Parity-Time-Symmetric Optoelectronic Oscillator Based on DPMZM With Single-Sideband Suppressed-Carrier Modulation

A Parity-time (PT) symmetric optoelectronic oscillator (OEO) based on dual-parallel Mach-Zehnder modulator (DPMZM) with single-sideband suppressed-carrier modulation is proposed and experimentally demonstrated. PT symmetry is realized in a single physical loop, where the gain and loss loops are formed by the beating between the optical carrier and the ±1st-order sideband. By adjusting the bias point voltage of the DPMZM, the gain and loss can be balanced to achieve single-mode oscillation. In our experiment, the system produces a microwave signal with a frequency of 10.79 GHz, which phase noise is about −111dBc/Hz when the offset frequency is 10kHz.