Coherent detection RF-IF down converting link using injection locked laser design

Abstract

A coherent detection RF-IF down converting link utilizing injection-locked distributed feedback (DFB) lasers is demonstrated. This photonic link design provides several RF performance advantages. Coherent detection allows unambiguous recovery of full time-domain I/Q IF signals. Injection locked laser design relaxes the tuning range requirement on RF local oscillators, and provides high optical power for efficient RF-IF conversion while minimizing degradation to link sensitivity due to phase noise. A cascaded injection locked configuration suppresses LO related spurious tones in the IF band is also demonstrated. Sensitivity and dynamic range data from RF C-band to Ka-band are presented.