JPH0927634A - Optical semiconductor module device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the deviation of the position of a light-emitting element from the position of a light-receiving element and to grasp accurately the intensity of light, which is transmitted to an optical fiber. SOLUTION: In an optical semiconductor module device, which has a package 15 which is connected with an optical fiber 21, a light-emitting element 9 to emit a laser beam which is transmitted to the fiber 21, a light-receiving element 11, which receives the laser beam emitted from the element 9, and a substrate 3 for installing the elements 9 and 11, the elements 9 and 11 are installed on the same plane on the surface of the substrate 3 via a mounting material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor module device used in an optical communication system.

[0002]

2. Description of the Related Art Optical fiber communication is one of dielectric lines and optical waveguides for the purpose of transmitting visible light or near infrared light. The optical fiber has a circular cross section, has a higher refractive index at the center than at the periphery, and is designed to confine light within the fiber. There are single-core mode fibers having a diameter of several μm at the center and multicore mode fibers having a diameter of several tens of μm, and silica glass is often the main component. It is used as a transmission path for optical communication and laser measurement, and is used as a sensor for temperature, pressure, sound waves, etc.

A semiconductor laser is used as a light source for optical fiber communication. A semiconductor laser is a laser utilizing recombination emission of a semiconductor, and oscillates mainly in the visible to near infrared region. As a method of forming a pair of electron and hole, an injection laser in which a carrier is injected by applying a forward voltage to a PN junction is generally used, and there are also optical erection and electron impact. When a current is passed in the forward direction of the laser diode, laser light is emitted when the current value exceeds a certain value. This laser oscillation start current is a threshold current.

Further, the pair of end faces of the chip are mirror-finished to form a laser resonator. Light is amplified in the process of reciprocating inside the resonator and is extracted to the outside of the chip. Since the laser diode mainly has a light emitting process called stimulated emission, it is possible to obtain light in which wavelengths and phases are perfectly aligned. Therefore, it has excellent directivity and energy concentration.

FIG. 3 shows a conventional optical semiconductor module device, for example, a light emitting element 109 for emitting laser light and a light receiving element for receiving emitted light in a package 115 made of Kovar.
111 and a metal substrate 103 on which a temperature sensing element 105 (Peltier element) that senses the temperature of the light emitting element is installed, a lens 113 that collects emitted light, and a cooling element 101 that installs the substrate 103.
Having. The light-emitting element 109 and the light-receiving element 111 are L-shaped as shown in FIG. 3, and the light-emitting element 109 and the light-receiving element 111 are sensed so as not to exceed a certain temperature, and at the same time, the substrate on which the light-emitting element 109 and the light-receiving element 111 are installed. Play a role of. The cooling element keeps the temperature of the light emitting element 109 constant, and the elements inside these packages are called internal optical system equipment.

Further, the light emitting device 10 is provided outside the package 115.
A fiber holder 117 for holding the optical fiber 121 for transmitting the emitted light of 9 and a lens 119 for optical coupling into the optical fiber 121 installed in the fiber holder 117 are installed, and these external elements are connected to the external optical device. System equipment.

FIG. 3B is a diagram showing the positional relationship between the light emitting element 109 and the light receiving element 111 in detail. The light emitting element 109 is mounted on the temperature sensing element 105 by the mount material 107. The positions of the light emitting element 109 and the light receiving element 111 are
In consideration of the radiation angle of 9, the shape of the light receiving element 111, etc., it is necessary to install them at an optically optimal position. Conventionally, the light-emitting element 109 and the light-receiving element 111 cannot be mounted on the same plane, so the positions of the light-emitting element 109 and the light-receiving element 111 will shift when aligning the target installation position and each element, and accurate light emission Could not monitor the strength of. Therefore, the intensity of the emitted light transmitted through the optical fiber cannot be accurately grasped.

[0008]

In the optical semiconductor module, an internal optical system of the package and an external optical system composed of an optical fiber are supported via the package. The intensity of light emitted from the light emitting element to the external optical system is monitored by the light receiving element. The positions of the light emitting element 109 and the light receiving element 111 need to be set at optically optimal positions in consideration of the radiation angle of the light emitting element 109, the shape of the light receiving element 111, and the like. Conventionally, the light emitting element and the light receiving element have not been installed on the same plane, so that it is necessary to change the installation surface when mounting. Therefore, there is a possibility that the preset installation target and the actual installation position may deviate. If the installation position is deviated, the light emitted from the light emitting element cannot be accurately measured, resulting in an error.

According to the present invention, the light emitting element and the light receiving element are mounted on the same plane so that the light emitting element and the light receiving element are not displaced in position and the intensity of the emitted light transmitted through the optical fiber can be accurately grasped. An object of the present invention is to provide an optical semiconductor module device.

[0010]

A package connected to an optical fiber, a light emitting element for emitting laser light transmitted to the optical fiber, a light receiving element for receiving light emitted from the light emitting element, a light emitting element and a light receiving element. In a semiconductor module device having a substrate on which the light emitting element and the light receiving element are mounted, the light emitting element and the light receiving element are mounted on the same plane on the surface of the substrate via a mount material. Therefore, the target positions of the light emitting element and the light receiving element can be seen at the same time.

[0011]

Since the light emitting element and the light receiving element for receiving the light emitted from the light emitting element are mounted on the same surface of the substrate surface, the target position can be confirmed in the same step. As a result, the deviation between the target position and the installation position is reduced, and the light emitted to the optical fiber can be accurately grasped.

[0012]

FIG. 1 shows an embodiment of the present invention. FIG. 1 (a) is a cross-sectional view of the optical semiconductor module device according to the present invention. For example, an optical fiber 21 for transmitting laser light, a fiber holder 17 for connecting the optical fiber 21 and the package 15 to the outside of the package 15 made of Kovar. An external optical system consisting of a cooling element 1, a light emitting element 9 and a light receiving element 11 on the cooling element 1.
And an internal optical device composed of the substrate 3 on which the lens 13 is installed. The light emitting element 9 and the light receiving element 11 for monitoring the light emitted from the light emitting element 9 are mounted on the temperature sensing element 5 (for example, Peltier element) by the mount material 7. The temperature sensing element 5 is an element that senses the light emitting element 9 so as not to exceed a certain temperature. A lens 13 that collects the light emitted from the light emitting element 9 is provided on the substrate 3. Board 3 is a package
Installed on cooling element 1 installed on the inner bottom surface of 15,
The cooling element 1 is an element for keeping the light emitting element 9 at a constant temperature so as not to exceed a certain temperature. These packages 115
The internal element is called an internal optical system device.

An optical fiber connected to the package 15
A fiber holder 17 for holding 21 and a first for optical coupling into an optical fiber 21 installed in the fiber holder 17.
2 The lens 19 and the optical fiber 21 form an external optical device.

FIG. 1B is a diagram showing in detail the positional relationship between the light emitting element 9 and the light receiving element 11. Light emitting element 9 and light receiving element 11
Are mounted on the temperature sensing element 5 by the mount material 7 on the same plane. The light emitting element 9 and the light receiving element 11 irradiate the light emitted from the light emitting element 9 to the light receiving layer 12 in the light receiving element 11, and convert the emitted light into a current. In this embodiment,
Since the impurity layer of the light receiving element 11 transmits the emitted light, the emitted light is introduced from the side surface to the light receiving layer 12 of the light receiving element 11,
It passes through the light receiving element 11 and is optically coupled to the light receiving layer 12. The thickness of the light emitting element 9 used in this embodiment is about 100 μm, and the thickness of the light receiving element 11 is about 200 μm. If the light emitting element 9 and the light receiving element 11 are placed on the same plane, the light emitted from the light emitting element 9 irradiates the light receiving layer 12 of the light receiving element 11. Therefore, the light receiving layer 12 of the light receiving element 11, the light emitting layer 10 of the light emitting element 9 and the axis of the optical fiber 21 are substantially on the same plane. However, since the emitted light irradiates the layer of the light emitting layer 12 in parallel, the irradiation amount becomes small and the converted current value becomes small. However, since the efficiency of photoelectric conversion is constant, a correct emission value can be detected if it is known in advance that the efficiency will be small.

The positions of the light emitting element 9 and the light receiving element 11 need to be set at optically optimal positions in consideration of the radiation angle of the light emitting element 9 and the shape of the light receiving element 11. In this embodiment, it is necessary that the axis of the optical fiber 21, the light emitting layer 10 of the light emitting element 9 and the light receiving layer 12 of the light receiving element 11 are on the same straight line. The light emitting element 9 is mounted on the same plane by the mount material 5. As a result, at the time of mounting, the light emitting element 9 and the light receiving element 11 can be installed on the same monitor, and the mutual alignment becomes accurate.

In this embodiment, the light receiving element is the light emitting element 9
Since it is installed on the same plane as, the internal optical system element can be downsized. FIG. 2A shows a method of mounting the light emitting element and the light receiving element shown in this embodiment. When mounting, the installation position of the light emitting element and the light receiving element is confirmed by the monitor screen 30 of the mounting device in which the surface of the substrate 32 is viewed from above. Next, looking at the monitor screen 30, the light emitting element installation area 34 and the light receiving element installation position 36 are determined, and the points are aligned. Next , a mount material (not shown) is formed on the regions 34 and 36, and the light emitting element and the light receiving element are placed on the mount material. In this embodiment, the light emitted from the light emitting element is emitted from the side surface of the light receiving element.

In this embodiment, since the same monitor screen 30 is mounted and the light emitting element and the light receiving element are installed on the same plane, there is no misalignment when the light emitting element and the light receiving element are aligned, and optical coupling is achieved. You can prevent it from weakening.

FIG. 2 (b) shows the light receiving element shown in this embodiment. For example, a photodiode is an element that converts an optical signal into an electric signal. When the emitted light enters, the electrons bound to the lattice are released and become free electrons. These electrons and holes move to the depletion layer region and generate a reverse current proportional to the intensity of the emitted light. In the light emitting device shown in this embodiment, a depletion layer is formed at the boundary surface between the P + layer 46 and the N layer (InGaAs) 40, and the N layer (InGaAs) 40 is the light receiving layer (
Light-current conversion layer).

Further, the other N layers 38, 42 and 44 have an emission wavelength of 1.55.
Since the light energy is large with respect to μm, the emitted light is substantially transmitted. Therefore, the light emitted from the side surface of the light emitting element,
It is possible to irradiate the light receiving layer.

[0020]

According to the present invention, by mounting the light emitting element and the light receiving element on the same plane, it is possible to mount the light emitting element and the light receiving element while observing the installation target of the mounting apparatus on the same plane. In addition, since the light emitting element and the light receiving element that receives the light emitted from the light emitting element are mounted on the same surface, the mounting positional relationship of each element is easy to understand, the mounting accuracy is improved, and at the time of alignment. The gap disappears. As a result, it is possible to provide an optical semiconductor module device in which the correspondence between the monitor current value and the transmitted light transmitted through the optical fiber is uniform.

[Brief description of drawings]

FIG. 1 is a sectional view (a) showing an embodiment of the present invention,
It is a detailed view (b).

FIG. 2 is a detailed view showing an embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional device.

[Explanation of symbols]

 1 101 Cooling device 3 32 103 Metal substrate 5 105 Mounting material 9 109 Light emitting element 10 Light emitting layer 11 111 Light receiving element 12 112 Light receiving layer 13 113 First lens 15 115 Package 17 117 Fiber holder 19 119 Second lens 21 121 Optical fiber 30 Monitor screen 34 Light receiving element installation position 36 Light emitting element installation position 38 N layer 40 N layer (conversion layer) 42 N layer 44 N + layer 46 P + layer 48 Protective film 50 Electrode

Claims (3)

[Claims] 1. A package connected to an optical fiber, a light emitting element for emitting laser light transmitted to the optical fiber, a light receiving element for receiving light emitted from the light emitting element, and the light emitting element and the light receiving element. In a semiconductor module device having a substrate to be installed, the light emitting element and the light receiving device are installed on the same plane of the surface of the substrate via a mounting material, and the optical semiconductor module device. 2. The light-receiving element is a photodiode semiconductor device, and the light-receiving element is formed of a light-receiving layer formed of an impurity layer and another impurity layer that transmits laser light. 1. The optical semiconductor module device according to 1. 3. The optical semiconductor module device according to claim 1, wherein the axis of the optical fiber, the light emitting layer of the light emitting element, and the light receiving layer of the light receiving element are on the same straight line.