JPH0499081A - Connecting structure between semiconductor laser package and package for modulator - Google Patents

Abstract

PURPOSE:To make the title connecting structure perfectly airtight and, at the same time, to efficiently couple the structure with the polarizing direction of a semiconductor laser module by connecting a package for mounting a modulator to a semiconductor laser package by laser-welding through an isolator. CONSTITUTION:Glass windows 22 and 23 are respectively installed to the front and rear faces of a package 2 for modulator incorporating an LN modulator 23. Then the package 2 is inserted into a flange 4 provided with a hole 41 into which the front face of the package 2 can be inserted. A glass window 11 through which laser light is outputted is provided to the front face of a semiconductor package 1. The window in the front face of the package 1 and the front face of an isolator holder 3 housing an isolator 31 are faced to each other and laser-welded. After the rear face of the isolator 31 is positioned to the surface of the flange 4 where the package 2 is not inserted, the rear face of the isolator 31 is laser-welded to the flange 4 by the section encircled by the dotted line.

Description

[Detailed Description of the Invention] [Summary] Regarding the connection between the modulator package and the semiconductor laser package, the purpose is to complete the airtight mechanism and to enable efficient coupling with the polarization direction of the semiconductor radar module. A package equipped with a modulator is connected to a semiconductor laser package by laser welding via a flange and an isolator.

[Industrial application field]

DISCLOSURE OF THE INVENTION As optical communication systems become faster and longer distances, broadening of the wavelength spectrum (chirping) during high-speed modulation of semiconductor lasers has become a major problem.

Therefore, a technique has been considered in which the semiconductor laser continues to emit light and is modulated by external modulation.

As means for performing external modulation, there is a waveguide type modulator (hereinafter abbreviated as LN modulator) using a lithium-diffused niobium oxide waveguide.

The LN modulator and the package housing the semiconductor laser are each hermetically sealed, and there is a demand for these packages to maintain airtightness, be easily connectable, and to be miniaturized.

[Conventional technology]

FIG. 3 shows the configuration of a conventional semiconductor laser package l.

A lens holder having a lens 12 for converting laser light into parallel light is laser welded to a substrate on which a semiconductor laser 13 is mounted.

Then, it is hermetically sealed by the window 11.

Light from window 11 is input to isolator 31.

The output of the isolator 31 is input to a stainless steel holder 32 that houses a lens and an optical fiber.

The stainless steel holder 32 is connected to a hole provided on the front surface of the semiconductor laser package by laser welding.

Further, an optical connector 34 is provided at the tip of the optical fiber from the stainless steel holder 32.

FIG. 4 shows the configuration of a conventional modulator package.

A metallized portion is provided between the optical fibers whose one end is connected to the optical connector 35, and the metallized portion is connected to the stainless steel holder 33 with solder.

The stainless steel holder 33 is fixed to the modulator package 2 with silver solder, gold tin, or the like.

After the connection, a ruby bead 37 is provided at the tip of the optical fiber, and the ruby bead 37, the end of the LN modulator 24, and the gutter 38 provided at the upper end of the LN modulator 24 are connected with an adhesive.

FIG. 5 shows the conventional overall configuration.

By connecting the optical connector 34 of the semiconductor laser package 1 shown in FIG. 3 and the optical connector 35 provided at once in the modulator package 2 shown in FIG. I was connecting package 2.

[Problem to be solved by the invention]

In the conventional configuration, the connection between the LN modulator 24 and the optical fiber is made using ruby beads using an adhesive, which poses a problem of airtight reliability against temperature fluctuations and aging.

Furthermore, since the semiconductor laser package 1 and the modulator package 2 are connected using an optical fiber, there is a problem of an increase in size.

Furthermore, since the optical fibers are connected by optical connectors, there have been problems such as the inability to precisely adjust the position of the plane of polarization.

Therefore, in the present invention, in the modulator package 2,
The purpose is to optically couple the LN modulator 24 and the semiconductor laser 13 without using an optical fiber so that the coupling efficiency and polarization plane do not change due to changes in temperature or aging.

[Means to solve the problem]

The basic configuration of the present invention is shown in FIG.

In the present invention, glass windows 22 and 23 are provided on the front and rear surfaces of the modulator package 2 containing the LN modulator 24.

Furthermore, the front surface of this modulator package 2 is inserted into the flange 4 having a hole 41 into which it can be fitted.

A glass window 11 for outputting laser light is provided on the front surface of the semiconductor laser package 1.

The front window 11 of the semiconductor laser package 1 and the front surface of the isolator holder 3 containing the isolator 31 are faced to each other and laser welded.

After alignment adjustment is performed between the rear surface of the isolator 31 and the surface of the flange 4 where the modulator package 2 is not fitted, a laser welded structure is formed at the dotted line portion.

[Effect]

In the present invention, glass windows 22 and 23 for inputting and outputting laser light are provided on the front and rear surfaces of the modulator package 2 housing the LN modulator 24, and the modulation package 2 is inserted into the flange 4. By fixing it, it is possible to connect to the isolator 31 without using an optical fiber.

Furthermore, since laser welding is performed after adjusting the flange 4 to an arbitrary position, it is possible to improve coupling efficiency and reduce loss due to the plane of polarization.

Furthermore, by providing a window 11 on the semiconductor laser package 1 side, laser welding can be performed with the isolator holder 3, and the structure as a whole does not use optical fibers, which simplifies the structure and reduces the size. can be done.

〔Example〕

Embodiments of the present invention will be described below using the drawings.

Figures 2a and 2b show an embodiment of the invention.

FIG. 2a is a top view of the embodiment of the present invention, and FIG. 2A is a side sectional view of the embodiment of the present invention.

The semiconductor laser package 1 has a semiconductor laser 13 inside.
A lens 12 is provided to convert the laser beam of the semiconductor laser into parallel light.

A hole is made in the front side of the semiconductor laser package 1, and a window 11 made of sapphire glass is covered with silver solder or
It is fixed with gold and tin so that the inside is hermetically sealed.

The isolator 3 has a hole in which the isolator 31 is provided, and the hole is oblique to the incident optical axis.

The modulator package 2 has windows 21 and 23 with holes formed on its front and rear surfaces and made of sapphire glass.
is fixed with silver solder or gold tin to airtightly seal the inside.

At the center of the lower surface of the modulator package 2 is a pedestal 28 made of 5US16 having the same temperature coefficient as the LN modulator.
An LN modulator 24 is provided on the pedestal 28, and an LN modulator 24 is provided on the front side to control the light emission mode of the semiconductor laser umbrella.
A lens 25 for converting into the propagation mode of the N modulator is provided, and a lens 26 for coupling with the transmission path is provided on the rear side.

The lenses 25 and 26 are housed in a metal holder and fixed to the modulator package 2 by laser welding.

A lid 27 is placed on the top surface of the modulator package 2.
7 is hermetically sealed and fixed to the upper part of the modulator package 2 by laser welding or parallel seam welding.

A grounding foil 29 is provided on the side surface of the modulator package 2.

The modulator package 2 is fitted into the hole 41 of the flange 4 .

This fitting part is connected by laser welding.

The isolator holder 3 and the semiconductor laser package 1 are welded together using a laser.

The modulator package 2 of the flange 4 is inserted and fitted, and the inner surface of the isolator 4 is welded with a laser after adjusting the optical coupling position and the polarization coupling position.

〔Effect of the invention〕

The present invention has a configuration in which the modulator package is connected to the semiconductor laser package through a flange and an isolator by laser welding, so that the connection between the LN modulator and the semiconductor laser is achieved through space without using adhesive. As a result, reliability against temperature fluctuations and aging changes is improved.

Furthermore, since the configuration does not use optical fibers, it is possible to downsize the device.

Furthermore, since the connection is made using the flange 4, the position of the plane of polarization, etc. can be adjusted with good accuracy.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the principle configuration of the present invention, Fig. 2 is a diagram showing an embodiment of the invention, Fig. 3 is a diagram showing a conventional semiconductor laser package, and Fig. 4 is a diagram showing a conventional modulator package. It is a diagram. In the figure, 1 is a semiconductor laser package, 2 is a modulator package, 22, 23, and 11 are windows, and 3 is an isolator procedure amendment (method).Indication of the case 1990 Patent Application No. 072394 No. 10 of the title specification of the invention In the 11th and 12th lines of the page, "I will use the diagram to show." should be changed to "Diagram to show." Figure 5 is a diagram showing the conventional configuration. Amended to J. Relationship to the case Patent applicant's address Kanagawa Prefecture Kamiodanaka, Nakahara-ku, Yozaki-shi Name (522) Fujitsu Ltd. Representative: Yoshi Sekizawa 4, Agent Postal code: 211 Address 5 @ 1015 Kamiodanaka, Nakahara-ku, Yozaki-shi, Kanagawa Prefecture

Claims (1)

[Claims] A semiconductor laser package in which a semiconductor laser is hermetically sealed (
1) and a modulator package (2) in which a modulator constituted by an optical waveguide is hermetically sealed, the semiconductor laser package (1) has a glass plate on the front surface for outputting semiconductor laser light. A window (11) is provided, and an isolator holder (3) containing an isolator is brought into contact with a position facing the window (11) on the front surface and laser welded, and the input/output side of the modulator package (2) is In addition to providing windows (22, 23) for inputting and outputting modulated light and modulated light, a flange (4) having a hole (41) into which the modulator package (2) can be fitted is provided with windows (22, 23) for inputting and outputting modulated light. The modulator package (2) is fitted and the fitted part is laser welded, and the modulator package (4) connected to the flange (4) is fitted.
2) is laser welded to the optical output side of the isolator holder (3). A connection structure for a semiconductor laser package and a modulator package.