2015: Essential reduction of generation thresholds in inhomogeneously diode-end-pumped lasers
MSU physicists (Prof. Vladimir Tunkin, Dept. of General Physics and Wave Processes) in collaboration with researchers from Lebedev Physical Inst. of the RAS experimentally demonstrated a substantial drop in the generation threshold of inhomogeneously diode-end-pumped lasers in degenerate resonator configurations.
Experimentally demonstrated that degenerate configurations of laser resonator can substantially influence not only the output radiation profile but also the laser threshold in the case of some resonator inhomogeneity. This inhomogeneity cause the transfer of the field from one Laguerre-Gaussian mode to another and in this way to the synchronization of their phases in degenerate resonator configurations where mode frequencies are equal. Therefore a narrow radiation peak is formed on the surface of the mirror close to the active crystal. The peak diameter is close to the pump beam diameter, this leads to the drop of the generation threshold in 2.5-3 times in some degenerate configurations.
The results of this work were published in the paper: Bezotosnyi V., Cheshev E., Gorbunkov M., Koromyslov A., Kostryukov P., Krivonos M., Popov Yu., Tunkin V., “Behavior of threshold pump power of diode end-pumped solid-state laser in critical cavity configurations”, Laser Physics Letters 12, 025001 (2015).