Parity-time symmetric coupled optoelectronic oscillator using a
polarization-dependent spatial structure
Abstract
We propose and experimentally investigate a parity-time (PT) symmetric
coupled optoelectronic oscillator (COEO) based on a
polarization-dependent spatial structure. In such a COEO system, the
gain/loss and coupling coefficients of two orthogonal-polarization
optical waves can be controlled by adjusting the polarization controller
(PC) and the bias voltage of the Mach-Zehnder Modulator (MZM). The
single-mode selection can be implemented by the PT symmetry breaking of
a special mode. The performance of the proposed COEO is experimentally
examined, and a 10.0 GHz microwave signal with a phase noise of −109.1
dBc/Hz @10 kHz and a side mode suppression ratio of 51.4 dB is
generated.