Adjustable testing setup for a single-loop optoelectronic oscillator with an electrical bandpass filter

Abstract

In this paper we present a novel method to measure the free spectral range (FSR) and side-mode suppressionratio (SMSR) of an optoelectronic oscillator (OEO) by adjusting the optical fiber length using an optical path selectorand signal source analyzer. We have designed a setup for a single-loop OEO operating around 5 GHz and 10 GHz thatfeatures electrical bandpass filters for side-mode suppression. The proposed approach makes it possible to evaluate theFSR and SMSR of OEOs with different optical fiber paths without requiring the changing of fiber spools or opticalconnectors. This approach could be useful for testbeds that investigate the implementation of an OEO in a 5G radioaccess network.