Noiseless independent signal and power amplification

Opt Lett. 1998 Apr 1;23(7):540-2. doi: 10.1364/ol.23.000540.

Abstract

We present a noiseless optical amplifier comprising a signal-amplifying feed-forward loop and a power-amplifying injection-locked laser. We demonstrate that the signal amplifier can attain a signal-transfer coefficient limited solely by the quantum efficiency of our in-loop photodetector and that we can independently amplify the optical power while leaving the normalized intensity-noise spectral density of the input field unchanged.