A Super-Continuum Based All Optical Multi-Channel Source Generation in Radio-on-Fiber System

A millimeter-wave-band multi-channel source generating method for wavelength-division-multiplexed(WDM) radio-on-fiber(ROF) systems is proposed.Firstly,the combined use of a femto-second semiconductor mode-locked laser and two 5m-long high nonlinear photonic crystal fibers with opposite dispersion values is demonstrated experimentally to implement a super-continuum with width of more than 170 nm around 1 550 nm.Secondly,a sampled fiber Bragg grating is used to filter spectrum.It is shown that the spectrum is sliced into 20 channels with ±0.3 dB peak fluctuation.Each two adjacent channels can be filtered out as one channel radio-frequency carrier.10-channel carriers are successfully obtained for WDM-ROF system.These ten-channel carriers have some advantages such as small gain fluctuation,large modulation depth and narrow width,etc..Besides,the whole system can be easily integrated for its simple structure and small insertion loss.