Nonlinear thermally induced distortions of a laser beam in a cryogenic disk amplifier

Journal Article · Wed Sep 30 00:00:00 EDT 2009 · Quantum Electronics (Woodbury, N.Y.)

DOI:https://doi.org/10.1070/QE2009V039N09ABEH014039· OSTI ID:21471094

Vyatkin, A G; Khazanov, Efim A ^[1]

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1. Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)

Taking into account the temperature dependences of the heat conductivity, the refractive index, and the thermal expansion coefficient, we calculated the temperature, elastic stresses, a thermally induced lens and depolarisation of a beam in a cryogenic disk amplifier (an Yb:YAG disk placed between a copper cylinder and a sapphire disk cooled by liquid nitrogen). When the active element (the thickness is 0.6 mm, the orientation is [001], the atomic concentration of Yb is 10%) is pumped by radiation from a diode laser (the beam diameter is 6 mm), the temperature does not exceed 140 K for the heat release power of 100 W. In this case, elastic stresses in the active element are six times lower than the maximum permissible value. The focal distance of the thermally induced lens is 5.5 m and the depolarisation rate is 0.038% per two passes through the active element. Although the heat conductivity of the active element rapidly decreases with temperature, the thermal load can be increased by 1.5-2 times when the dimensions of the active element remain constant. (active media)

• OSTI ID: 21471094
• Journal Information: Quantum Electronics (Woodbury, N.Y.), Vol. 39, Issue 9; Other Information: DOI: 10.1070/QE2009v039n09ABEH014039; ISSN 1063-7818
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AMPLIFIERS
COPPER
CRYSTAL STRUCTURE
DEPOLARIZATION
NEODYMIUM LASERS
NITROGEN
NONLINEAR PROBLEMS
POLARIZED BEAMS
REFRACTIVE INDEX
SAPPHIRE
TEMPERATURE DEPENDENCE
THERMAL CONDUCTIVITY
THERMAL EXPANSION
THERMAL STRESSES
BEAMS
CORUNDUM
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
EXPANSION
LASERS
METALS
MINERALS
NONMETALS
OPTICAL PROPERTIES
OXIDE MINERALS
PHYSICAL PROPERTIES
SOLID STATE LASERS
STRESSES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS