Stability, Noise, and Nonlinear Distortion Analysis of a Sampling OPLL

The behavior of a sampling optical phase-locked loop (OPLL) is analyzed. An equivalent time invariant system model for the sampling OPLL was derived. With the help of the model, the stability of a sampling OPLL was found to depend not only on the sampling frequency but also on the duty cycle of the sampling pulse. In addition, the closed-form solutions for the sampling OPLL output noise and nonlinear distortions were also derived. The theoretical results were validated by numeric simulations.