Zhang Jiahong, Wang Yao, Ding Qihong
Appl Opt. 2024 Jan 20;63(3):566-574. doi: 10.1364/AO.505601.
In this paper, a single-loop tunable parity-time (PT) symmetric optoelectronic oscillator (OEO) based on a dual-mode optical phase modulator (PM) and a microwave photonic filter (MPF) has been proposed, analyzed, and designed. By adjusting the polarization angle between the input linearly polarized light and the axis of the PM, the two-mode splitting ratio of the PM can be controlled, which results in a PT-symmetric structure based on a single physical loop. By adjusting the pump light wavelength, the center frequency of the stimulated Brillouin scattering (SBS)-based MPF can be tuned, which enables a fine tunable output frequency. The results reveal that, by adjusting the pump light wavelength with a step size of 0.0001 nm, a frequency tuning accuracy of 12.5 MHz can be obtained. Simultaneously, the OEO output frequency can be tuned from 0.9 to 22 GHz, while the side-mode suppress ratio (SMSR) is 53 dB, and the phase noise is -133.8 / at a frequency offset of 10 kHz.
本文提出、分析并设计了一种基于双模光相位调制器（PM）和微波光子滤波器（MPF）的单环可调谐奇偶时间（PT）对称光电振荡器（OEO）。通过调整输入线偏振光与PM轴之间的偏振角，可以控制PM的双模分裂比，从而基于单个物理环路形成PT对称结构。通过调整泵浦光波长，可以调谐基于受激布里渊散射（SBS）的MPF的中心频率，从而实现精细的输出频率可调谐。结果表明，通过以0.0001 nm的步长调整泵浦光波长，可以获得12.5 MHz的频率调谐精度。同时，OEO输出频率可在0.9至22 GHz范围内调谐，边模抑制比（SMSR）为53 dB，在10 kHz频率偏移处的相位噪声为-133.8 / 。
