Photonic Crystal Fiber Based Wavelength-Tunable Optical Parametric Amplifier and Picosecond Pulse Generation

We report a fiber optical parametric amplifier (FOPA) based on a photonic crystal fiber (PCF) with optimized dispersion and nonlinear properties pumped by a mode-locked ytterbium-doped fiber laser. Wavelength-tunable parametric gain bands can be obtained by adjusting the pump wavelength from the anomalous to the normal dispersion regime. By utilizing the PCF-based FOPA, weak signals located in the parametric gain bands can be amplified. Wavelength-tunable picosecond pulses can be generated at the signal and idler wavelengths. A 58-dB maximum gain and a wide gain bandwidth from 999 to 1139 nm have been achieved by pumping near the zero-dispersion wavelength. When the FOPA is pumped at 1062.5 nm in the normal dispersion regime of the PCF, the 974-nm weak continuous-wave signal is significantly amplified, and the idler pulse is generated at 1168 nm.