Tunable double-channel ultrashort-pulse optical oscillator

An apparatus was made for selective two-stage electronic excitation of complex organic molecules in solution. Radiation from a mode-locked Nd:YAG laser was frequency-converted by the parametric superradiance effect. A wavelength tuning rang of 0.26–4 μ, a wavelength-dependent pulse energy of 1 μJ to 1 mJ, and a pulse repetition frequency of 0.5 Hz were obtained.