JP2001124950A - Method for connecting temperature-independent quartz base array grating type optical waveguide element to optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for connecting a temperature-independent quartz base array grating type optical waveguide element and an optical fiber to each other, by which the connecting position of the optical fiber is automatically controlled, even if the demultiplexing wavelength characteristics of signal inputted to the optical fiber are changed. SOLUTION: In this method for aligning and connecting an optical fiber 4 to the entrance side of the temperature-independent quartz base array grating type optical waveguide element 8, the optical fiber 4 for inputting the signal light having polarized wave components is tentatively held by a fine adjustable table 5 for moving the connecting position, corresponding to electric signals and the optical signal of a center wavelength is detected from output optical signals outputted from the optical waveguide element 8. An electrical signal based on the detected optical signal is fed back to the fine adjustable table 5, and the connecting position of the optical fiber 4 is decided, and the intensity of the optical signal of the center wavelength becomes maximum. Then, the optical fiber 4 and the temperature-independent quartz base array grating type optical waveguide element 8 are connected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting a temperature-independent silica-based arrayed grating type optical waveguide device to an optical fiber, and particularly to a method of automatically aligning the core even if the wavelength characteristics of the demultiplexed light change. The present invention relates to a method for connecting a temperature-independent quartz-based array grating type optical waveguide device and an optical fiber that can be connected.

[0002]

2. Description of the Related Art A silica-based arrayed waveguide type optical module having an optical multiplexing / demultiplexing function using a wavelength division multiplexing transmission method includes athermal (temperature-independent) quartz whose demultiplexing wavelength characteristics do not depend on the ambient temperature around the module. There is one using a system array grating type optical waveguide element.

FIG. 2 is a schematic view of a general athermal quartz array grating type optical waveguide device.

As shown in FIG. 2, an athermal quartz-based array grating type optical waveguide device comprises a slab waveguide 1 and an array waveguide 2, which propagate incident light while wavelength-division into λ ₁ to λ _n . And an output waveguide 3 for propagating the light propagated for each of the wavelengths λ _{1 to} λ _{n to} the output end. The optical fiber 4 connected to the slab waveguide 1 is held by the fine moving table 5. Aligned.

In the waveguide type optical module using the athermal silica-based array grating type optical waveguide device, in the step of aligning and connecting the optical fiber 4 to the athermal quartz-based array grating type optical waveguide device, the coupling position of the optical fiber ( The branching wavelength characteristic changes depending on the connection position). Therefore, in order to manufacture a waveguide type optical module using an athermal quartz-based array grating type optical waveguide element, it is necessary to optimize the optical fiber so that the center wavelength filtering characteristic becomes a predetermined value in the alignment process of the optical fiber. It is necessary to determine the connection position (connection position).

The accuracy of the coupling position (connection position) of the optical fiber connected to the athermal silica-based array grating type optical waveguide device is defined by the International Telecommunication Union according to the wavelength separation wavelength.

[0007] For example, when the demultiplexing wavelength interval is 0.8 nm specified by the International Telecommunication Union (ITU), the coupling position (connection position) accuracy of the optical fiber connected to the waveguide element is a predetermined optimum. It must be within 0.2 μm from the position.

For this reason, in the athermal silica-based array grating type optical waveguide device, if the amount of deviation from the coupling position (connection position) of the optical fiber is within the range specified by the International Telecommunication Union, the wavelength separation wavelength is set. Different waveguide elements can be supported.

[0009]

However, when the displacement of the coupling position (connection position) of the optical fiber is larger than the range, as described above, the waveguide type using the athermal quartz array grating type optical waveguide element is used. In order to manufacture the optical module, the connection position of the optical fiber is adjusted so that the amount of displacement of the coupling position (connection position) of the optical fiber in the alignment connection process with the optical fiber is within a range of a predetermined optimum position accuracy. Had to fix. Therefore, there has been a demand for a proposal of a method capable of automatically controlling the alignment connection of an optical fiber to an athermal quartz-based array grating type optical waveguide device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a temperature-independent quartz-based array grating which can automatically control the connection position of an optical fiber even if the demultiplexing wavelength characteristic of the signal light input to the optical fiber changes. An object of the present invention is to provide a method for connecting an optical waveguide element and an optical fiber.

[0011]

According to a first aspect of the present invention, there is provided a method for aligning and connecting an optical fiber to an incident side of a temperature-independent quartz-based array grating type optical waveguide device. The optical fiber to which the signal light having the polarization component is input is temporarily held on a fine adjustment table whose connection position is moved in accordance with the electric signal, and the output optical signal is output from the optical waveguide element. Detects the central wavelength optical signal,
An electric signal based on the detected optical signal is fed back to the fine moving table, and the connection position of the optical fiber is determined so that the intensity of the optical signal of the center wavelength is maximized. This is a method of connecting an independent silica-based array lattice type optical waveguide element.

A second aspect of the present invention is a method for monitoring the wavelength of the output optical signal by using a high-resolution wavelength counter.

According to a third aspect of the present invention, there is provided a method for monitoring the center wavelength of the output optical signal using a polarization dependence measuring device for measuring polarization dependence.

According to a fourth aspect of the present invention, a computer calculates an amount of deviation from an optimum connection position of the optical fiber based on signals from the high-resolution wavelength counter and the polarization dependence measuring device, and calculates the result. A method of centering the optical fiber by feeding back to the fine movement table.

According to the above arrangement, the wavelength of the output optical signal output from the output waveguide is constantly monitored, and the polarization component of the output optical signal output from the output waveguide is monitored. Is output to the computer.
After detecting the center wavelength from these monitoring results, the computer calculates the shift amount of the connection position of the optical fiber, converts the calculation result into a feedback signal, and transmits the feedback signal to the fine moving table. This feedback signal is input to the fine adjustment table,
Based on the signal, the core of the optical fiber is moved to an optimal connection position.

[0016]

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The athermal silica-based array grating type optical waveguide device used in the present invention is the same device as that described in the prior art.

FIG. 1 is a schematic diagram showing a system for connecting an athermal quartz-based arrayed grating type optical waveguide device and an optical fiber according to an embodiment of the present invention.

As shown in FIG. 1, this system comprises an input side optical fiber 4 connected to the input side of an athermal silica-based array grating type optical waveguide element, and the input side optical fiber 4
A light source 6 for outputting a signal light having a polarization component, a fine moving table 5 for holding the input optical fiber 4 and moving the input optical fiber 4 in accordance with an electric signal, and the fine moving table 5 And a control system for controlling the input side optical fiber 4 to an optimum position.

The control system includes an alignment body 9 for accommodating the athermal quartz array grating type optical waveguide element 8 and the fine adjustment table 5, and a wavelength of λ _{n / 2} of the athermal quartz array grating type optical waveguide element 8. And a high-resolution wavelength counter 7 to which an output optical signal output from the athermal silica-based array lattice type optical waveguide element 8 through the output side optical fiber 12 is connected. A polarization dependency measuring device (PDL meter: Polarization Dep) to which an output optical signal is input through the high resolution wavelength counter 7
An endent loss meter 11 and a computer 10 that receives signals from the high-resolution wavelength counter 7 and the PDL meter 11 and controls the fine moving table based on these signals.

The high resolution wavelength counter 7 monitors and counts the wavelength of the optical signal input thereto, and the PDL meter 11 measures the polarization dependence of the input optical signal.

The computer 10 also has software for detecting the center wavelength of the output optical signal based on the monitoring results from the high-resolution wavelength counter 7 and the PDL meter 11, and input-side light based on the detected center wavelength. A software for calculating the amount of deviation of the fiber 4 from the optimal connection position, converting the result into a feedback signal, and feeding it back to the fine moving table 5 is built in.

Next, a method of connecting the athermal quartz-based array grating type optical waveguide device 8 and the optical fiber 4 according to the present invention using this system will be described.

In the optical fiber alignment connection step, first, the alignment of the optical fiber 4 to be connected and the slab waveguide 1 of the athermal quartz-based array grating type optical waveguide element 8 is performed.

At the time of this alignment, an optical fiber (input side optical fiber) 4 to be connected is attached to a fine moving table 5, and a signal light having a polarization component is output from the light source 6 to the input side optical fiber 4.

An optical signal incident from the light source 6 through the input-side optical fiber 4 to the athermal silica-based arrayed grating type optical waveguide device 8 is propagated through the athermal quartz-based arrayed grating type optical waveguide device 8 so that the wavelength is reduced. Waved.

Of the wavelength-demultiplexed optical signals, the output optical signal output from the output terminal having the wavelength λ _{n / 2} passes through the output-side optical fiber 12 and enters the high-resolution wavelength counter 7.

After measuring (monitoring) the wavelength of the incident output optical signal, the high resolution wavelength counter 7 outputs the measurement result to the computer 10 and outputs the output optical signal to the PD.
Output to L meter 11.

The PDL meter 11 measures the polarization dependency of the incident output optical signal, and outputs the measurement result to the computer 10.

The computer 10 accurately calculates the center wavelength of the optical signal output from the athermal quartz array grating type optical waveguide device 8 based on the measurement results taken from the high resolution wavelength counter 7 and the PDL meter 11, The shift amount of the optical fiber 4 from the optimal connection position is calculated.
Then, according to the amount of the shift, the fine moving table 5 is adjusted so that the intensity of the optical signal output from the output terminal having the wavelength of λ _{n / 2} becomes maximum.
Is generated and output to the fine moving table 5.

Then, by inputting a feedback signal to the fine adjustment table 5, the optical fiber 4 is moved to an optimum connection position and aligned.

Thereafter, by connecting the optical fiber 4 and the athermal quartz-based array grating type optical waveguide device 8,
The coupling of the optical fiber 4 according to the actual demultiplexing wavelength characteristic becomes possible.

[0033]

In summary, according to the present invention, when an optical fiber is connected to an athermal quartz-based array grating type optical waveguide device, the connection position of the optical fiber is output from the athermal quartz-based array grating type optical waveguide device. It is possible to control according to the central wavelength of light, and desired wavelength characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a method for connecting an athermal silica-based array grating type optical waveguide device and an optical fiber according to the present invention.

FIG. 2 is a schematic view of a general athermal quartz-based array grating type optical waveguide device.

[Explanation of symbols]

 Reference Signs List 4 incident side optical fiber 5 fine moving table 7 wavelength counter 8 athermal silica based array lattice type optical waveguide element 10 computer 11 PDL meter 12 output side optical fiber

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsu Takasugi 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture Within the Opto-System Research Laboratory, Hitachi Cable, Ltd. (72) Inventor Naoto Uezuka Hidaka, Hitachi City, Ibaraki Prefecture 5-1-1, Machi-cho Hitachi Cable, Ltd. Optro System Laboratory F-term (reference) 2H037 BA35 DA04 DA22

Claims (4)

[Claims] In a method of aligning and connecting an optical fiber to an incident side of a temperature-independent quartz-based arrayed grating type optical waveguide element, an optical fiber to which signal light having a polarization component is input is connected to an electric signal. The connection position is temporarily held by a fine moving table which moves according to the above, a light signal of a center wavelength is detected from the output light signals output from the optical waveguide element, and an electric signal based on the detected light signal is detected. After the signal is fed back to the fine adjustment table and the connection position of the optical fiber is determined so that the intensity of the optical signal of the center wavelength is maximized, the optical fiber and the temperature-independent quartz-based array-type optical waveguide are determined. A method of connecting a temperature-independent quartz-based arrayed grating type optical waveguide element for connecting a waveguide element to an optical fiber. 2. The method according to claim 1, wherein the wavelength of the output optical signal is monitored by a high-resolution wavelength counter. 3. The temperature-independent silica-based arrayed grating type optical waveguide device and optical fiber according to claim 1, wherein the central wavelength of the output optical signal is monitored by a polarization dependence measuring device for measuring polarization dependence. Connection method. 4. A computer calculates an amount of deviation from an optimal position of the optical fiber based on signals from the high resolution wavelength counter and the polarization dependence measuring device, and feeds back the result to the fine moving table. 2. The method of connecting a temperature-independent quartz-based arrayed grating type optical waveguide device and an optical fiber according to claim 1, wherein the optical fiber is aligned with the optical fiber.