We present an analysis of quantum-limited DPSK receivers with optical Mach-Zehnder interferometer (MZI) demodulation. It is shown for the first time that the quantum limits for DPSK/MZI receivers with single-port and balanced detections exactly differ from 3-dB in receiver sensitivity, obtained by both Poisson and Gaussian noise statistics.
Cite
@article{arxiv.physics/0410077,
title = {Quantum Limited DPSK Receivers with Optical Mach-Zehnder Interferometer Demodulation},
author = {Xiupu Zhang and Guodong Zhang},
journal= {arXiv preprint arXiv:physics/0410077},
year = {2007}
}