Tunable single-mode injection-locked optoelectronic oscillator with low phase-noise

Abstract

Tunable single-mode injection-locked optoelectronic oscillator (OEO) with low phase-noise is presented in this article. A master oscillator contributed by amplifier and tunable band-pass filter (TBPF) is embedded in the general single loop OEO. The oscillation frequency is determined by the center frequency of the TBPF. A portion of master oscillation signal is injected into the slave OEO loop, then it is locked by OEO signal after it passes through a long optical delay line with high Q value. With the RF isolator, the master oscillation signal with poor phase-noise is avoided directly mixing in the OEO signal. With the configuration a tunable range from 1.93 to 17.69GHz with 68dB suppression of the nearest-neighbor spur is realized. The single-sideband phase noise is below −112dBc/Hz at an offset of 10kHz within the whole tunable range. The frequency drift of the OEO system is <±2kHz within 1h. With low cost and simple system, tunable single-mode RF signal with low phase-noise and high frequency-stability is generated.