JPH02297988A - Optical coupling system using optical semiconductor device - Google Patents

Abstract

PURPOSE:To miniaturize a device with a device sealing property and an optical coupling property of an optical coupling system both maintained by forming a cap window opening into a taper or a staircase such that it opens more widely as it goes upward, and disposing a lens across the opening. CONSTITUTION:A laser diode chip 1 and a monitoring photodiode chip 2 are fixed on a stem 5 and sealed through a cap 3 and window glass 4. The sectional shape of the cap window opening 3b is tapered such that it is more widely opened as it goes upward. A condenser lens 7 is disposed across the opening. Light 11a emanating from the chip 1 is focused by the lens 7 to enter an optical fiber 8. The incident light is set to an optimum by adjusting the position of the lens 7 through a screw 10.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to an optical coupling system using an optical semiconductor device (particularly a semiconductor laser) which has application fields such as optical communications, and particularly relates to a package structure of an optical semiconductor device. It is.

[Conventional technology]

FIG. 5 is an outline drawing showing, for example, a conventional semiconductor laser diode, in which 1 is a laser diode chip;
2 is a monitor photodiode chip, 3 is a cap,
4 is a glass window, 5 is a stem, and 6 is a reed.

The present invention exhibits its effects not in such a semiconductor laser diode itself but in a device to which the same is applied, and an application example device to which the same is applied will be described below.

FIG. 6 is a sectional view showing an optical coupling system that guides laser light to an optical fiber using the semiconductor laser diode shown in FIG. 5. In the figure, 7 is a condensing lens, 8 is an optical fiber, and 9 is a A body that supports the condensing lens 7 and the optical fiber 8; 10 is a screw that determines the position of the condensing lens 7;
a is the light emitted from the laser diode chip 1, l
lb is light that exits the condensing lens 7, enters the optical fiber 8, and propagates through the fiber.

Here, the light 11b incident on the optical fiber 8 is adjusted to an optimum amount by adjusting the position of the condensing lens 7 using the screw 10 or adjusting the position of the body 9 with respect to the camp 3. Further, after the body 9 is positioned, it is welded and fixed to the cap 3 by YAG welding or the like.

In such an application, the cap 3 not only hermetically seals the laser chip 1 but also serves as an important support for constructing the optical coupling system as described above.

[Problem to be solved by the invention]

Miniaturization of optical semiconductor devices is also an important issue, but when the conventional semiconductor laser diode shown in Figure 5 is miniaturized, the following problems occur in the optical coupling system shown in Figure 6. .

1) When the diameter of the window (opening) of the cap becomes smaller, the adjustment movable range of the lens 7 becomes smaller when an optical coupling system as shown in FIG. 6 is configured. In other words, the optical coupling characteristics deteriorate.

2) In order to prevent the above, if only the diameter of the window portion is made the same as the conventional size, the adhesive area with the glass window 4 becomes smaller and the airtightness deteriorates.

This invention was made to solve the above problems, and is a miniaturized device that can maintain the airtightness of the optical semiconductor device itself and maintain the optical coupling characteristics of the optical coupling system. The purpose is to obtain an optical coupling system using an optical semiconductor device.

[Means to solve the problem]

In the optical coupling system using the optical semiconductor device according to the present invention, the cross-sectional shape of the window opening forming portion of the cap of the optical semiconductor device is tapered so that the opening becomes larger toward the top, and the lens is arranged in the opening. This is what I did.

[Effect]

In the optical coupling system using the optical semiconductor device in this invention,
Even when the optical semiconductor device is downsized, a sufficient adhesive area with the glass window can be secured and airtightness can be maintained. Further, even when an optical coupling system is constructed, a sufficient movable area of the lens is ensured, and the optical coupling characteristics do not deteriorate.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an outline drawing showing a small semiconductor laser diode used in an optical coupling system using an optical semiconductor device according to an embodiment of the present invention, and FIG. 1 is a sectional view showing an optical coupling system according to an embodiment, and in the figure, 1 is a laser diode chip, 2 is a monitor photodiode chip, and 3 is a support stand for the optical coupling system that hermetically seals the above 1.2. 3b is a tapered window opening that becomes larger toward the top; 4 is a glass window; 5 is a stem supporting 1 to 4; 6 is an electrode lead; 7 is a condensing lens; 8 is an optical fiber, 9 is a body that supports the above-mentioned 7.8 and is welded and fixed to the cap 3, 10 is a screw that determines the position of the condensing lens, l
la is the light emitted from the laser diode 1, and llb is the light that passes through the condensing lens 7, enters the optical fiber 8, and propagates.

Although the basic configuration and adjustment method of the optical coupling system are exactly the same as before, the cross-sectional shape of the window opening forming portion 3b of the cap 3 is
By forming a tapered shape with a larger aperture toward the top, even if the optical semiconductor device is designed to be compact, 1) the adjustment movable area of the light-condensing lens 7 can be secured in the same way as in the past; binding properties can be obtained.

2) The adhesion area between the glass window 4 and the cap 3 can be secured at the same level as before, and the same airtightness as before can be obtained.

This brings about this effect.

In the above embodiment, the cap window opening 3b has a tapered shape, but as shown in another embodiment of the present invention shown in FIG. Alternatively, as shown in still another embodiment of the present invention shown in FIG.
It may be tabular.

Further, in the above embodiment, a case was explained in which a semiconductor laser diode was used as the optical semiconductor device, but other optical semiconductor devices using a semiconductor light emitting diode or a semiconductor light receiving element may be used as the optical semiconductor device. The same effects as in the embodiment are achieved.

〔Effect of the invention〕

As described above, according to the present invention, in an optical coupling system using an optical semiconductor device, the window opening of the cap is formed into a tapered or stepped shape in which the opening becomes larger toward the top.
Even if the device is made smaller, the optical coupling characteristics are the same as the conventional type.
In addition, it has the effect of providing airtightness.

[Brief explanation of drawings]

FIG. 1 is an outline diagram of an optical semiconductor device used in an embodiment of the present invention, FIG. 2 is a sectional view showing an optical coupling system using the optical semiconductor device according to an embodiment of the present invention, and FIGS.
The figure is an outline diagram of an optical semiconductor device used in other embodiments and still other embodiments of the present invention, Figure 5 is an outline diagram of a conventional optical semiconductor device, and Figure 6 is an outline diagram of an optical semiconductor device using a conventional optical semiconductor device. FIG. 3 is a cross-sectional view showing an example of a coupling system. In the figure, 1 is a laser diode chip, 2 is a monitor photodiode chip, 3 is a cap, 3b is a window opening forming part, 4 is a glass window, 5 is a stem, 6 is a lead, 7 is a condensing lens, and 8 is a light beam. 9 is a body, 10 is a screw, lla is an output light, and 11b is light propagating through the fiber. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) An optical semiconductor device consisting of an optical semiconductor element, a stem that supports the optical semiconductor element and leads the electrodes of the element to the outside, and a cap that is welded to the stem and hermetically seals the optical semiconductor element. In the optical coupling system using the optical semiconductor device, the cross-sectional shape of the window opening forming portion of the cap of the optical semiconductor device is tapered or stepped, forming a larger opening toward the top, and the light from the optical semiconductor device is condensed. An optical coupling system using an optical semiconductor device, characterized in that a lens is disposed in an aperture formed by a window aperture forming portion of the cap.