Accurate optical vector network analyzer based on optical double-sideband suppressed carrier modulation

Abstract

A high-accuracy optical vector network analysis (OVNA) based on optical suppressed carrier double-sideband (DSB) modulation and the Pound Drever Hall (PDH) technique is proposed and demonstrated. The accurate and stable frequency responses can be achieved by transmitting the optical carrier suppressed DSB modulation signals through the DUT, and then detecting the reflected signals. Compared with the traditional DSB-based OVNA, the measurement accuracy is improved by eliminating the errors caused by the even-order sidebands. Furthermore, the stability of the OVNA system can be kept by using the PDH feedback loop. An experiment is accomplished. The frequency responses of the FP interferometer are achieved with little measurement error induced by high-order sidebands, and no repeated frequency response appears even when the test time reaches up to 30 min. This novel method is simple and accurate, and would be used for charactering the symmetric ultra-high Q optical devices.