Highly Efficient Wavelength-Tunable Anti-Stokes Signal Conversion of Femtosecond Pulses in the Fundamental Mode of Photonic Crystal Fiber

摘要

With the photonic crystal fiber (PCF) with the zero dispersion wavelength of fundamental mode around 830 nm designed and fabricated in our lab, the anti-Stokes signals from 603 to 535 nm are efficiently generated in the fundamental mode by Ti:sapphire laser with central wavelength of 820 nm and pulse width of 150 fs. When the pump power increases from 80 to 320$~$ mW in a separation of 40 mW, the output powers of anti-Stokes signals increase 6 times, and the maximum power ratio of anti-Stokes signal at 535 $~$nm to the residual pump component is estimated as 12:1. The maximum output power ratio of the anti-Stokes signal at 535 nm and the Stokes component at 865$~$nm is about 2:1. The maximum conversion efficiency of $P_{rm a}/P_{{rm p}0}$ in experiment can achieve up to 42%, and the possible reasons for discrepancy between experimental and theoretical results are analyzed. Moreover, the influences of other factors on experiment process are elementarily discussed.