A 10-fs Multicolor Source for Ultrafast Spectroscopy and Quantum Communication
Broadband multicolor lasers are able to provide valuable information concerning ultrafast molecular dynamics through time-resolved spectroscopy. Here, I present my work developing a multicolor, 10-fs laser source through the marriage of three key technologies: (1) a high-repetition-rate, 10-fs, energetic NIR front end, (2) NIR pulse shaping, and (3) adiabatic frequency conversion. These technologies provide the means to generate femtosecond pulses in the visible, near-IR, and mid-IR with amplitude and phase control without multiple com plex dispersion-management schemes, constituting a toolbox of femtosecond pulses that can be used to probe fleeting molecular dynamics. 100-µJ, 10-fs pulses are generated from the NIR front end, which are shaped and compressed with NIR 4f pulse shapers and subsequently converted to 10-fs visible (MIR) pulse using dispersion-managed adiabatic sum (difference) frequency generation. Compression of the NIR pulses has been confirmed using SHG FROG. The MIR pulses were measured using a sensitive, phase-matching-free technique called frequency-resolved optical switching. Additionally, various ap plications are reviewed including quantum frequency homogenization, simultaneously converting visible single photons to the telecom C-band and reducing their spectral distinguishability, and ultrafast time-resolved spectroscopy experiments planned for single-layer graphene, rhodopsin and various mutants, and DNA.