JP2833350B2 - Device and method for connecting optical fiber and silica-based waveguide optical component - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection device and a connection method for connecting an optical fiber and a silica-based waveguide type optical component using a carbon dioxide laser beam.

[0002]

2. Description of the Related Art Silica-based waveguide optical components can be mass-produced to meet the needs of the optical communication era, and low-loss permanent connection can be achieved by fusion splicing with a silica-based optical fiber. 2. Description of the Related Art Passive elements such as a wavelength multiplexer / demultiplexer and an optical star coupler have been actively developed.

Generally, carbon dioxide laser light is used for fusion splicing between a silica-based waveguide optical component and a silica-based optical fiber. Carbon dioxide laser light (hereinafter, laser light) has a wavelength of 10.6 μm and is efficiently absorbed by a quartz-based material, so that it is optimal as a heat source for fusion splicing. In addition, the carbon dioxide laser light can be selectively melted by irradiating an arbitrary portion of the quartz-based material as a minute spot by condensing the laser beam with a lens.

At the stage of manufacturing a module using a silica-based waveguide optical component, the core 4 of the optical fiber 3 is attached to the end face of the waveguide optical component 2 fixed in a metal package 1 as shown in FIG. and butt to expose the cladding 5, the laser beam 7 condensed by the lens 6 from the upper side, by irradiating the connecting portion 8 in the arrow P ₁ direction and a core 9 of the core 4 and the waveguide type optical component 2 fusion In general, the clad 4 and the clad 10 of the waveguide-type optical component 2 are fusion-spliced together with the spliced connection. FIG. 3 is a view showing a state of fusion splicing of a waveguide type optical component and an optical fiber.

By the way, when the optical component 2 and the optical fiber 3 are fusion spliced, if the optical axes of the two components 2 and 3 do not coincide, the connection loss increases. This is very important.

On the other hand, single-mode optical fibers having a core diameter of 9 μm are frequently used for long-distance optical communication in the 1.3 μm and 1.5 μm wavelength bands, and a glass waveguide for multiplexing and demultiplexing signals in the optical fiber 3. As the mold optical component, one having a rectangular core of 8 μm × 8 μm is used. That is, unless the cores having an outer diameter of about 9 μm are accurately aligned and fusion-spliced, an excessive loss of optical power occurs at the joint,
Reflected return light and scattered light are increased, and transmission characteristics are significantly deteriorated.

Therefore, in order to prevent the characteristic deterioration due to the misalignment of the connecting portion, the optical axis of the waveguide type optical component 2 and the optical axis of the optical fiber 3 must be strictly aligned before fusion splicing. Required.

In general, for adjusting the optical axis, a waveguide type optical component 2 is used.
Alternatively, a method is used in which a laser beam for monitoring is incident on one of the optical fibers 3 and the laser beam is aligned so that the power of the laser beam is maximized when the laser beam is received on the other side.

[0009]

However, the cores 4, 9
In the first state where the optical axis alignment is performed, since the cores 4 and 9 are not coaxial at all, the axes are roughly adjusted (coarse adjustment) by visually observing from above or from the side of the connection portion 8, and the end face is adjusted. The optical signal is moved by moving the optical fiber 3 up and down and left and right with an appropriate gap provided. Since the connecting portion 8 of the waveguide type optical component 2 and the optical fiber 3 has a size of only about several 100 μm, it cannot be observed with the naked eye, and is usually positioned while enlarging using the microscope 11. I have.

A connecting device using a carbon dioxide laser beam irradiates a laser beam 7 from above toward a connecting portion 8. If the laser beam 7 is radiated to the joining portion 8 along the optical axis of the microscope, Although it is easy to observe, the carbon dioxide laser light cannot transmit through a lens (quartz) used for the microscope 11 or the like because the absorption coefficient of the carbon dioxide laser light is large for the quartz-based material.

For this reason, when observing the connection portion 8 as shown in FIGS. 4A and 4B, the microscope 11 must be removed from the optical axis of the laser beam 7 and observed obliquely. Was. As a result, when coarsely adjusting the optical axis of the waveguide type optical component 2 and the optical axis of the optical fiber 3 visually, it is not possible to accurately determine the up, down, left and right directions, and a long time has been spent. 4 (a) and 4 (b) are views showing a state of observation near a conventional connection portion.

When the irradiation position of the carbon dioxide gas laser beam 7 is determined based on an image viewed obliquely, if the height of the connecting portion 8 changes, the accurate irradiation position cannot be determined. There was also a problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to efficiently perform accurate alignment of an optical axis, and to prevent an optical fiber and a quartz-based waveguide type optical component from impeding the progress of carbon dioxide laser light at all. It is to provide a connection device及beauty method of connecting.

[0014]

According to the present invention, there is provided a connecting apparatus for connecting an optical fiber and a silica-based waveguide type optical component using a carbon dioxide laser beam.
Carbon dioxide gas even on the optical axis of the connection portion above the carbon dioxide laser light
A window for transmitting carbon dioxide gas laser light and reflecting visible light from the connection portion for observing the connection portion between the lens for condensing the laser beam and the connection portion, and providing a reflected optical axis of the window. An imaging device for monitoring the alignment between the optical axis of the optical fiber and the optical axis of the silica-based waveguide optical component is provided above. Also, the present invention
In a connection method for connecting an optical fiber and a silica-based waveguide type optical component using a carbon dioxide gas laser beam, a connection method between the optical fiber and the silica-based waveguide type optical component while transmitting the carbon dioxide laser beam is provided. The window that reflects visible light of the above is connected to a lens on the optical axis of the carbon dioxide gas laser above the connection part and that focuses the carbon dioxide laser light.
It is disposed at an angle between the connecting portions, and while irradiating the connecting portion with the carbon dioxide laser beam through the window, and monitoring the visible light from the connecting portion reflected by the window, the light of the optical fiber is monitored. An object of the present invention is to perform alignment between an axis and an optical axis of the silica-based waveguide optical component.

[0015]

According to the above construction, since the window for transmitting the carbon dioxide laser light is inclined on the optical axis of the carbon dioxide laser light, the irradiation of the carbon dioxide laser light to the connecting portion is not hindered at all, and the window is connected. Since the visible light from the unit is reflected to the imaging means and the reflected light is monitored by the imaging means,
An accurate positional relationship between the optical axis of the optical fiber and the optical axis of the silica-based waveguide optical component can be ascertained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram of one embodiment of a connecting device (hereinafter referred to as a connecting device) for connecting an optical fiber and a silica-based waveguide type optical component according to the present invention.

Referring to FIG. 1, a connecting device includes a carbon dioxide laser 22 for emitting a carbon dioxide laser beam (hereinafter referred to as a laser beam) 21a, a shutter 23 disposed on the optical axis of the carbon dioxide laser 22 and controlling the emission time of the laser beam 21a. An attenuator 24 disposed in front of the shutter 23 (right side in the figure) to control the irradiation power of the laser light 21a; The mirror 26 that reflects the light, the lens 27 that is arranged on the reflection optical axis of the mirror 26 and condenses the laser light 21a, and the condensed laser light 21b that is arranged obliquely on the emission side of the lens 27 are formed with low loss. A window 30 for transmitting the visible light from the connection unit 25 and reflecting the visible light from the connection unit 25 toward the imaging device 29;
8, a microscope 32 disposed on the emission side of the microscope 31 for photographing visible light 28, a microscope 32 connected to the camera 32, and a state near the connection portion 25, particularly, an optical axis of the optical fiber 33. And a monitor 35 for enlarging and displaying the state of alignment of the optical axis with the waveguide type optical component 34 as a visible image.

The lens 27 is made of, for example, ZnSe and has a focal length of about 20 inches.

The window 30 is a disc having a thickness of about 1 mm and a diameter of about 3.5 inches, made of germanium or silicon, and fixed at an angle of about 45 ° with respect to the optical axis of the laser beam.

The power of the laser beam 21a can be finely adjusted by an attenuator 24 so as to be optimal for connection, and the irradiation time is set by a shutter 23 to prevent excessive melting.

Next, the operation of the embodiment will be described.

The laser light 21b is placed on the optical axis of the laser light 21b.
b, the window 30 for transmitting the laser light 2
Irradiation of the connection portion 1b at the connection portion 25 is not hindered at all, and the window 3
0 reflects the visible light 28 from the connection portion 25 to the imaging device 29, and the reflected visible light 28 is reflected by the imaging device 29 in FIG.
Since the image shown in FIG.
The positional relationship between the right and left optical axes of the optical axis and the optical waveguide component 34 can be grasped, the optical fiber 33 enters the monitor light having a wavelength of about 1.31μm in the arrow P ₂ direction, the waveguide type optical component 34 A multimode optical fiber for light reception with a core diameter of about 50 μm is placed at the other end, the left and right positions of the optical fiber 33 and the waveguide type optical component 34 are adjusted while watching the monitor 35, and the optical fiber 33 is later moved up and down. Thus, the monitor light from the optical fiber 33 can be easily coupled to the waveguide type optical component 34. After the alignment is completed, the power of the laser beam is set to a predetermined value, and irradiation can be performed while observing the melting. FIG. 2 is an image near the connection portion obtained by the apparatus shown in FIG.

As described above, according to the present embodiment, the connecting portion 2
5 A window 30 that transmits the carbon dioxide laser beam 21b and reflects the visible light from the connection portion 25 is provided on the optical axis of the carbon dioxide laser beam 21b collected by the lens 27 from above, and the reflected optical axis of the window 30 is provided. Since the imaging device 29 for monitoring the alignment between the optical axis of the optical fiber 33 and the optical axis of the waveguide-type optical component 34 is provided on the upper side, accurate alignment of the optical axis can be efficiently performed, and The optical fiber 33 does not hinder the progress of the carbon dioxide laser light 21b at all.
And the silica-based waveguide type optical component 34 can be connected.

[0025]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) It is possible to obtain monitor image information in which the joint is viewed from directly above without hindering the progress of the carbon dioxide laser light.

(2) Since the right and left positional relationship between the optical fiber and the waveguide type optical component can be accurately grasped for fusion splicing, the left and right positions can be visually adjusted and the optical axis can be roughly moved only by moving up and down. Keying is possible.

(3) The required time per connection portion can be reduced, and the number of production steps and cost can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an embodiment of a connection device for connecting an optical fiber and a silica-based waveguide type optical component according to the present invention.

FIG. 2 is an image near a connection portion obtained by the apparatus shown in FIG. 1;

FIG. 3 is a view showing a state of fusion splicing of a conventional waveguide type optical component and an optical fiber.

FIGS. 4A and 4B are views showing a state of observation near a conventional connection portion.

[Explanation of symbols]

 21a, 21b Carbon dioxide gas laser beam 22 Carbon dioxide gas laser 23 Shutter 24 Attenuator 25 Connection part 26 Mirror 27 Lens 28 Visible light 29 Imaging device 30 Window 31 Microscope 32 Camera 33 Optical fiber 34 Waveguide type optical component 35 Monitor

Claims (2)

(57) [Claims] 1. A connecting device for connecting an optical fiber and a silica-based waveguide type optical component using a carbon dioxide laser beam,
Carbon dioxide gas even on the optical axis of the connection portion above the carbon dioxide laser light
A window for transmitting the carbon dioxide gas laser beam and reflecting visible light from the connection portion for observing the connection portion between the lens for condensing the laser beam and the connection portion; An imaging device for monitoring the alignment between the optical axis of the optical fiber and the optical axis of the silica-based waveguide type optical component on the reflected optical axis of the optical fiber and the silica-based waveguide. Connection device for waveguide type optical components. 2. A connecting method for connecting an optical fiber and a silica-based waveguide type optical component using a carbon dioxide laser beam,
The window for reflecting visible light, an on the optical axis of the carbon dioxide laser of the connecting portions above carbonate from the connection portion between the optical fiber and the silica-based waveguide optical components as well as transmitting the carbon dioxide laser light A laser that focuses gas laser light
The connecting portion is inclined and disposed between the lens and the connecting portion, the connecting portion is irradiated with the carbon dioxide laser beam through the window, and the light is monitored while monitoring the visible light from the connecting portion reflected by the window. A method for connecting an optical fiber and a silica-based waveguide optical component, wherein the optical axis of the fiber is aligned with the optical axis of the silica-based waveguide optical component.