High spectral purity millimetre-wave modulated optical signal generation using fibre grating lasers

Millimetre-wave optical signal generation by heterodyning two semiconductor fibre grating lasers is demonstrated for the first time. The resulting beat signal, has an extremely narrow linewidth (<100 kHz), is continuously tuneable (0-40 GHz) and exhibits negligible chirp under direct 2.6 Gbit/s modulation.