JPH0453912A - Optical axis aligning method for photodetecting module - Google Patents

Abstract

PURPOSE:To economically attain the optical axis alignment by moving a photodetector vertically, to the left and the right, and forward and backward, and detecting a position in which an image of the photodcetecting surface formed on a focal plane is formed in the center of a target line, and also, the most distinct image is formed. CONSTITUTION:In a glass block 6, one face is used as a focal plane, and on this focal plane, a target line is carved. The glass block 6 is inserted into an insertion hole of a holder 2, and the focal plane of the glass block 6 is fixed to a focal plane position 5. Subsequently, the focal plane of the glass block 6 is photographed by a TV camera 7, and while looking at an image displayed on a monitor TV 8, a photodetector 1 is moved vertically, to the left and the right, and forward and backward so that the photodetecting surface 4 is positioned in the center of a target line, and also, a distinct image is formed, and positioning is executed. When positioning of the photodetector 1 is finished, a fixing part 9 is fixed by soldering, etc. In such a way, even a worker who does not have especially high skill can execute the work by the minimum manhour, and the alignment can be executed economically.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for adjusting the optical axis of a light receiving module.

[Conventional technology]

As shown in the explanatory diagram of FIG. 3, the conventional method for adjusting the optical axis of a light-receiving module is to fix a light-receiving element 11 to one end of a holder 12 and use an optical connector to accommodate the end of an optical fiber 14 through a lens 13. The optical fiber 15 is optically connected to the ferrule 15, the light beam emitted from the optical fiber 14 is received by the light receiving surface 16, and the amount of received light is maximized while monitoring the photocurrent corresponding to the amount of received light with an ammeter 17. Thus, the light receiving element 11 is moved vertically, horizontally, and front and back at one end of the holder 12, and after reaching a desired value, the light receiving element 11 is fixed to one end of the holder 12 by soldering or the like.

[Problem to be solved by the invention]

The above-described conventional method for adjusting the optical axis of a light-receiving module is to receive the light emitted from the optical fiber 14 on the light-receiving surface 16 without directly monitoring the light-receiving element, and to measure the photocurrent corresponding to the amount of received light using the ammeter 17. While monitoring, the amount of light received is adjusted by moving the light receiving element 11 up and down, left and right, and forward and backward at one end of the holter 12, so that the sensitive area of the light receiving element is wide, but the dynamic characteristics The good area is limited to a relatively narrow area near the center, and there is a problem in that it requires a large amount of man-hours to adjust the position in order to position the photodetector at the center of the area of maximum photocurrent. . or,
If the photodetector and holder are fixed in a state where the center positioning accuracy of the maximum photocurrent area is insufficient, dynamic characteristics will deteriorate if the optical axis shifts due to changes over time, so this optical axis adjustment is necessary. Another problem is that workers are required to have high skills.

An object of the present invention is to provide an economical optical axis adjustment method for a light-receiving module that allows even workers without particularly high skills to perform the work with a minimum number of man-hours by performing center positioning while directly monitoring the light-receiving element. There is a particular thing.

[Means to solve the problem]

The method for adjusting the optical axis of a light receiving module according to the present invention includes holding an optical connector ferrule that accommodates an end of an optical fiber in a removably connected state to one end of a holder, providing a lens inside the holder, and connecting the optical fiber through the lens. In the method for adjusting the optical axis of a light receiving module, in which a light receiving element for receiving an optical signal from the optical fiber is fixed to the other end of the holder, one surface of the holder is set as a focusing surface on the insertion part of the optical connector ferrule. A glass block with a target line engraved on the focus surface is inserted, an image of the light-receiving surface of the light-receiving element is formed on the focus surface by the lens, and the focus surface is moved by moving the light-receiving element up and down, left and right, and front and back. The light-receiving element is configured to detect a position where the image of the light-receiving surface formed at the center of the target line and forming the clearest image, and to fix the light-receiving element at the detected position.

The optical axis adjustment method of the light receiving module of the present invention uses a television camera to detect the position where the image of the light receiving surface formed on the focusing surface is focused on the center of the target line and the clearest image is formed. In the method for adjusting the optical axis of a light-receiving module of the present invention, a light source may be provided near the lens of the television camera, and the light-receiving surface may be illuminated through the lens in the holder.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view of one embodiment of the present invention.

The light-receiving element 1 is inserted into one end of the holder 2, and the image of the light-receiving surface 4 inside the light-receiving element 1 is focused through the lens 3 at a focal plane position 5.
It is designed to form an image. The glass block 6 is inserted into an insertion hole for inserting an optical connector ferrule when the holder 2 is in use, and is used for optical axis adjustment.
One surface is set as a focus surface, a target line is carved on this focus surface, and this focus surface is fixed at focus surface position 5. A television camera (hereinafter referred to as TV camera) 7 photographs the focused surface of glass block 6, and displays an image on a monitor television receiver (hereinafter referred to as monitor TV) 8. The fixing part 9 is a part that is fixed by soldering or the like after the positioning of the light receiving element 1 is completed to the gap between the light receiving element 1 and the holder 2.

FIG. 2 is a diagram showing an image displayed on a monitor TV.

The circle in the center shows the image of the light-receiving surface 4, and the outer circle and crosshairs indicate the optical axis carved on the focus surface of the glass block 6.
Indicates the target line to display.

Next, the optical axis adjustment method will be explained.

The glass block 6 is inserted into the insertion hole of the holder 2, and the focus surface of the glass block 6 is fixed at the focus surface position 5. Next, take a picture of the focused surface of the glass block 6 with the TV camera 7, and while watching the image displayed on the monitor TV 8, make sure that the light receiving surface 4 is located in the center of the target line and that a clear image is formed.
The light receiving element 1 is moved up and down, left and right, and front and back to determine its position. When the positioning of the light receiving element 1 is completed, the fixing part 9 is fixed by soldering or the like.

When photographing an image of the light-receiving surface 4 in the light-receiving element 1, the light-receiving surface 4
However, since the holder 2 is usually made of a light-shielding material, it is necessary to introduce light from the outside.

For this reason, for example, it is conceivable to make a hole in a part of the body of the holder 2 to let in external light, but this is not a good idea as it becomes necessary to close the hole in the end. Therefore, by providing a light source 9 near the lens of the TV camera 7 and illuminating the light receiving surface 4 through the lens 3 inside the holder 2, the present invention can be carried out without making any changes to the holder 2. It becomes possible.

〔Effect of the invention〕

As explained above, in the present invention, a glass block with one surface as a focusing surface and a target line carved on the focusing surface is inserted into the insertion part of the optical connector ferrule of the holder, and the lens in the holder is used to detect the light receiving element. The image of the light-receiving surface is focused on the focus surface, and while the light-receiving element is moved up and down, left and right, and front and back, the image of the light-receiving surface that is focused on the focus surface is focused on the center of the target line and forms the clearest image. By detecting the position,
This has the effect that even workers who do not have particularly high skills can perform the work with a minimum number of man-hours, and adjustment work can be carried out economically.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention, FIG. 2 is a diagram showing an image displayed on a TV monitor, and FIG. 3 is an explanatory diagram of a conventional method for adjusting the optical axis of a light receiving module. 1... Light receiving element, 2... Holder, 3...
・・・・Lens, 4・・・・−・Light receiving surface, 5・・・・・・
・Focus surface position, 6...Glass block, 7・
...Television camera (TV right camera, 8...
...Monitor television receiver (monitor TV), 9
...Fixed part, 10...Light source. Agent Patent Attorney Susumu Uchihara 1 yen

Claims (1)

[Claims] 1. An optical connector ferrule that accommodates the end of an optical fiber is held in a removably connected state at one end of a holder, and a lens is provided inside the holder, and the optical fiber is inserted through the lens. In the method for adjusting the optical axis of a light receiving module, in which a light receiving element for receiving an optical signal from the holder is fixed to the other end of the holder, one surface of the insertion part of the optical connector ferrule of the holder is set as a focusing surface, and a target is set on this focusing surface. A glass block carved with lines was inserted, an image of the light-receiving surface of the light-receiving element was formed on the focus surface by the lens, and the image was formed on the focus surface by moving the light-receiving element up and down, left and right, and front and back. A method for adjusting an optical axis of a light receiving module, comprising detecting a position where an image of the light receiving surface forms the center of the target line and forming the clearest image, and fixing the light receiving element at the detected position. . 2. A television camera is used to detect the position where the image of the light-receiving surface formed on the focus surface is focused on the center of the target line and forms the clearest image. 1. The optical axis adjustment method of the light receiving module according to 1. 3. The optical axis adjustment method for a light receiving module according to claim 1, wherein a light source is provided near the lens of the television camera, and the light receiving surface is illuminated through the lens in the holder.