Characteristics of picosecond emission from a distributed-feedback laser with a binary mixture of dyes under nanosecond excitation

An investigation was made of the generation of picosecond pulses in a distributed-feedback (DFB) laser with a binary mixture of dyes excited by nanosecond pulses. In contrast to a one-component solution, the duration and energy of the output pulses emitted by the binary mixture decreased at the short-wavelength edge of the tuning range, which was due to the absorption of the laser radiation by acceptor molecules. An investigation of the polarisation and kinetics of the radiation emitted by the DFB laser showed that the radiative and nonradiative transfer of the excitation energy in the binary dye mixture had different effects on the generation of picosecond pulses, which led to the appearance of two independent trains of ultrashort light pulses or of single pulses.