Developments of widely tunable light sources for picosecond time-resolved resonance Raman spectroscopy

Abstract

Two systems of widely tunable light sources for picosecond time-resolved resonance Raman (ps-TR3) spectroscopy have been constructed using a 1 kHz ps-Ti:sapphire laser/regenerative amplifier system. Performance of the systems was examined in terms of pulse duration, spectral width, pulse energy, and shot-to-shot stability. One system, consisting of white light continuum seeder and β-barium borate optical parametric amplifier, demonstrated tunability in the 500–660 nm range with 1.3–2.1 ps pulse duration and 15 μJ pulse energy. The other system, consisting of a lithium triborate optical parametric generator in type II noncritical phase matching configuration and β-barium borate optical parametric amplifier, was found to yield visible pulses as high as 18 μJ with 1.5–2.4 ps of pulse duration in the 520–630 nm region. The shot-to-shot stability of generated pulses is less than 10% for both systems. Capability of the present systems is demonstrated by observing ps-TR3 spectra of nickel octaethylporphyrin in coordinating and noncoordinating solvents.