JPH07104153A - Laser module with optical isolator - Google Patents

Abstract

PURPOSE:To provide a small-sized module with optical isolator. CONSTITUTION:A chip carrier 5 with a fixed laser element 7 is fixed on a mount base 3 for arranging a lens 8, the optical isolator 10, a monitor photodiode 4 and a thermistor 9 through a heat sink 6 by soldering. Next, the mount base 3 is fixed on Peltier element 2 by soldering. Thereafter, a reflection mirror 14 is inserted in a reflection mirror mount part on the mount base 3, and after adjusting reflected laser light with reference to a position for fixing an optical fiber, the reflection mirror 14 is fixed by applying resin or solder. Next, after leaving a package 1 in the dry air or in an atmosphere of nitrogen, the package 1 is sealed in an airtight state. Thereafter, the optical fiber 13 fixed in a ferrule 12 is inserted through the outside hole of a window glass 11, and then, the fiber 13 is fixed at an optimum position by applying YAG welding while adjusting optical coupling. By having such a constitution, the small-sized module equipped with optical isolator is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser module used as a light source for optical fiber communication.

[0002]

2. Description of the Related Art When a semiconductor laser is used as a light source for optical communication, the semiconductor laser is modularized in order to easily extract the laser output light, and the laser output light can be easily obtained from an optical fiber called a pigtail.

A conventional module with an optical isolator will be described below. FIG. 3 shows the configuration of a conventional module. In FIG. 3B, the semiconductor laser 7
Is fixed to the mount base 3 via a heat sink 6 and a chip carrier 5. At the same time on the mount base 3, a condenser lens 8, a monitor photodiode 4, and a thermistor 9
Also, the optical isolator 10 is fixed. Mount base 3
Is fixed to the package 1 via a Peltier device 2. The package 1 has a window glass 11, and an optical fiber 13 fixed in a ferrule 12 is fixed to the outside of the window glass 11.

[0004]

However, in the module configured as described above, the distance between the lens and the optical fiber is limited by the performance of the lens, which makes it very difficult to reduce the size of the module. Is. Also, in order to multi-branch the output light from this module, it is necessary to connect an optical coupler to the optical fiber. At this time, the return light due to the reflection at the optical coupler or the etalon formed between the reflection points may adversely affect the transmission characteristics.

Therefore, an object of the present invention is to reduce the size of the module and to make a plurality of outputs from the module itself to reduce the number of optical couplers and the reflection points in the transmission line. .

[0006]

In order to solve the above problems, the present invention provides a semiconductor laser device fixed on a chip carrier via a heat sink and an output light from the laser device. In a module with an optical isolator comprising a lens, a polarizer, a Faraday rotator, and an optical isolator in which an analyzer is sequentially arranged on the optical axis, and an optical fiber fixed in a ferrule, output light from the optical isolator By having a reflecting mirror for coupling the optical fiber to the optical fiber, the required optical path length is secured in a narrow space and the module size is reduced.

Further, according to the present invention, a semiconductor laser device fixed on a chip carrier via a heat sink, a first lens for collimating output light from the laser device, a polarizer, a Faraday rotator, In an optical isolator module comprising an optical isolator in which analyzers are sequentially arranged on the optical axis, a second lens for collecting the parallel light, and a plurality of optical fibers fixed in a ferrule, The laser module itself is provided with a plurality of reflecting mirrors for causing the light emitted from the optical isolator to enter the second lens and to be coupled to the optical fiber.

[0008]

In the above means, the optical path length can be adjusted by effectively widening the narrow space by reflection, so that the coupling distance, which conventionally regulates the size of the package, can be sufficiently secured to reduce the size of the package. Can be realized.
Further, since the output light can be multi-branched by using the reflection, it is possible to reduce the number of optical components in the transmission path (reduction of reflection points) and reduce the deterioration of the transmission characteristics.

[0009]

EXAMPLES Specific examples of the present invention will be described in detail below. First, the first embodiment will be described.

(Embodiment 1) FIG. 1 shows a block diagram viewed from above. A chip carrier 5 to which a laser element 7 is fixed is fixed to a mount base 3 on which a lens 8, an optical isolator 10, a monitor photodiode 4 and a thermistor 9 are arranged via a heat sink 6 by soldering.

Next, the mount base 3 is fixed on the Peltier device 2 by soldering, and then the laser device 7 is wired by wire bonding so that a current can be applied. Coupling laser light to an optical fiber generally requires adjustment in three directions. Here, the reflecting mirror 14 is inserted into the reflecting mirror mounting portion on the mount table 3, and the reflected laser light is adjusted in the vertical direction within the package 1 with respect to the position where the optical fiber is fixed. Alternatively, it is fixed with solder. The other two directions can be adjusted by the amount of insertion into the package when fixing the optical fiber.

A window glass 11 is attached to the package 1, and the fiber is inserted from the outside thereof. Next, the package is left in a dry air or nitrogen atmosphere and then hermetically sealed. After that, the optical fiber 13 fixed in the ferrule 12 is inserted through the hole on the outside of the window glass 11 and fixed by YAG welding at an optimum position while adjusting the coupling of light. With such a configuration, the light emitted from the laser is reflected by the reflecting mirror 14 and input to the optical fiber 13.

The point of the construction of this embodiment is that the optical axis of the light emitted from the laser and the optical axis of the optical fiber 13 do not coincide with each other, and the laser element 7, the lens 8, the optical isolator 10 and the optical fiber 13 are arranged between them. This is the point where reflector 14 is placed. With such a configuration, the space in the package can be effectively used, and thus a module with an optical isolator smaller than the conventional one can be obtained.

(Second Embodiment) Next, a second embodiment will be described. FIG. 2 shows a configuration diagram viewed from above.

As in the first embodiment, a chip carrier 5 in which a laser element 7 is fixed via a heat sink 6 to a mount base 3 on which a first lens 8, an optical isolator 10, a monitor photodiode 4 and a thermistor 9 are arranged. After being fixed with solder, the mount base 3 is fixed with solder on the Peltier device 2, and wiring is performed by wire bonding so that a current can be applied to the laser device 7.

In this embodiment, the output light from the laser is first
Since the parallel light is made by the lens 8 of No. 1, unlike the first embodiment, the optical path length after passing through the first lens 8 is not limited. Therefore, the light can be branched by a large number of reflections within a range in which the reduction of the light output is allowable. In this embodiment, a half mirror 15 is arranged between the reflecting mirror 14 and the second lens 16 in order to multi-split the light. First, mount stand 3
After inserting the reflecting mirror 14 in the upper reflecting mirror mounting portion and the half mirror 15 in the half mirror mounting portion, and adjusting the reflected laser light in the vertical direction within the package 1 with respect to the position for fixing the optical fiber, the reflecting mirror 14 and the half mirror 15 are fixed with resin or solder.

Next, the package 1 is left in a dry air or nitrogen atmosphere and then hermetically sealed. After that, the optical fiber 13 fixed in the ferrule 12 is inserted through the hole on the outside of the window glass 11 and fixed by YAG welding at an optimum position while adjusting the coupling of light. The point of the configuration of this embodiment is that the optical axis of the light emitted from the laser does not coincide with the optical axis of the optical fiber 13 as in the first embodiment, and the laser element 7,
The point is that a reflecting mirror (half mirror) 15 is placed between the lens 8, the optical isolator 10 and the optical fiber 13, and that the laser beam is made parallel by the first lens 8.

With such a structure, since the light branching that has conventionally been performed outside the package can be performed inside the module package, the number of components in the optical transmission line can be reduced, and the optical transmission line with low reflection can be obtained. Can be configured.

[0019]

As described in detail above, according to the present invention, the following effects can be obtained.

A semiconductor laser device fixed on a chip carrier via a heat sink, a lens for collecting output light from the laser device, a polarizer, a Faraday rotator, and an analyzer are sequentially arranged on the optical axis. In an optical isolator-equipped module comprising an optical isolator and an optical fiber fixed in a ferrule, the module has a reflection mirror for coupling the output light from the optical isolator to the optical fiber, compared to the conventional module. The size can be reduced. Further, a multi-branch module can be configured by using a first lens for making the output light from the laser element parallel light and a second lens for condensing the parallel light. .

[Brief description of drawings]

FIG. 1 is a module configuration diagram of a first embodiment of the present invention.

FIG. 2 is a module configuration diagram of a second embodiment of the present invention.

[FIG. 3] Conventional module configuration diagram

[Explanation of symbols]

 1 Package 2 Peltier element 3 Mount base 4 Monitor photodiode 5 Chip carrier 6 Heat sink 7 Semiconductor laser 8 Lens 9 Thermistor 10 Optical isolator 11 Window glass 12 Ferrule 13 Optical fiber 14 Reflector 15 Half mirror 16 Lens

Claims (2)

[Claims] 1. A semiconductor laser device fixed on a chip carrier via a heat sink, a lens for collecting output light from the laser device, a polarizer, a Faraday rotator, and an analyzer on the optical axis. A module with an optical isolator comprising an optical isolator sequentially arranged and an optical fiber fixed in a ferrule, characterized by having a reflecting mirror for coupling the output light from the optical isolator to the optical fiber. Laser module with optical isolator. 2. A semiconductor laser device fixed on a chip carrier via a heat sink, a first lens for collimating output light from the laser device, a polarizer, a Faraday rotator, and an analyzer. A module with an optical isolator comprising an optical isolator sequentially arranged on an optical axis, a second lens for condensing the parallel light, and an optical fiber fixed in a ferrule, and emitted from the optical isolator. A laser module with an optical isolator, comprising: a plurality of reflecting mirrors for causing the light thus made incident on the second lens to be coupled to the optical fiber.