0.53 bit/s/Hz spectral efficiency free-space demultiplexer with very low crosstalk, loss and polarisation dependence

Abstract

The authors describe the performance of a diffraction grating demultiplexer for narrow channel spacing of 0.15 to 0.40 nm, operating over a 50 nm spectral range. The device exhibited a fibre-to-fibre loss of 3.8 dB, polarisation dependence of < 0.3 dB, and background crosstalk of –60 dB. A spectral efficiency of 0.53 bit/s/Hz for NRZ transmission of 11 × 10 Gbit/s modulated channels spaced by 0.15 nm (18.8 GHz) is reported.