dirty, and in the case of an LD module, the reflection from the end of the fiber that couples the light is obliquely cut so that it has no effect at all.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a plug-type optical module of the present invention, FIG. 2 is a schematic diagram showing the configuration of an example of a conventional optical module with a pigtail, and FIG. 3 is a diagram of a conventional glue-type optical module. FIG. 2 is a schematic diagram showing an example configuration. 1.11...Laser diode, 2.12...Selfoc lens, 3.14...Optical fiber, 4...First ferrule, 5...Second ferrule, 6...Can' Package, 7... Lens holder, 8... Ferrule holder, 9... Slide ring, 13...
Ferrule, 23... Ferrule receiver part, 24...
laser beam.

Claims (1)

[Claims] An optical semiconductor element, a lens, and an optical fiber are housed in a series of supports and arranged in this order, a first ferrule attached to one end of the optical fiber, and a first ferrule attached to the other end of the optical fiber. 2 ferrules, the first ferrule is polished so that the end surface of the optical fiber is oblique, and the second ferrule is shaped like a plug so that it is connected to another optical fiber. A plug-type optical module featuring: