A Low Phase Noise 10 GHz To 2 THz Continuously Tunable Optical Microwave Source By Optical Injection

Abstract

Introduction: The generation of optical microwave carriers is gaining growing interest because a wide range of frequencies can be attained and a low loss transport via optical fibers is possible. Most schemes published so far, lack continuous tunability, or need injection of electrical microwave signals or sophisticated HF .In the case of beating two independent laser lines5 the poor linewidth characteristic of the beat note is a major drawback. In this work we report on large amplitude continuously tunable oscillations with very low phase noise obtained by injecting CW light from a master laser into an unmodulated slave laser detuned to frequencies outside the optical locking range. Due to the interaction of the two optical fields in the slave laser cavity we call this technique ' Injection Tracking '.