A Novel Optoelectronic Oscillator with Series-Coupled Double Recirculating Delay Lines

Abstract

An optoelectronic oscillator (OEO) based on series-coupled double recirculating delay lines (SC-DRDLs) is analyzed and experimentally demonstrated. The SC-DRDLs composed by the coupling cascade of two RDLs, which the free spectral range (FSR) is least common multiple of the two RDLs’ FSR, and then the large FSR can be obtained by properly setting the loop lengths of two RDLs. By consociation with the dual loops system between the dual output of the SC-DRDLs and PBS, the high sidemode suppression performance can be achieved. Meantime, the incoherence of the SC-DRDLs can be performed by using an amplified spontaneous emission (ASE) broadband laser source. An experiment is carried out. A microwave signal with high spectral purity, long-term stability, low single-sideband (SSB) phase noise is generated.