Yu.S. Stirmanov − Post-graduate Student, 

Kotel’nikov Institute of Radioengineering ang Electronics of RAS (Moscow) 

I.V. Grishchenko − Student, 

Moscow Institute of Physics and Technology (MIPT)

E-mail: ivan.grishchenko@phystech.edu,

A.V. Konyashkin – Ph.D. (Phys.-Math.), Senior Research Scientist,

Fryazino branch of Kotel’nikov Institute of Radioengineering ang Electronics of RAS 

O.A. Ryabushkin – Ph.D. (Phys.-Math.), Associate Professor, Head of the Laboratory,

Fryazino branch of Kotel’nikov Institute of Radioengineering ang Electronics of RAS  E-mail: roa228@mail.ru

Problem formulating. Efficiency of laser radiation frequency conversion in nonlinear-optical crystals depends on its temperature. In the case of high-intensity radiation even low absorption can result in significant heating, violation of phase-matching conditions and optical damage.

Goal. Approbation of the piezoelectric resonance laser calorimetry (PRLC) for measurements of optical absorption and heat exchange coefficients of lithium triborate (LBO) crystals interacting with high-intensity laser radiation at 1070 nm wavelength. Result. Values of optical absorption α=(2.9±0.7)·10–4 cm–1and heat exchange hT=(33±6) W/(m2ºС) coefficients of LBO measured using PRLC remain constant in 10 MW/cm2 – 100 MW/cm2 intensity range.

Practical meaning. It was demonstrated that the PRLC technique can be used for measurements of optical absorption and heat exchange coefficients of nonlinear-optical crystals interacting with high-intensity laser radiation.

1. Nikogosyan D.N. Nonlinear optical crystals: a complete survey. New York: Springer Science & Business Media, 2006.
2. Avdokhin A., et al. High average power quasi-CW single-mode green and UV fiber lasers. Nonlinear Frequency Generation  and Conversion: Materials, Devices, and Applications XIV. – International Society for Optics and Photonics. 2015. V. 9347.  P. 934704.
3. ISO 11551: Test Method for Absorptance of Optical Laser Components, Int. Organization for Standardization, Genewa, Switzerland, 2007.
4. Ryabushkin O.A., et al. Equivalent temperature of nonlinear-optical crystals interacting with laser radiation. Journal of the European Optical Society − Rapid publications. 2011. V. 6. P. 11032.