Development And Implementation Of High-speed Optoelectronic Device Frequency Response Measurement System

High-speed optical-electrical devices such as electrical-optical intensity modulators,electrical-optical phase modulators,and photodetectors are widely used in optical communication links and microwave photonic systems.Their frequency domain characteristics are important indicators for measuring the operating speed and bandwidth of the system.Therefore,the measurement of device frequency response parameters is particularly critical.Most of the existing measurement methods and test platforms can only test a single device or a single frequency response parameter,and cannot solve the problem of the mutual influence of the frequency response of the optical-electrical device and the electrical-optical device.With the development of photonic integration technology,electrical-optical modulators and photodetectors are evolving towards all integration on one chip.How to realize self-calibration measurement of frequency response parameters of multiple devices in one system has always been one of the urgent problems in the industry.In this work,we combine high-speed optical-electrical devices frequency response measurement theory with virtual instrument technology to design and develop a high-speed optical-electrical device frequency response measurement system.This measurement system can realize the modulation coefficient,half-wave voltage and chirp of the electrical-optical intensity modulator based on Mach-Zehnder structure(MZM),modulation coefficients and half-wave voltages of electrical-optical phase modulators,and responsivity of photodetectors,automated and self-calibration measurement of their frequency response parameters.The main research content has the following aspects:1.We summarized the basic principles and test methods of frequency shift heterodyne,and introduced the virtual instrument development platform;2.Based on National Instrument's LabVIEW software system,we investigated the control design and hardware implementation of the high-speed optoelectronic device frequency response measurement system,and realized the drive control of the external signal generator,spectrum analyzer,and DC source in the frequency shift heterodyne interference module.We successfully verified the module hardware packaging and testability verification of the Mach-Zender(MZ)frequency shift heterodyne interferometer;3.We further designed the software procedure of the test scenario according to thetype of device under test,and controlled the software interface and the test process of the electrical-optical intensity modulator,the electrical-optical phase modulator and the photodetector,and the working sequence,control drive and data of each module are also checked.The processing was carried out by the software design and global adjustment;4.We completed the joint commission and experimental verification of the software and hardware of the automatic test system,and realized the test of modulation coefficients and half-wave voltages of an electro-optical phase modulator,the modulation coefficients,the half-wave voltages and the chirp coefficients of an electro-optical intensity modulator,and the frequency response of a photodetector.The measured results are consistent with the results obtained with the traditional method;also this measurement system solves the problem of direct measurement of electrical-optical phase modulators in the electrical domain.