Optical Vector Analyzer Based on Double-Side Modulation With a Suppressed Carrier and Phase-Shift FBG

Abstract

A new approach to an optical vector analyzer (OVA) realization based on optical double-side modulation (ODSB) with a suppressed carrier and formation of a reference frequency, different from it, in a fiber Bragg grating with a phase shift is considered. ODSB has a higher bandwidth, allows to scan an optical device in wider frequency range on the same element base of lithium niobate, if compared to the optical single-sideband modulation (OSSB). The method is easy to implement and effective in both energy and spectrum use. The proposed OVA realization is distinguished by an extended range and high resolution of measurements, which is shown both theoretically and experimentally. The solutions to take into account the influence of the position of the PS-FBG transparency notch on the measurement accuracy based on the method of its polyharmonic sensing, which can be used for implementation in other OVA based on ODSB were proposed.