Sensitivity improved photonic Instantaneous Frequency Measurement receiver

A simple technique to improve the sensitivity of a photonic instantaneous frequency measurement receiver using low-cost, low-frequency photo-detectors is proposed and practically demonstrated. The introduction of the lock-in amplification allows RF input power can be reduced by 16 dB when compared to the un-locked system while still maintaining sensitivity. Formal quantification of the noise floor of the system and extension to GHz frequencies is currently under investigation.