High-Accuracy Optical Vector Analysis Based on Dual-Polarization MZM and Polarization Control

A high-accuracy optical vector analysis (OVA) based on dual-polarization MZM (DPol-MZM) and polarization control is proposed and demonstrated via simulation. By applying the DPol-MZM and adjusting the polarization control module, a linearly polarized optical single-sideband (OSSB) signal with various phase shifts between the swept sidebands and the carrier is achieved. Two measurements are implemented by transmitting the linear polarized OSSB signal through an optical device under test (DUT). The accurate frequency responses of the DUT can be obtained by processing the results of the two measurements. The error caused by the beating between each order sideband signal under the large modulation index can be effectively eliminated without reducing the dynamic range; this shows an improvement in the accuracy over that of the conventional OSSB-based OVA. In the simulation, the frequency responses of the uniform fiber Bragg grating with a bandwidth of 50 GHz can be accurately measured with a resolution of 1 MHz.