CN1548931A - An automatic test device and method for a comb filter spectrum optical module - Google Patents

Abstract

The present invention proposes an automatic testing device and method for a comb filter spectrum light module, the device includes a wide-spectrum light source and a spectrum analyzer, and further includes: a beam splitter, used to divide the wide-spectrum optical signal into spectrum The multi-channel wide-spectrum optical signals with the same type and the same or similar optical power; the optical switch is used to switch and output the input multi-channel optical signals; the computer is used to control the above devices and process and analyze the received data. The present invention can complete the automatic test of the performance index of the comb filter spectrum light module. Using the interface provided by the spectrum analyzer with the computer, all operations and data processing and analysis can be automatically controlled by the computer, and the channel performance and isolation can be accurately and quickly measured. , so that the test efficiency is greatly improved, and the operation is simple and clear.

Description

An automatic test device and method for a comb filter spectrum optical module

technical field

The invention relates to the technical field of optical transmission, in particular to an automatic testing device and method for a comb filter spectrum optical module.

Background technique

Since the 1990s, with the continuous increase in the amount of transmitted data, the traditional cable transmission method can no longer meet the requirements, so the optical transmission method with large transmission capacity and low cost has been widely used.

In existing optical transmission technologies, in order to make full use of bandwidth resources, WDM (Wavelength Division Multiplexing: wavelength division multiplexing) or DWDM (DenseWavelength Division Multiplexing: dense wavelength division multiplexing) is used for signal transmission.

In an optical transmission system using WDM or DWDM, a very important core device is an optical module with a comb filter spectrum, such as a multiplexer and demultiplexer (mux/demux), Interleaver, etc., to ensure that the optical transmission system The stable operation and perfect performance of the above-mentioned optical modules are very necessary to perform strict and perfect performance tests before they are put into use.

At present, the test technology is based on the spectrum analyzer and is tested manually. The specific test steps are as follows:

(1) Setting the wavelength calibration and measurement parameters of the spectrum analyzer;

(2) Activate the first channel of the spectrum analyzer, input the broadband light source into the spectrum analyzer, and measure the optical power spectrum of the input light source;

(3) Connect the wide-spectrum light source to the total input port of the optical module to be tested, and connect the output port of the channel to be tested to the spectrum analyzer, activate the second channel of the spectrum analyzer, and measure the output of the channel;

(4) Activate the third channel of the spectrum analyzer, and use the relevant parameters and output results of the first channel and the second channel to calculate the loss spectrum in the third channel;

(5) Measure the insertion loss and the maximum insertion loss difference at the peak wavelength;

(6) Measure the central wavelength of the 3dB bandwidth;

(7) Measure ndB bandwidth;

(8) After reading all the performance indicators of a channel, perform the tests from (5) to (7) on the subsequent channels according to the content displayed on the spectrometer until all channels of the optical module to be tested are tested.

Obviously, there are many deficiencies in the above technologies, mainly including:

1. The automatic test of the optical module to be tested cannot be realized, and all indicators such as insertion loss, 3dB center wavelength, nDB bandwidth, and differential loss variation range cannot be tested at one time, and each channel of the optical module to be tested must be tested sequentially, which costs plenty of time;

2. The test result data cannot be automatically analyzed and compared, and manual calculation, analysis and comparison are required, which takes a lot of time and manpower.

technical content

The invention proposes an automatic testing device and method for a comb filter spectrum optical module to solve the problem of low automation in the prior art.

In order to solve the above problems, the present invention provides the following technical solutions:

An automatic testing device for a comb-filtered spectral light module, including a wide-spectrum light source and a spectrum analyzer, wherein the device further includes:

The optical splitter is used to divide the wide-spectrum optical signal into multiple wide-spectrum optical signals with the same spectrum type and the same or similar optical power;

The optical switch is used to switch and output the input multi-channel optical signals;

A computer for controlling the above-mentioned devices and processing and analyzing the received data;

The computer controls the wide-spectrum light source, optical switch and spectrum analyzer respectively, and the wide-spectrum optical signal emitted by the wide-spectrum light source enters the optical splitter and is divided into multiple channels with the same spectrum type and the same or similar optical power. Spectrum optical signal, wherein one wide-spectrum optical signal is input to the optical module to be tested, and the other wide-spectrum optical signal is input to the optical switch, and the optical module to be tested processes the input wide-spectrum optical signal and outputs it to the An optical switch, the optical switch switches the input multi-channel optical signals, one of the optical signals is input to the spectrum analyzer, the spectrum analyzer analyzes it, and the test data is output to the computer for processing .

Above-mentioned device also further comprises:

A coupler-type multiplexer, which is used to combine multiple optical signals of a single-peak filter spectrum into one optical signal of a multi-peak filter spectrum;

Multiple channels of single-peak filter spectrum optical signals output by the optical module to be tested enter the coupler-type multiplexer to be combined into one channel of multi-peak filter spectrum optical signals, and are input to the optical switch for switching.

An automatic testing method for a comb filter spectrum optical module, comprising the following steps:

a. The optical module to be tested receives a wide-spectrum optical signal and outputs multiple optical signals;

b. The spectrum analyzer measures and compares the wide-spectrum optical signal input by the optical module to be measured and the optical signal output by each channel respectively, and sends the test data to the computer;

c. The computer processes and analyzes the test data to obtain the analysis results.

Before the step a, it further includes: initializing the automatic test system.

Step ab is also included between said step a and said step b:

ab. Combining the multi-channel optical signal output of the optical module to be tested into a multi-peak optical signal output.

The analysis result in step c specifically refers to one or more of peak insertion loss, center wavelength, ITU-T center wavelength, center wavelength offset, nDB bandwidth, and adjacent channel crosstalk.

By adopting the technical scheme of the present invention, not only can the automatic test of the performance of the optical module with comb filter spectrum be completed, but also the interface with the computer provided by the spectrum analyzer can be used to realize that all operations and data processing and analysis are all automatically controlled by the computer, As long as the user selects the specific optical module type and test index, the channel performance and isolation can be accurately and quickly measured, and the record of the relevant index and the test conclusion of whether the standard is met can be output, and it can be pointed out which index does not meet the requirements, thereby shortening the test. time, the test efficiency is greatly improved, the test is automatically completed, and the test of all channels can be completed at one time, and the channel characteristics of all channels can be recorded and analyzed at one time, making the operation simple and clear.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific implementations.

Description of drawings

FIG. 1 is a hardware configuration diagram of an automatic test device for a comb filter spectrum optical module according to an embodiment of the present invention;

2 is a flowchart of an automatic testing method for a comb-filtered spectrum optical module according to an embodiment of the present invention;

Fig. 3 is a hardware configuration diagram of an automatic test device for a comb filter spectrum optical module according to another embodiment of the present invention.

Specific implementation

As shown in Figure 1, it is an automatic test device for a comb filter spectrum optical module according to an embodiment of the present invention, and its composition includes:

Broad-spectrum light source 1, used to provide wide-spectrum optical signals required for testing;

50:50 optical splitter 2, used to divide the wide-spectrum optical signal into two broad-spectrum optical signals with the same spectrum type and the same or similar optical power;

1*4 optical switch 3, used to switch and output the 4 input optical signals;

The spectrum analyzer 4 is used to test the performance index of the input optical signal;

Computer 5, used to control the above-mentioned devices and process and analyze the received data;

The coupler-type multiplexers 6 and 7 are used to combine multiple channels of optical signals with a single-peak filter spectrum into one optical signal with a multi-peak filter spectrum.

This embodiment is used to test the performance index of an optical module with a comb filter spectrum. In this embodiment, the optical module with a comb filter spectrum to be tested uses a multiplexer and a demultiplexer (MUX/DEMUX). The input terminal of MUX/DEMUX is connected to an output port of 50:50 optical splitter 2 in this embodiment, and the outputs of 1, 3, 5...39 odd-numbered channels of MUX/DEMUX are respectively connected to the coupler type multiplexer 6, connect the outputs of 2, 4, 6...40 even-numbered channels to the input of the coupler-type multiplexer 7 respectively.

As shown in Figure 2, an automatic testing method for a comb filter spectrum optical module used in this embodiment includes the following steps:

1. Initialize the automatic test system.

That is, the automatic test device of the comb filter spectrum optical module of this embodiment is initialized, specifically including the following links:

First, calibrate the power difference between the output terminals used by the coupler-type multiplexers 6 and 7. In order to obtain high-precision test data, manual calibration must be performed on the coupler-type multiplexers. Specifically, it is divided into the following steps: 1. The mux/demux module to be tested is removed, and an output terminal out1 of the optical splitter 2 is directly connected to the first input channel of the coupler type multiplexer 6 or 7, and an optical switch is used 3 Collect and analyze the input and output spectra of the channel measured by the coupler-type multiplexer 6 or 7 with the spectrum analyzer 4 to obtain the insertion loss spectrum of this channel. The insertion loss refers to the optical channel with input and output ports, the difference between the input light and the output light power; because the insertion loss corresponding to different input light wavelengths is different, the corresponding curve of the input light wavelength and insertion loss is called insertion. Loss Spectrum. The method of calculating the insertion loss spectrum is to subtract the input spectrum from the output spectrum, but the operation of this embodiment is completely controlled by the software, as long as the optical path is connected correctly, the software can be started.

2. After the software is processed, it prompts to calibrate the next channel, change the optical path connection, connect the output terminal out1 of the optical splitter 2 directly to the second input channel of the coupler-type multiplexer 6 or 7, and calculate the insertion loss Spectrum...and so on, calculate the insertion loss spectrum of all input channels.

3. After you have the insertion loss spectrum of all the input channels, start the software, and calculate the corresponding insertion loss according to the working wavelength of each channel of the coupler type combiner 6 or 7, and form a correction parameter table. One of the contents is the insertion loss list for each channel of the coupler-type multiplexer 6 or 7.

Secondly, test the power difference of the spectrum type at two ports (out1 and out2) of the 50:50 spectrometer 2 with the spectrum analyzer 4, and record it in the calibration table;

Finally, control the spectrum analyzer 4 with the computer 5 to complete the wavelength calibration and measurement parameter settings,

Specifically, it is divided into the following steps:

1. Connect the calibrator light source of the spectrum analyzer 4 to the 1*4 optical switch 3, connect the 1*4 optical switch to the light source, and input it to the spectrum analyzer for self-calibration;

2. Select the following menu items through the buttons: Wavelength, Reference Level, Scale/Div, Senditivity; and then enter the specific parameters in the digital input area on the panel, and press the ENTER key to confirm.

3. Select the following menu items through the buttons: RBW, VBW; and then enter the specific parameters in the digital input area on the panel, and press the ENTER key to confirm.

2. The optical module to be tested receives a wide-spectrum optical signal and outputs multiple optical signals;

The computer 5 controls the wide-spectrum light source 1 to emit light, and the wide-spectrum optical signal emitted by the wide-spectrum light source 1 enters the 50:50 splitter 2 and is divided into two broad-spectrum optical signals with the same spectrum type and the same or similar optical power. The spectral optical signal is input to the 1*4 optical switch 3, and the other wide-spectrum optical signal is input to the optical module MUX/DEMUX to be tested, and the optical module MUX/DEMUX to be tested processes the input broadband optical signal and filters it into 40 channels of single-peak filtered optical signals are output by 40 channels of the optical module MUX/DEMUX to be tested.

3. Combining the multi-channel optical signal output of the optical module to be tested into a multi-peak optical signal output.

Connect the single-peak filter spectrum optical signals output by the odd-numbered channels of the optical module MUX/DEMUX to be tested to the coupler-type multiplexer 6 to combine them into one multi-peak filter spectrum optical signal, and input them to the 1*4 optical switch 3 Switching is performed, and the optical signals of the single-peak filter spectrum output by each even-numbered channel of the optical module MUX/DEMUX to be tested are respectively connected to the coupler type combiner 7 to be combined into an optical signal of a multi-peak filter spectrum, which is also input to the 1*4 optical switch 3 for switching.

4. The spectrum analyzer measures and compares the wide-spectrum optical signal input by the optical measurement module and the optical signal output by each channel respectively, and sends the test data to the computer. Specifically divided into the following steps:

1. The computer 5 controls to turn on the 1*4 light switch 3 and connect the wide-spectrum light source, and controls to activate the "Trace B" of the spectrum analyzer 4, and sets "Update" to "On" and "View" to "Off";

2. The computer 5 controls the 1*4 optical switch 3 to connect the optical signal output by the odd channel of the optical module MUX/DEMUX to be tested through the coupler type multiplexer 6, and controls to activate the "Trace A" of the spectrum analyzer 4 to measure The output of the odd-numbered channels of the MUX/DEMUX optical module to be tested, and set "Update" to "On" and "View" to "Off";

3, computer 5 controls and activates " Trace C " of spectrometer 4, and " Update ", " View " are all " On ", and " Log C=A-B ", and " Trace C " of spectrometer 4 shows this loss spectrum of the channel;

4. Output the test data of this channel displayed by the spectrum analyzer 4 "Trace C" to the computer 5;

5. Repeat steps 1 to 4 for another channel of the MUX/DEMUX to be metered. If all channels are tested, go to step 5.

5. The computer processes and analyzes the test data and obtains the analysis results. Specifically divided into the following steps:

1. Obtain the loss spectra of the odd-numbered channels and the even-numbered channels from the test data received by the computer 5, call the calibration table generated in the initialization, and process and obtain the loss spectra used in the following steps;

2. In the loss spectrum obtained in step 1, the number of channels between the start wavelength and the end wavelength is judged by a threshold value of insertion loss, and the start wavelength and end wavelength of each complete channel are determined, along the wavelength From the short to the long direction, judge the peak insertion loss of each channel in turn;

3. Calculate the central wavelength, ITU-T central wavelength, central wavelength offset, ndB bandwidth, adjacent channel crosstalk and other performance indicators of each channel in turn;

4. Judging the processing results in the above steps 2 and 3 with the standard preset indicators to get the general conclusion: pass or fail, if not pass, the analysis data and indicators of the failed project will be given.

The central wavelength in step 2 is obtained in this way: the central wavelength in this embodiment adopts the 3dB central wavelength, that is, the value of the peak insertion loss minus 3dB is the threshold, and the wavelength of the left boundary and the right boundary of the 3dB bandwidth of each channel is determined , the average of the two is the 3dB center wavelength;

The ITU-T central wavelength is obtained in this way: the corresponding ITU-T central wavelength can be obtained by rounding the central wavelength;

The central wavelength offset is obtained as follows: the central wavelength offset is represented by the difference between the ITU-T standard wavelength and the central wavelength;

The nDB bandwidth is obtained by finding the highest point of the loss spectrum and two nDB points relative to the highest point, and the difference between the center wavelengths corresponding to the two nDB points is the nDB bandwidth. Common nDB bandwidths include -0.5dB bandwidth, -3dB bandwidth, and -20dB bandwidth.

Adjacent channel crosstalk is obtained in this way: subtract the curve data of the MUX/DEMUX odd-even channel loss spectrum of the optical module to be tested and then take the absolute value. According to the obtained ITU-T standard wavelength, take the corresponding value, which is the phase Adjacent channel crosstalk.

In practical application, the optical module to be tested with comb filter spectrum is connected to this embodiment, and the performance of each channel is automatically tested by computer control, and the test data is automatically analyzed by the corresponding analysis program in the computer to determine Whether the performance index of each channel of the optical module to be tested meets the standard.

The hardware configuration of the automatic test technology of the comb-shaped filter spectrum optical module of the present invention is not limited to the above situation. When the number of channels of the optical module to be tested is small, for example, when the optical module to be tested is an interleaver, the comb-shaped Filter the coupler-type multiplexers 6 and 7 in the automatic test device of the spectrum optical module, and directly connect the odd and even channels to the 1*4 optical switch 3, as shown in FIG. 3 .

Claims (6)

1, a kind of automatic testing equipment of comb filtering spectrum optical module includes wide spectrum light source and spectroanalysis instrument, it is characterized in that this device also further includes:

Optical splitter is used for the wide range light signal is divided into spectral pattern unanimity, multichannel wide range light signal that luminous power is identical or close;

Photoswitch is used for the multipath light signal of input is switched output;

Computing machine is used to control above-mentioned device and the data that received is carried out Treatment Analysis;

This computing machine is controlled described wide spectrum light source respectively, photoswitch and spectroanalysis instrument, the wide range light signal that is sent by this wide spectrum light source enters described optical splitter and is divided into the spectral pattern unanimity, the multichannel wide range light signal that luminous power is identical or close, wherein one have a lot of social connections the spectrum light signal import optical module to be measured, and another spectrum light signal of having a lot of social connections is input to described photoswitch, this optical module to be measured exports described photoswitch to after the wide range light signal of input is handled, this photoswitch switches the multipath light signal of input, wherein one road light signal is input to described spectroanalysis instrument, analyze by this spectroanalysis instrument, export test data to described computing machine and handle.

2, the automatic testing equipment of a kind of comb filtering spectrum optical module as claimed in claim 1 is characterized in that this device also further includes:

Coupling type wave multiplexer is used for the light signal of the unimodal filtering spectrum of multichannel is combined into the light signal of one tunnel multimodal filtering spectrum;

Enter described coupling type wave multiplexer by the light signal of the unimodal filtering spectrum of multichannel of optical module to be measured output and be combined into the light signal of one tunnel multimodal filtering spectrum, and input to described photoswitch and switch.

3, a kind of automatic test approach of comb filtering spectrum optical module is characterized in that the method includes the steps of:

A, optical module to be measured receive the wide range light signal and export multipath light signal;

B, spectroanalysis instrument are treated the wide range light signal of photometry module input respectively and the light signal of every road output is measured comparison, and test data is delivered to computing machine;

C, computing machine carry out Treatment Analysis to this test data, obtain analysis result.

4, the automatic test approach of a kind of comb filtering spectrum optical module as claimed in claim 3 is characterized in that, also further comprises before described step a: Auto-Test System is carried out initialization.

5, the automatic test approach of a kind of comb filtering spectrum optical module as claimed in claim 3 is characterized in that, also comprises step ab between described step a and described step b:

Ab, the output of the multipath light signal of optical module to be measured is combined into the output of multimodal light signal.

6, the automatic test approach of a kind of comb filtering spectrum optical module as claimed in claim 3, it is characterized in that the analysis result among the described step c specifically is meant in crosstalking one or more of peak value Insertion Loss, centre wavelength, ITU-T centre wavelength, center wavelength shift, ndB bandwidth, adjacency channel.

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