Quantum calculation of the performance of traveling wave semiconductor laser amplifiers for simultaneous amplification and detection

The noise properties of semiconductor laser amplifiers were calculated using the Heisenberg equations of motion. Photon noise as well as the recombination current noise were calculated with this formalism. The formalism also gave the conventional current shot noise in the appropriate limits, e.g., when using the amplifier reverse-biased as a detector. The results of the proposed method are in reasonable agreement with reported experimental results, and the current noise could be given a consistent physical explanation. The quantum analysis of the noise in a semiconductor laser amplifier used as a detector shows that its sensitivity should be roughly comparable to that of a PIN FET receiver.