Soliton Self-Frequency Shift in a Short Tapered Air-Silica Microstructure Fiber
15 March 2001
We report soliton self-frequency shift of over 20% of the optical frequency in a tapered air-silica microstructure fiber that exhibits a widely flattened large anomalous dispersion in the near infrared. Remarkably the large frequency shift was realized in a fiber of length as short as 15 cm, two orders of magnitudes shorter than those reported previously with similar input pulse duration and pulse energies, owing to the significantly enhanced nonlinear effects in the tapered fiber and its unique dispersion characteristics. By varying the power of the input pulses, compressed sub-100- fs soliton pulses of ~1 nJ pulse energy tunable from 1.3microns to 1.65microns were generated with over 60% conversion efficiency.