CN1235014C - Semiconductor laser device mounting aligning and correcting method - Google Patents

Abstract

A method for installing and aligning a semiconductor laser, comprising the steps of: fixing a TO tube shell sintered with a laser tube core on a support, and the bottom plane of the TO tube shell is close to the bracket to ensure that the direction of the central axis of the TO tube shell is in the y direction ; Use a collimated visible light laser to illuminate the crystal natural cleavage surface of the semiconductor laser chip (i.e. the exit cavity surface of the laser) in the direction of θ angle with the y direction; at a distance of D from the exit cavity surface of the laser Fix a ruler so that the light reflected by the cavity surface of the semiconductor laser will show a light spot on the ruler; when the laser cavity surface is perpendicular to the central axis of the tube shell, the light spot on the ruler and the reflected light are calculated by the formula The distance between the points; by measuring the distance E, the angular deviation a between the laser light emitting direction and the central axis of the TO shell can be measured.

Description

Method for Alignment and Calibration of Semiconductor Laser Installation

technical field

The invention belongs to the field of semiconductor technology, in particular to a method for mounting, aligning and calibrating a semiconductor laser in the field of optoelectronic technology.

Background technique

Since the 1970s, due to important breakthroughs in optical fiber technology and semiconductor lasers, optical information technology represented by optical fiber communication, optical fiber sensing, optical information storage, optical information processing and display has flourished. This in turn promotes the wider application of semiconductor lasers. In most applications of semiconductor lasers, the coupling of semiconductor lasers and optical fibers is involved. How to improve the coupling efficiency of lasers and optical fibers has become a key technology of semiconductor lasers. The coupling packaging methods of semiconductor lasers and optical fibers mainly include coaxial packaging, dual in-line packaging, butterfly packaging, and packaging with radio frequency interfaces. Coaxial packaging has the advantages of small parasitic parameters, simple process, and low cost, and is widely used in LED, LD, and light-receiving device and component packaging. The entire coaxial structure is composed of TO tube base, tube cap, inner sleeve, outer sleeve and internal optical system, and the upper and lower parts of the structure have consistent concentricity. The installation of the semiconductor laser on the TO tube base is very important to the coupling efficiency and yield of the coaxial package. Generally speaking, it is required that the light-emitting axis of the laser coincides completely with the central axis of the TO socket. see picture 1. Alignment in X, Y, and Z directions can be achieved by aligning marks under a high-power microscope, while alignment in angle is difficult to achieve with a microscope. Because the angle deviation is 1-2 degrees, the coupling efficiency will change greatly, and even the light cannot be coupled out. The invention detects the deviation of the light-emitting direction through the reflected light of the cavity surface of the laser. The method can be used in the real-time installation of the semiconductor laser, improves the alignment precision, and improves the coupling efficiency and yield.

Contents of the invention

The object of the present invention is to provide a semiconductor laser installation alignment and calibration method, which can be used in the real-time installation of semiconductor lasers to improve alignment accuracy, coupling efficiency and yield. When improving the accuracy of chip installation, the problem of quantitative measurement and correction of the deviation between the light output direction of the semiconductor laser and the central axis of the TO shell is especially solved.

A method for mounting and aligning a semiconductor laser of the present invention is characterized in that it comprises the following steps:

1) Fix the TO shell with the sintered laser die on the fixing bracket, and the bottom plane of the TO shell is close to the fixing bracket to ensure that the central axis direction of the TO shell is in the y direction;

2) Use a collimated visible light laser pointer to irradiate the light exit cavity surface of the crystal of the semiconductor laser chip in a direction that forms an angle θ with the y direction;

3) Fix a ruler at a distance D from the exit cavity surface of the laser, so that the light reflected from the exit cavity surface of the semiconductor laser will show a spot A2 on the ruler;

4) When the laser cavity surface is perpendicular to the central axis of the tube shell, the reference point A1 can be determined, and the determination of the reference point A1 includes:

41) Take a lens and fix it on the TO shell bracket;

42) The plane of the lens is parallel to the contact surface of the fixed bracket and the bottom surface of the TO tube, and the reflection surface and the laser cavity surface are on the same plane. The light point reflected by the mirror is A1 point. Note that this method is fixed The contact surface between the bracket and the bottom surface of the TO tube is the reference plane, so the contact surface should be smooth and in close contact with the bottom surface of the TO tube shell and the ordered reflector surface;

5) By measuring the distance E between A1 and A2, the angular deviation a between the laser light emitting direction and the central axis of the TO shell can be calculated;

From the position movement of the reflected light point in the z direction, the angular deviation of the laser die in the z direction can be judged; similarly, from the position movement of the reflected light point in the x direction, the angle deviation of the laser die in the x direction can also be judged. Angle deviation.

Wherein step 4) said to calculate the angular deviation a of the laser light emitting direction and the central axis of the TO shell by the formula; its formula is:

E=D{tg(θ+2a)-tgθ}

Where θ is the incident angle of the visible light laser, a is the deviation angle, and E is the distance between A1 and A2.

Description of drawings

In order to further illustrate the technical content of the present invention, below in conjunction with embodiment and accompanying drawing describe in detail as follows, wherein:

Fig. 1 is a schematic diagram of installation of the present invention;

Figure 2 is a schematic diagram of the TO shell fixing bracket;

Fig. 3 is a schematic diagram of a device for detecting angular alignment using a visible laser.

Detailed ways

Referring to Fig. 1, Fig. 2 and Fig. 3, a method for mounting and aligning a semiconductor laser of the present invention comprises the following steps:

1) Fix the TO shell 1 with the sintered laser die 2 on the fixing bracket 4, and the bottom plane of the TO shell 1 is close to the fixing bracket 4 to ensure that the central axis direction of the TO shell 1 is in the y direction;

2) Use a collimated visible light laser pointer 7 to irradiate the crystal natural cleavage surface of the semiconductor laser chip (ie, the light exit cavity surface 5 of the laser) in a direction that forms an angle θ with the y direction;

3) Fix a ruler 3 at a distance of D from the laser exit cavity surface 5, so that the light reflected by the semiconductor laser exit cavity surface 5 will show a light spot on the ruler 3;

4) When the surface of the laser light exit cavity is perpendicular to the central axis of the shell, the reflected light point is the reference point A1. When there is an angle a, the reflected light point is A2;

5) By measuring the distance E, the angular deviation a between the laser light emitting direction and the central axis of the TO shell can be measured;

The calculation formula is:

E=D{tg(θ+2a)-tgθ}

Where θ is the incident angle of the visible light laser, a is the deviation angle, and E is the distance between A1 and A2;

From the position movement of the reflected light point in the z direction, the angular deviation of the laser die in the z direction can be judged; similarly, from the position movement of the reflected light point in the x direction, the angle deviation of the laser die in the x direction can also be judged. Angle deviation.

A method for mounting and calibrating a semiconductor laser of the present invention comprises the following steps:

1) Take a lens and fix it on the TO shell bracket 4;

2) The plane of the lens is parallel to the contact surface of the fixed bracket 4 and the bottom surface of the TO tube, and the reflection surface and the light exit cavity surface of the laser are on the same plane. The light point reflected by the mirror is A1 point. Note that this method is based on The contact surface on the fixed bracket 4 and the bottom surface of the TO tube is the reference plane, so the contact surface should be smooth and in close contact with the bottom surface of the TO tube shell and the surface of the ordered reflector.

Calibration method of the present invention is to determine datum point A1: get a lens, be fixed on the TO shell support 4, the plane of eyeglass and TO shell support 4 and the contact surface of TO shell 1 bottom surface are parallel, and make reflective surface and The laser cavity surface is on a plane, and the light point reflected by the mirror is point A1. Note that this method uses the contact surface between the bracket and the bottom surface of the TO tube as the reference plane, so the contact surface should be smooth and consistent with the bottom surface of the TO tube shell. In close contact with the target mirror surface.

By adopting this method, the alignment accuracy when the laser is sintered on the TO tube shell 1 is greatly improved, especially the problem of low coupling efficiency of individual tubes in the subsequent coupling of the laser and the optical fiber is solved, and the yield rate is improved.

Example

Fix the TO tube on the bracket 4, as shown in Figure 2. Make the bottom surface of the TO tube case 1 close to the bracket 4, and ensure that the direction of the central axis of the TO tube case 1 is perpendicular to the reference plane. Make another support, as shown in Figure 3, fix the visible light laser pointer 7, the measuring scale 3 and the slide plate 6 used as the reference plane on the desktop. Note that the slide and the ruler should be parallel. The TO package fixing bracket 4 is placed on the slide plate 6, and the light beam of the laser pointer 7 forms a certain angle θ with the slide plate, such as 45 degrees. Turn on the power of the laser pointer 7, the emitted parallel light is parallel to the bottom surface and incident on the laser cavity surface on the TO tube shell (assuming that the cavity surface of the laser tube core is absolutely perpendicular to the central axis of the tube shell), and the reflected light is generated on the scale. a spot of light. The angle deviation of the tube core sintering in the horizontal direction can be judged by the position of the light spot; similarly, the angle deviation of the tube core sintering in the vertical direction can also be judged. The TO tube case fixing bracket 4 slides along the slide plate 6 to determine the sintering angle deviation of other tube cores mounted on the TO tube case fixing bracket 4 in turn.

Determination of reference point A1: use a flat mirror, fix it on the same plane as the light exit cavity surface of the tube core, so that the mirror surface is strictly parallel to the slide plate. At this time, the light spot position of the reflected light on the scale is the reference point A1.

Claims (2)

1. A method for mounting and aligning a semiconductor laser, characterized in that, comprising the steps of: 1) Fix the TO shell with the sintered laser die on the fixing bracket, and the bottom plane of the TO shell is close to the fixing bracket to ensure that the central axis direction of the TO shell is in the y direction; 2) Use a collimated visible light laser pointer to irradiate the light exit cavity surface of the crystal of the semiconductor laser chip in a direction that forms an angle θ with the y direction; 3) Fix a ruler at a distance D from the exit cavity surface of the laser, so that the light reflected from the exit cavity surface of the semiconductor laser will show a spot A2 on the ruler; 4) When the laser cavity surface is perpendicular to the central axis of the tube shell, the reference point A1 can be determined, and the determination of the reference point A1 includes: a) Take a lens and fix it on the TO shell bracket; b) The plane of the lens is parallel to the contact surface of the fixed bracket and the bottom surface of the TO tube, and the reflective surface and the laser cavity surface are on the same plane. The light point reflected by the reflector is A1 point. Note that this method is fixed The contact surface between the bracket and the bottom surface of the TO tube is the reference plane, so the contact surface should be smooth and in close contact with the bottom surface of the TO tube shell and the ordered reflector surface; 5) By measuring the distance E between A1 and A2, the angular deviation a between the laser light emitting direction and the central axis of the TO shell can be calculated; From the position movement of the reflected light point in the z direction, the angular deviation of the laser die in the z direction can be judged; similarly, from the position movement of the reflected light point in the x direction, the angle deviation of the laser die in the x direction can also be judged. Angle deviation. 2. The method for mounting and aligning a semiconductor laser according to claim 1, wherein said step 4) calculates the angular deviation a of the laser light-emitting direction and the central axis of the TO tube shell by a formula; its formula is : E=D{tg(θ+2a)-tgθ} Where θ is the incident angle of the visible light laser, a is the deviation angle, and E is the distance between A1 and A2.

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