JP2003167160A - Method for correcting optical axis of optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for correcting optical axis of an optical module, a method that can suppress increase in optical loss of an optical module which is manufactured by welding after optical axes are adjusted between optical components. <P>SOLUTION: With the tapered face 14b of a first optical component 11 brought into contact with the contact face 15b of a second optical component 15, and with the optical axes of these components 11, 15 aligned, the parts in contact are fixedly welded in this method for correcting optical axes of an optical module. While optical loss is monitored between the optical components 11, 15, an external force is successively actuated on a plurality of arbitrary places around the parts in contact, and then the place showing the minimum optical loss is irradiated with a laser beam. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting an optical axis of an optical module.

[0002]

2. Description of the Related Art As an optical module, for example, an optical module including at least an optical fiber, a lens and an optical filter, an optical module 1 having a structure shown in FIG. 4 is known. The optical module 1 includes a sleeve 2 and a holder 5
Is equipped with. The sleeve 2 holds the ferrule 3 to which the optical fibers 3a and 3b made of single mode fiber are attached. The holder 5 holds the optical filter 6 and the lens holder 8 holding the lens 8 a via the spacer 7.

In manufacturing the optical module 1, the sleeve 2 and the holder 5 are brought into contact with each other, and the light incident from the optical fiber 3a is reflected by the optical filter 6 and is incident on the optical fiber 3b while being emitted from the optical fiber 3b. Optimal position adjustment of the optical axes of the sleeve 2 and the holder 5 is performed so that the light loss due to light is minimized. Then, at this optimum centering position, the sleeve 2
The abutting portions of the holder 5 and the holder 5 are welded at equal intervals, for example, at 12 to 15 locations along the circumferential direction with a YAG laser.

In this welding, for example, first, three points that are equidistant from each other along the circumferential direction are welded at the same time, and then the positions are shifted in the circumferential direction, and further three points that are equidistant are welded at the same time. Then, while the position is shifted, the abutting portions of the sleeve 2 and the holder 5 are welded at 12 to 15 locations at equal intervals along the circumferential direction by welding at the three points along the circumferential direction two more times or three times. The optical module 1 is manufactured.

[0005]

By the way, in manufacturing an optical module having a sleeve and a holder, if the sleeve and the holder are fixed by welding with a YAG laser, the deviation of the irradiation position of the laser, the variation of the output, and the state of the welded portion may be prevented. Due to the difference and the like, shrinkage due to laser irradiation differs depending on the welding position. Therefore, in the manufactured optical module, the positions of the sleeve and the holder are tilted from the optimum alignment position.
As a result, in the optical module, the optical axis is deviated between the sleeve and the holder, and the optical loss between the optical fiber 3a and the optical fiber 3b is increased.

The present invention has been made in view of the above points, and an optical axis of an optical module capable of suppressing an increase in optical loss of an optical module manufactured by welding after adjusting an optical axis between optical components. The purpose is to provide a correction method.

[0007]

In order to achieve the above object in the present invention, a first optical component having a curved surface is provided with a second optical component having an abutting surface, and the abutting surface is provided with the curved surface. A method for correcting an optical axis of an optical module in which the abutting portion is fixed by welding in a state where the optical axes of the both optical components are adjusted,
While monitoring the light loss between the both optical components, an external force is sequentially applied to arbitrary plural places around the contact portion to irradiate the place where the light loss is minimum with laser light.

Preferably, the first optical component is a collimator in which a lens holder holding a lens is attached to a holding member holding a ferrule to which an optical fiber is attached, and the curved surface is formed in the lens holder. The configuration is Further preferably, the second optical component is a filter holder that holds an optical filter.

More preferably, the first optical component is a holder that holds an optical filter and a lens holder holding a lens via a spacer. Preferably, the second optical component is a holding member that holds a ferrule to which an optical fiber is attached.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an optical axis correcting method for an optical module according to the present invention will be described in detail below with reference to FIGS. As shown in FIG. 1, the optical module 10 includes a collimator 11 that is a first optical component and a filter holder 15 that is a second optical component.

The collimator 11 is, as shown in FIG.
A lens holder 14 is attached to the sleeve 12. The sleeve 12 is a ferrule 13 to which optical fibers 13a and 13b made of a single mode fiber are attached.
Holding The lens holder 14 is a cylindrical member that holds the lens 14a, and has a tapered surface 14b formed on the filter holder 15 side.

The filter holder 15 is an optical filter 15
As shown in FIG. 1, a cylindrical member holding a has an abutting surface 15b formed of a curved surface that abuts the tapered surface 14b. The optical module 10 includes an optical fiber 13
The light (wavelength λ1) incident from a is totally reflected by the optical filter 15a and emitted to the optical fiber 13b, and the light (wavelength λ2) incident on the filter holder 15 from the left is transmitted to the optical fiber 1
It has a multiplexing function of emitting to 3b. In addition, the optical module 10 receives light (wavelength λ
1 and λ2) has a demultiplexing function of totally reflecting the light of wavelength λ1 by the optical filter 15a and emitting it to the optical fiber 13a, transmitting the light of wavelength λ2 and emitting it to the left of the filter holder 15. There is.

The optical module 10 configured as described above
Is manufactured as follows. First, the sleeve 12
The lens holder 14 is fitted to the end of the collimator 11 and welded and fixed with a YAG laser to assemble the collimator 11. Next, the contact surface 15b is brought into contact with the tapered surface 14b so that the filter holder 1
5 is attached to the collimator 11. At this time, while monitoring the light that is incident from the optical fiber 13a, is totally reflected by the optical filter 15a and is emitted to the optical fiber 13b, while slightly moving the contact surface 15b along the tapered surface 14b,
The optical axes of the filter holder 15 and the collimator 11 are adjusted. With this optical axis adjusted, the contact portion where the contact surface 15b is in contact with the tapered surface 14b is welded and fixed by a YAG laser.

At the time of this welding, three YAG laser heads are arranged at 120 ° intervals on the outer circumference of the collimator 11,
The abutting surface 15b is welded to the tapered surface 14b at three locations along the circumferential direction of the abutting portion at equal intervals from three directions at the same time. As a result, the impacts caused by the welding become even, so that the displacement of the contact portion due to the impacts can be minimized. Then, while moving the irradiation position along the circumferential direction of the contact portion, the contact portion 15b is contacted with the tapered surface 14b by irradiating the YAG laser light 2 to 3 times, and the contact portion 6 is contacted with the contact surface 15b. The optical module 10 is manufactured by welding at 9 points.

The optical module 1 manufactured in this way
0 monitors the optical loss between the optical fibers 13a and 13b in the same manner as described above, and the optical axis correction is performed based on the optical axis correction method described below for the optical loss of a predetermined value or more. . First, the optical fiber 13a and the optical fiber 13
While monitoring the optical loss between the contact surface 15b and the contact surface b, external force (see the arrow in FIG. 2) is applied to arbitrary plural points around the contact portion where the contact surface 15b contacts the tapered surface 14b, for example, by using a metal rod. Let it work sequentially. In this way, the external force is sequentially applied to any desired plurality of locations, and the location where the optical loss to be monitored is minimized is searched for.

When the location where the light loss is minimized is found, the external force applied by the metal rod is released, and YAG laser light having an energy corresponding to the increase in the light loss value before and after welding and fixing is applied. . Regarding the energy of the YAG laser light to be irradiated, an experiment was performed in which the energy value of the laser light to be irradiated was changed variously depending on the increase in the optical loss value before and after welding and fixing, and the optimum irradiation energy value for correcting the angle deviation was obtained. . The results are shown in Table 1.

[0017]

[Table 1]

This optical axis correction is repeated several times until the increment of the optical loss value becomes about ± 0.01 dB compared with the time when the optical axes of the filter holder 15 and the collimator 11 are adjusted before welding and fixing. To do. As a result, in this embodiment, regarding the optical loss between the optical fiber 13a and the optical fiber 13b,
When the optical axes of the filter holder 15 and the collimator 11 are adjusted before welding and fixing, the filter holder 15 and the collimator 1
Table 2 shows the optical loss in each of 1 and 2 after being fixed by welding with a YAG laser and after the optical axis was corrected.

[0019]

[Table 2]

Therefore, according to the method of the present invention, the deviation of the optical axis caused by the welding in the optical module manufactured by welding after the optical axis adjustment between the optical parts is adjusted to the state before the optical axis adjustment before welding. Can be recovered. Here, the method of the present invention is not limited to the optical module 10 of the above-described embodiment, but the optical module 20 shown in FIG.
Can also be applied to.

The optical module 20, as shown in FIG.
It comprises a holder 21 which is a first optical component and a sleeve 25 which is a second optical component. As shown in FIG. 3, the holder 21 is a cylindrical member, and includes an optical filter 22 and a lens holder 24 holding a lens 24 a and a spacer 23.
And a tapered surface 21a is formed on the sleeve 25 side.

The sleeve 25, as shown in FIG. 3, is an optical fiber 26a, 26 made of a single mode fiber.
Hold the ferrule 26 with the b
An abutting surface 25a that is a curved surface that abuts a is formed. Furthermore, the method of the present invention is the optical module 1 described above.
In addition to 0 and 20, a second optical component having a contact surface is brought into contact with the first optical component having a curved surface, and the contact surface is brought into contact with the curved surface to adjust the optical axes of the both optical components. It goes without saying that the optical module can be applied to various optical modules as long as it is an optical module in which the contact portion is welded and fixed in this state.

[0023]

According to the present invention, the optical axis correction of the optical module capable of suppressing the increase of the optical loss in the optical module manufactured by welding after adjusting the optical axes of the optical components. A method can be provided.

[Brief description of drawings]

FIG. 1 is a sectional front view of an optical module to which an optical axis correcting method of the present invention is applied.

FIG. 2 is an enlarged view of part A in FIG.

FIG. 3 is a sectional front view of another optical module to which the optical axis correcting method of the present invention is applied.

FIG. 4 is a sectional front view of an optical module for explaining a conventional optical axis correcting method.

[Explanation of symbols]

10 Optical Module 11 Collimator (First Optical Component) 12 Sleeve 13 Ferrules 13a, 13b Optical Fiber 14 Lens Holder 14a Lens 14b Tapered Surface 15 Filter Holder (Second Optical Component) 15a Optical Filter 15b Contact Surface 20 Optical Module 21 Holder (first optical component) 21a Tapered surface 22 Optical filter 23 Spacer 24 Lens holder 24a Lens 25 Sleeve (second optical component) 25a Contact surfaces 26a, 26b Optical fiber 26 Ferrule

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Nobuaki Sato             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. (72) Inventor Hiroshi Matsuura             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. F-term (reference) 2H036 MA07 NA03 NA12

Claims (5)

[Claims] 1. A first optical component having a curved surface, a second optical component having a contact surface is brought into contact with the curved surface to adjust the optical axes of the both optical components. A method for correcting an optical axis of an optical module in which a contact portion is welded and fixed in a state, wherein an external force is sequentially applied to an arbitrary plurality of locations around the contact portion while monitoring optical loss between the optical components, A method of correcting an optical axis of an optical module, which comprises irradiating a laser beam to a portion where the optical loss is minimum. 2. The first optical component is a collimator in which a lens holder holding a lens is attached to a holding member holding a ferrule to which an optical fiber is attached, and the curved surface is formed in the lens holder. A method for correcting an optical axis of an optical module according to claim 1. 3. The optical axis correcting method for an optical module according to claim 1, wherein the second optical component is a filter holder that holds an optical filter. 4. The optical axis correction method for an optical module according to claim 1, wherein the first optical component is a holder that holds an optical filter and a lens holder that holds a lens via a spacer. 5. The second optical component is a holding member that holds a ferrule to which an optical fiber is attached.
Optical module optical axis correction method.