High-quality sub-100-fs optical pulse generation by fiber-optic soliton compression of gain-switched distributed-feedback laser-diode pulses in conjunction with nonlinear optical fiber loops.
We report our investigations of a new and simpler femtosecond fiber-optic soliton compressor for chirp-compensated gain-switched diode-laser pulses and of pedestal suppression by a compound fiber loop mirror (CFLM) and nonlinear-optical loop mirrors (NOLM's), both of which are designed for sub-100-fs pulse generation of high quality. The soliton compressor, composed of a 21.1-m-long steplike dispersion profiled fiber, exhibited 44-fs pulses and a compression ratio of approximately 60. Pedestals of 100-fs soliton pulses were suppressed successfully (>20 dB) by the CFLM and the NOLM's. In particular, 63-fs pedestal-free sech(2) pulses were obtained by NOLM propagation.