Frequency Response Tailoring of a Phase Modulated Link With Stimulated Brillouin Scattering

Abstract

Phase-modulated analog photonic links with Mach Zehnder interferometers are used for signal transport and to reduce transmitter complexity. However, the frequency response of these links suffers from dispersion-induced transmission nulls, severely limiting the operational bandwidth. To overcome this challenge, we propose a method to compensate for the transmission dips of phase-modulated links. The operating bandwidth of an analog photonic link formed by a phase modulator and a Mach Zehnder interferometer is increased by superimposing a stimulated Brillouin scattering gain response over the transmission null, resulting in compensation of the null response. The proposed approach is simulated and experimentally verified for different delays of the interferometer and multiple null compensation is also demonstrated. Tunability of the null compensation is also shown for the L, S, C, X, Ku, and Ka bands. Furthermore, link gain improvement is demonstrated through balanced detection.