Photon statistics of amplified spontaneous emission noise in a 10 Gb/s optically pre-amplified lightwave direct detection receiver

The determination of receiver sensitivity and bit-error rate (BER) is important in the design of high bit rate optical digital communication systems at the 1.5 μm wavelength, where the most sensitive receivers use optical preamplification. There exists two classes of models for the analysis of optically amplified signals. The first class uses the semiclassical square-law model for detection, resulting in a Gaussian distribution for the photocurrent. The second class uses quantum mechanics to treat spontaneous and stimulated processes in the optical amplifier. The advantages of the semiclassical models are simplicity and the fact that it yields an analytical expression for the BER, while the advantage of the quantum mechanical model is its correctness in describing the physical processes. In this paper, we show that the photon distribution of the zeros obtained experimentally is indeed Bose-Einstein distributed. We then demonstrate that we can predict the sensitivity of the receiver based on the quantum mechanical model