Compression of optical pulses spectrally broadened by self-phase modulation with a fiber Bragg grating in transmission

We demonstrate experimentally the compression of optical pulses, spectrally broadened by self-phase modulation occurring in the rod of a mode-locked Q-switched YLF laser, with an unchirped, apodized fiber Bragg grating in transmission. The compression is due to the strong dispersion of the Bragg grating at frequencies close to the edge of the photonic bandgap, in the passband, where the transmission is high. With the systems investigated, an 80-ps pulse, which is spectrally broadened, owing to self-phase modulation, with a peak nonlinear phase shift of Delta Phi = 7, is compressed to approximately 15 ps, in good agreement with theory and numerical simulations. The results demonstrate that photonic bandgap structures are promising devices for efficient pulse compression. (C) 1998 Optical Society of America.