On the Combined use of Injection Locking and Optical Phase Locked Loop

Abstract

In an optical phase-lock loop (OPLL), the inherent phase noise of the laser oscillators and loop propagation delay are the restricting factor on the loop stability, frequency pulling time, loop bandwidth and loop gain. In order to be able to control these parameters, a modifed optical phase locked loop having an additional arrangement for injection synchronization and phase modulation has been proposed. Expressions for pull-in range and frequency pulling time have been derived in terms of the loop propagation delay and other parameters of the loop. Simulation results have been given in support of the analytical result.

Indexing terms:

• Optical phase locked loop
• Injection locking
• Phase error variance
• False locking
• Stability