Optimum configuration of multiloop optoelectronic oscillators

Abstract

We are concerned with providing a generally applicable optimization method for harnessing the low-phase-noise microwave-millimeter-wave signal generation capabilities of optoelectronic oscillator (OEO) structures. The gained benefits include the possibility of using inexpensive, commercially available bandpass filters; single-mode operation; equidistant spacing of modes; and total cancellation of spurious content in the output signal. Our theoretical ascertainments and simulation data are underlined by numerous experimental results, which were gained through measurements on OEO setups containing one, two, or three parallel connected optical loops. This design method also makes it possible to improve the oscillator's performance, obviating the need for a filter of outstanding performance, ultimately of an unreachably high Q value and low thermal sensitivity.