Tunable Optoelectronic Oscillator based on an integrated heterodyne source
Abstract
We demonstrate an optoelectronic oscillator (OEO) tunable from 15 to 20 GHz in which the optically carried microwave signal is generated by two distributed feedback (DFB) lasers on the same InP chip. Tunability is obtained by adjusting, thanks to the two bias currents, the optical frequency separation between the DFB laser tones. Phase noise reduction is obtained by combining optical self-injection locking inside the chip and a fiber delay-line coupled to a modulation section integrated on the chip.