CN215835400U - Optical module performance testing device - Google Patents

Abstract

The utility model discloses an optical module performance testing device, aiming at providing an optical module error code testing device which is small and light and simple and reliable to test, and the utility model is realized by the following technical scheme: the optical spectrometer adopts a box body which is provided with an optical input interface, an optical output interface, a spectrometer interface and an oscilloscope interface. The optical input interface is connected with the optical attenuator and the demultiplexer in parallel through a 1-in-2 optical splitter, the optical attenuator is directly connected with the optical output interface, the demultiplexer is connected with a 4-out-of-1 demultiplexer switch, the 4-out-of-1 demultiplexer switch is connected with the spectrometer interface and the oscilloscope interface through a 1-in-2 optical splitter, a signal generator is directly connected with an optical module golden finger interface socket through a PCB printed wire, an upper computer controls the optical attenuator through a USB bus to adjust the attenuation, the sensitivity and the spectrum of an attenuation measurement optical module are adjusted, and the performance of the optical module is tested through a self-circulation flow.

Description

Optical module performance testing device

Technical Field

The utility model relates to a 100 GBASE-QSFP 28 LR4 optical module which is applied to the fields of data centers, backbone networks and the like in the field of optical communication networks, supports a 100Gbe optical link through a single-mode optical fiber in 40G and 100G Ethernet, in particular to a testing device for testing the parameters of the 100G QSFP28 LR4 optical module used in production lines and research and development laboratories.

Background

Optical communication is becoming the core strength of communication technology due to its advantages such as low transmission loss, large information capacity, and fast transmission rate, and the application of optical modules is becoming more and more extensive. The transmission rate is accelerated, error code phenomena can be generated in a high-speed optical communication system due to the problems of attenuation, dispersion and the like, and the accurate and effective measurement of the error code rate of the optical module is of great importance. Error detectors are common instruments used to test high-speed digital (including optical communication) devices and systems. In practice, it is often necessary for the error detector to be able to test multiple channels. However, most of the currently marketed error detectors can only test the standard communication channel of the telecommunication sector. In practical tests, the code pattern generator and the error detector are often integrated together to form an important part of the error tester. An error tester generally consists of two parts, a transmitting part and a receiving part. The transmitting part sends standard data signals as test signals to the tested system instead of transmission signals in the actual line. The receiving section generates the identical data signal as the transmitting section for bit-by-bit comparison with the received signal. At present, the transmitting part of the error code tester has two realization modes, namely hardware realization and FPGA realization. In general, two of three signal lines of the error detector are signal outputs including a trigger signal (trigger) and a modulation signal (TX), and the other is a signal return input (RX), which is mainly used for analyzing an error code. Usually, the error generator generates a continuous test code element sequence, and after encoding, the continuous test code element sequence is sent to the input end of the tested system, and after passing through the channel of the tested system, the signal is received and decoded by the error detector of the error tester, so as to obtain the test code element sequence containing error codes. Comparing the test code element sequence of the receiving end with the test signal of the transmitting end code by code, if a certain code element is not consistent, the error code count is increased by one. The number of error codes in a period of time is counted, recorded and stored, the error code rate in the period of time is calculated, and the result of testing the error codes is analyzed and displayed, which is the working principle of the error code tester. The clock source needed by the error code meter of the optical module generally provides corresponding reference clocks when the error code meter tests the optical modules with different speeds, generally, the clocks are not generated simultaneously, the frequency point range is not very wide, and if multi-path clock output is required to be generated simultaneously, a clock generator is selected as a reference source. The early 100G optical module used a 10-way 10Gbps NRZ implementation, and was packaged with CDFP or CFP. The advantages are that the mature 10G NRZ technology on the 10G optical module can be used, but the defects are that 10 paths of signals are needed for parallel transmission, the power consumption and the volume are large, and the requirement of high-density networking of a data center is influenced. Through recent development, a plurality of categories of 100G optical modules have been derived, each having a different optical module standard and being suitable for different transmission applications. The QSFP28 LR4 optical module is a parallel 100G optical module providing 4 independent transmit and receive channels, and adopts a one-way 25G NRZ technology. For example, a 100G QSFP28 SR4 optical module can operate 4-way 25Gbps data within 100 meters of OM4 MMF, and the total data rate is 100 Gbps. When the 100G QSFP28 LR4 or SR4 optical module transmits signals at a transmitting end, the electric signals are converted into optical signals through a laser array and then transmitted in parallel on a ribbon multimode optical fiber, and when the optical module reaches a receiving end, a photodetector array converts the parallel optical signals into parallel electric signals. The optical module is composed of an optoelectronic device, a functional circuit, an optical interface and the like, wherein the optoelectronic device comprises a transmitting part and a receiving part. The transmitting part is: the electric signal with certain code rate is processed by an internal driving chip to drive a semiconductor Laser (LD) or a Light Emitting Diode (LED) to emit modulated optical signals with corresponding speed, and an optical power automatic control circuit is arranged in the semiconductor laser or the light emitting diode to keep the power of the output optical signals stable. The receiving part is: the optical signal with a certain code rate is input into the module and then converted into an electric signal by the optical detection diode. After passing through the preamplifier, the electric signal with corresponding code rate is output. The power consumption of the module with low power consumption and different model parameters is different, and the power consumption of the module with 100G is generally 3.5-9w according to different packages.

The parameters of an optical module are related to the performance, the service life, and the like of one optical module, and one optical module needs to be referred to as the following indexes. Output optical power: the optical power output by the module under the normal working condition of the module; emission eye diagram: inputting the transmitted waveform into a vertical amplifier of an oscilloscope, synchronizing the period of a sawtooth wave generating horizontal scanning with the timing of a code element, and observing an image similar to human eyes on the oscilloscope, which is called an eye pattern; center wavelength: connecting wavelengths corresponding to the key points of the line segments with the maximum amplitude values of 50% in the emission spectrum; side mode suppression ratio: in the emission spectrum, the ratio of the (dynamic) highest spectral intensity to the sub-high spectral intensity under normal operating conditions; spectrum width: the maximum spectral width when the maximum peak value of the center wavelength of the main mode falls to-20 dB; extinction ratio: the minimum value of the ratio of the average optical power of the signal to the average optical power of the null signal under the full modulation condition; optical power after shutdown: the TxDisable pin of the module is set to a corresponding level, the module switches off a laser driving circuit of the module, and the output optical power of the module is the optical power of the module after the switching off; transmission cost: the degree of performance degradation of the modular transmitter after transmission of a particular length of optical fiber; reception sensitivity: under the condition of a certain bit error rate, the minimum input average optical power which can be received by the receiving component; saturated optical power: under the condition of a certain bit error rate, the maximum input average optical power which can be received by the receiving component; no light alarm is given: changing the input optical power of an input module from large to small or from small to large at the working speed of an optical module, and when the optical power is changed to a certain value, the optical power of the module when the alarm output signal level is reversed; alarm hysteresis: difference of alarm signal threshold. The 100G QSFP28 LR4 optical module is 4-path LANWDM signal transmission, so that the quality condition of each path of signal needs to be tested when the performance of the optical module is tested, and if the optical module is tested by a discrete testing instrument, the test is complicated, and the test platform is huge and is very inconvenient.

With the rapid batch application of 100G optical modules, the cost pressure is getting larger, how to effectively reduce the cost of expensive manufacturing test equipment of 100G optical modules and improve the test efficiency becomes an increasingly urgent problem. In practical application, because the length of fiber link is various, and test equipment is various, and the station occupies a large amount of spaces, and a large amount of RF test cables, the dismouting is wasted time and energy, and it is troublesome to trade the line, and very easily appears connecting reliability problem, influences efficiency, and total investment cost is high. Secondly, the software has various types and complex programming, and the software is troublesome to switch during actual test, thereby influencing the test efficiency. The conventional 100g optical module test system is far from meeting the need to deploy a data center in the most cost effective manner.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects in the prior art, provides a 100G QSFP28 LR4 optical module performance testing device which is small, light, simple, reliable and efficient, and provides a very convenient parameter testing device for production testing and research and development testing of a 100G QSFP28 LR4 optical module.

The technical scheme adopted by the utility model for solving the technical problem is that the optical module performance testing device comprises: the utility model provides a box body of light input interface, light output interface, spectrum appearance interface and oscilloscope interface, the error code analyzer through light input interface connection, its characterized in that: the optical input interface is connected with the optical attenuator and the demultiplexer in parallel through a 1-in-2 optical splitter, the optical attenuator is directly connected with the optical output interface, the demultiplexer is connected with a 4-out-of-1 demultiplexer switch, the 4-out-of-1 demultiplexer switch is connected with the spectrometer interface and the oscilloscope interface through a 1-in-2 optical splitter, a signal generator is directly connected with an optical module golden finger interface socket through a PCB printed wire, an upper computer controls the optical attenuator through a USB bus to adjust the attenuation, the sensitivity and the spectrum of an attenuation measurement optical module are adjusted, and the performance of the optical module is tested through a self-circulation flow.

Compared with the prior art, the utility model has the following beneficial effects:

the body is small and light. The utility model adopts a shell with four interfaces, namely an optical input interface, an optical output interface, a spectrometer interface, an oscilloscope interface and a shell, wherein the optical input interface is connected with an optical attenuator in parallel through 1-to-2 optical splitters and a 4-to-1 wave-splitting optical switch to form an optical module performance testing device, and the device is few, simple in structure, small in size and light in weight. The defects of large test platform and great inconvenience are overcome. And the signal generator uses the mode that PCB printed lines are directly connected with the optical module golden finger interface socket to replace the mode that a large number of RF cables are connected in the traditional scheme, thereby ensuring the high reliability of the platform. Meanwhile, the platform is very fast to build and disassemble, and time and labor cost are saved.

The test is simple and reliable. The optical input interface is connected with an optical attenuator and a 1-out-of-4 (selected 1) wave-breaking optical switch in parallel through a 1-in-2 optical splitter, the optical attenuator is directly connected with the optical output interface, the spectrometer interface is connected with an oscilloscope interface in parallel, and the 1-out-of-4 (selected 1) optical switch connected with the 1-in-2 optical splitter is connected with the 1-out-of-4 wave-breaking optical switch, so that the self-loop flow test, the sensitivity test or the long-fiber test can be performed; the self-loop sensitivity test, the long fiber test, the flow test and the spectrum test can be completed. The optical switch can manually set an opened channel, and can also select the opened channel by using upper computer software through a USB bus, and the selected channel can simultaneously carry out spectrum test and optical eye pattern related parameter test. The size of the attenuation can be controlled by an upper computer through a USB bus, and the sensitivity of 100G QSFP28 LR4 can be measured by adjusting the attenuation of an attenuator. The test process is very simple and the test is reliable.

The utility model has great improvement space subsequently to meet the requirements of different optical modules. For example, the test device can be directly used on 100G QSFP28 ER4 and 100G QSFP28 SR4 optical modules; the testing device can be used for 100G QSFP28 CWDM4 optical module testing by replacing the LAN-WDM 4 wave-selective 1 optical demultiplexer switch with a CWDM4 wave-selective 1 optical demultiplexer switch; the test device can also perform 50G QSFP56 PAM4 optical module test by using an oscilloscope supporting PAM4 eye diagram. Therefore, the testing device has wide applicability and great flexibility.

The signal generator of the test system can also be independently used as a clock recovery device, and 3 million dollars are needed for a 25G rate clock recovery device which is purchased from outsourcing.

Drawings

Fig. 1 is a schematic diagram of the working principle of the optical module performance testing device of the present invention.

Detailed Description

See fig. 1. In a preferred embodiment described below, a light module performance testing apparatus includes: the utility model provides a box body of light input interface, light output interface, spectrum appearance interface and oscilloscope interface, the error code analyzer through light input interface connection, its characterized in that: the optical input interface is connected with the optical attenuator and the demultiplexer in parallel through a 1-in-2 optical splitter, the optical attenuator is directly connected with the optical output interface, the demultiplexer is connected with a 4-out-of-1 demultiplexer switch, the 4-out-of-1 demultiplexer switch is connected with the spectrometer interface and the oscilloscope interface through a 1-in-2 optical splitter, a signal generator is directly connected with an optical module golden finger interface socket through a PCB printed wire, an upper computer controls the optical attenuator through a USB bus to adjust the attenuation, the sensitivity and the spectrum of an attenuation measurement optical module are adjusted, and the performance of the optical module is tested through a self-circulation flow. The optical input interface can connect the luminous input of the 100G QSFP28 LR4 optical module to the optical attenuator and the 1-out-of-4 wave-demodulation optical switch; the optical output interface may output a portion of the power. The spectrometer interface and the oscilloscope interface can be used for the optical module to carry out self-loop flow test, sensitivity test or long fiber test; the testing of the spectrum can be performed through the spectrometer interface.

The wavelength division demultiplexer CWDM is a Wavelength Division Multiplexer (WDM) for reflection, the WDM is a wavelength division multiplexer facing the low-cost WDM transmission technology of the metropolitan area network access layer, the optical multiplexer is used to multiplex the optical signals with different wavelengths to a single optical fiber for transmission, and at the receiving end of the link, the optical demultiplexer is used to decompose the mixed signals in the optical fiber into signals with different wavelengths, and the signals are connected to corresponding receiving equipment. The wavelength division multiplexer transmitting end combines signals of a plurality of wavelengths together and injects the signals into a transmission optical fiber.

The optical signal of the 100G QSFP28 LR4 optical module comprises 4 wavelengths of LAN-WDM waves, wherein the wavelengths are 1294.53nm-1296.59nm,1299.02nm-1301.09nm,1303.54nm-1305.63nm and 1309.09nm-1310.19nm, the four wavelengths are analyzed and switched on through a 4-to-1 wave-splitting optical switch, and the four wavelengths are respectively connected to the 4-to-1 optical switch through four independent optical fibers. The 4-to-1 optical switch can manually set the opened channel, and can also select the opened channel by using upper computer software through a USB bus, and the selected channel can be used for spectrum testing.

The embodiments of the present invention have been described in detail, and the present invention has been described with reference to the specific embodiments thereof; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and application scope, and in summary, the contents of the embodiments in the present specification should not be construed as limiting the present invention.

Claims (7)

1. An optical module performance testing device, comprising: the utility model provides a box body of light input interface, light output interface, spectrum appearance interface and oscilloscope interface, the error code analyzer through light input interface connection, its characterized in that: the optical input interface is connected with the optical attenuator and the demultiplexer in parallel through a 1-in-2 optical splitter, the optical attenuator is directly connected with the optical output interface, the demultiplexer is connected with a 4-out-of-1 demultiplexer switch, the 4-out-of-1 demultiplexer switch is connected with the spectrometer interface and the oscilloscope interface through a 1-in-2 optical splitter, a signal generator is directly connected with an optical module golden finger interface socket through a PCB printed wire, an upper computer controls the optical attenuator through a USB bus to adjust the attenuation, the sensitivity and the spectrum of an attenuation measurement optical module are adjusted, and the performance of the optical module is tested through a self-circulation flow.

2. The optical module performance test apparatus according to claim 1, wherein: the optical input interface connects the light emitting input of the 100G QSFP28 LR4 optical module to an optical attenuator and a 1-out-of-4 demultiplexer optical switch.

3. The optical module performance test apparatus according to claim 1, wherein: the optical output interface outputs part of the power.

4. The optical module performance test apparatus according to claim 1, wherein: the spectrometer interface and the oscilloscope interface are used for the optical module to carry out self-loop flow test, sensitivity test or long fiber test.

5. The optical module performance test apparatus according to claim 1, wherein: the testing of the spectrum can be performed through the spectrometer interface.

6. The optical module performance test apparatus according to claim 2, wherein: four wavelengths of the 100G QSFP28 LR4 optical module are analyzed by a 4-to-1 wave-demodulating optical switch, and are respectively connected to the 4-to-1 optical switch through four independent optical fibers.

7. The optical module performance test apparatus according to claim 2, wherein: and (4) manually setting the opened channel by using the 1-out-of-4 optical switch, or selectively opening the channel by using upper computer software through a USB bus to perform spectrum test on the selected channel.

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