Generation of anti-stokes line in fundamental mode of photonic crystal fibre

A photonic crystal fibre (PCF) with zero-dispersion wavelength around 800 nm is designed and fabricated. Simulated results show that the zero-dispersion wavelength of fundamental mode for this PCF is at 826 nm, and phase-matched four-wave mixing can be achieved in fundamental mode. Using 200fs Ti:sapphire laser with central wavelength at 810 nm as pump, the anti-Stokes line around 610 nm is generated efficiently. The output signal has a Gaussian-like profile, which indicates that the anti-Stokes signal is in the fundamental mode of the PCF. The energy of anti-Stokes signal is higher than that of residual pump laser and the maximum ratio of the anti-Stokes signal to the pump component in the output spectrum is estimated to be 1.2.