The generation efficiency of a number of ethanol dye solutions is studied as a function of the coherent microsecond pump wavelength. It is shown that the maximum lasing efficiency is achieved by pumping not to the maximum of the main band of the absorption spectrum of dyes. In the spectral ranges determined for each dye, a decrease in the generation efficiency is observed. The reasons for this phenomenon – triplet-triplet and singlet-singlet absorption – are analised. The main role in the case under consideration is played by the absorption of pump radiation in the system of excited singlet levels with the formation of long- and short-lived photoproducts that absorb in the amplification region but do not participate in generation. A study of the luminescence kinetics of the DCM dye showed that another reason for the appearance of induced losses is the non-linear scattering of radiation in a dye solution, which occurs because of non-stationary self-diffraction of pump radiation on phase noise gratings formed as a result of heat release when light is absorbed in the channel of excited singlet levels in a bleaching dye solution. Experiments on probing induced losses, as well as picosecond spectroscopy, confirmed the appearance of thermooptical distortions of the active medium in certain spectral intervals of microsecond coherent pumping.

Influence on the generating losses on the spectral efficiency of ethanol solutions of dyes of various classes

This paper examines the basic questions which must be taken into account in the development of powerful dye lasers, pumped by nanosecond pulses, suitable for use in wide-range laser systems with highly efficient nonlinear frequency converter for the example of the development of a dye laser pumped by a single-pulse ruby laser. The optical layout of the dye laser pumped by a single-pulse ruby laser is shown. It is shown that the energy efficiency of the operation of dye amplifiers depends substantially both on the power density of the amplified signal and on the power density of the radiation. The use of a radiation frequency converter based on stimulated Raman scattering in compressed hydrogen at the output of the laser system developed enabled covering the spectral range 1.1-8.11 mm with powerful laser radiation.

V. I. Gurlenya

Papers

Basic problems in the development of powerful wide-range laser systems based on solutions of dyes