A study on novel spectral behaviors of ultrabroad-band optical pulses generated by induced-phase modulation in a gas-filled hollow fiber using a modified SPIDER technique

Summary form only given. In order to generate monocycle optical pulses, we proposed a technique of utilizing not only self-phase modulation (SPM) but also induced-phase modulation (IPM) in an optical fiber. With respect to compression of optical pulses generated in a fiber, recently we have compensated for chirp of induced phase-modulated pulses. However, fused-silica fibers are not suitable to generate optical pulses which have higher energy (>100 nJ) because of optical breakdown. To overcome the problem, we use a gas-filled hollow fiber as a nonlinear device. We let a femtosecond fundamental beam (center wavelength 790 nm; pulse energy 110 /spl mu/J; pulse width 30 fs; repetition rate 1 kHz) and its second harmonic beam (center wavelength 395 nm; pulse energy 13 /spl mu/J; pulse width 30 fs) copropagate in a hollow fiber filled with 2.0-atm argon gas, and generated ultrabroad-band optical pulses by SPM and IPM in the fiber. Output chirp was compensated for tentatively by a 4-f pulse shaper with a spatial light modulator.