Abstract
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.
Publisher
Belarusian State University
Reference17 articles.
1. Artemiev NM, Batishche SA, Bortkevich AV, Eremenko AS, Malinin BG, Mostovnikov VA, et al. [Highly efficient microsecond dye solution laser converter]. Zhurnal prikladnoi spektroskopii. 1987;47(5):719–723. Russian.
2. Batishche SA, Mostovnikov VA, Tarkovsky VV. [Wide-range microsecond dye laser with two-stage excitation]. Kvantovaya elektronika. 1995;22(7):651–652. Russian.
3. Batishche SA, Mostovnikov VA, Tarkovsky VV. [Investigation of amplifying circuits of microsecond dye lasers with two-stage excitation]. Pribory i tekhnika eksperimenta. 1995;4:130–137. Russian.
4. Batishche SA, Ganzha VA, Mostovnikov VA, Malevich NA, Perlov DI, Shifrin VP. [Investigation of the operation of a laser system based on dye solutions pumped by nanosecond high-power radiation pulses]. Zhurnal prikladnoi spektroskopii. 1983;39(6):934–938. Russian.
5. Tarkovsky VV, Kurstak VYu, Anufrik SS. [Dependence of the generation efficiency on the excitation frequency during pumping of a solution of rhodamine 6G by microsecond laser pulses]. Zhurnal prikladnoi spektroskopii. 2002;69(6):747–750. Russian.