The impact of in-band crosstalk on the transmission performance of optical cross-connects, incorporating (de)multiplexers and space switches, is studied. A statistical description of the receiver decision variable that yields a performance analysis in good agreement with experiment is given. Bit error rate and power penalties are calculated using the so-called saddlepoint approximation which is numerically simple and gives accurate results.
Idelfonso Tafur Monroy and Eduward Tangdiongga, "Performance Evaluation of Optical Cross-Connects by Saddlepoint Approximation," J. Lightwave Technol. 16, 317- (1998)