Weak RF signals detection based on all-optical multi-mode oscillation with high performance

What we believe to be a novel photonic-assisted system for radio frequency (RF) signal detection with high gain, high sensitivity and broad frequency range based on all-optical multi-mode oscillation (OMMO) has been proposed and experimentally demonstrated. Differing from multi-mode optoelectronic oscillation systems, the active devices in the oscillation loop are limited to a single EDFA and an optical modulator. This design eliminates the need for additional lasers, electrical amplifiers, and electrical/optical filters, resulting in a simple structure with very low cost and great performance. The system provides an average gain over 27 dB for RF signals and the sensitivity is as low as -97 dBm. Benefiting from the mode coupling effect in the dual loops with almost equal length, the detection range can be greatly improved to hundreds of GHz in theory, breaking through the bandwidth limitation of filters.