Triple frequency- and phase-tunable optoelectronic oscillator based on stimulated Brillouin scattering and carrier phase-shifted single sideband modulation

A triple frequency- and phase-tunable optoelectronic oscillator based on stimulated Brillouin scattering effect and carrier phase-shifted single sideband (CPS-SSB) modulation is proposed and theoretically analyzed. In the structure, three pump lights are used to generate an oscillator signal in which the frequency is equal to triple the Brillouin frequency shift through the Brillouin gain-loss compensation. Benefiting from the wavelength-dependent characteristic of Brillouin shift, the triple frequency-tunable signal can be realized by directly tuning the laser source. The CPS-SSB modulation signal lies in the combination of a dual-parallel Mach-Zehnder modulator (DPMZM) and a tunable bandpass filter. The phase of the output microwave signal is changed by controlling the direct current bias voltage of DPMZM. Ultimately, a microwave signal, with a tunable frequency range from 26.3925 to 28.3425 GHz and a tunable phase from 0 deg to 360 deg, is obtained in theory. In addition, the theoretical simulation of the phase noise is below -110 dBc/Hz at the 10-kHz offset when tunable laser source is set at 1550 nm. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)