Optical crosstalk predictions for LED based analogue WDM systems

An analytical framework is advanced for the prediction of linear optical crosstalk levels in LED based wavelength division multiplexed (WDM) systems by assuming both the spectral emission from LED devices and the transmission of optical filtering elements as being Gaussian distributed. Mathematical expressions are provided which allow calculation of crosstalk levels for systems having wavelength channels addressed by using separate LED sources and those extracted by using spectral slicing techniques. These expressions enable the design of a WDM system optimised for spectral bandwidths λ_w and wavelength separations Δ between the channels for any desired crosstalk level C. These quantities are found to be related through the expression C≃-6(Δ/λ_w)² which can be used either to assess or predict the potential crosstalk performance of a WDM system