Optical Vector Network Analyzer Based on Single-Sideband Modulation and Segmental Measurement

We propose an optical vector network analyzer (OVNA) based on single-sideband (SSB) modulation and segmental measurement. The motivation of this work lies in the fact that it is hard for the previous SSB-based OVNA to measure a device-under-test (DUT) with bandpass response. In our scheme, the transmission response of the DUT is divided into several segments, which are measured one by one using the SSB modulation method. The frequency interval between adjacent segments is precisely controlled by a microwave source. The full transmission response of the DUT is obtained by combining the measured results of different segments. The adjacent segments are connected using the overlapped transmission responses. A proof-of-concept experiment was carried out to measure the transmission response of an optical bandpass filter. It was successfully obtained over a frequency range of 80.05 GHz with a resolution of 25 MHz.