Precise measurements of the low optical absorption coefficients of massive lithium triborate crystal boules with untreated facets formed during the growth process.

A spatial diagnostic of optical quality of the massive lithium triborate crystal boule with untreated facets was performed by measuring optical absorption coefficients at 1070 and 1908 nm wavelengths using the piezoelectric resonance laser calorimetry technique.

Acoustic resonance laser calorimetry for measurements of low optical absorption.

A novel method of acoustic resonance laser calorimetry (ARLC) for the determination of low optical absorption coefficients of crystals and glasses is introduced. It is based on measurements of the kinetics of the equivalent temperature of the sample irradiated by the pulse laser radiation. The equivalent temperature of the sample is directly obtained by measuring the frequency changes of its temperature-calibrated acoustic resonances excited by the laser radiation with a corresponding pulse repetition rate.

Accurate measurements of longitudinal temperature distribution of PPLN crystal in the process of second-harmonic generation.

Phase-matching temperature tuning curves and longitudinal temperature distribution of periodically poled lithium niobate (PPLN) crystal were measured in the process of second-harmonic generation (SHG) of 1070 nm pump wavelength using tiny transparent piezoelectric crystals as the temperature sensors. The temperatures of the crystal sensors placed along the PPLN length were determined directly by measuring the induced frequency shifts of their piezoelectric resonances, which were excited in a noncontact manner by a probe radio-frequency electric field. Such temperature sensors do not suffer additional heating conditioned by absorption of scattered radiation and also do not have any contact wires.

Anisotropy of nonlinear optical absorption of LBO crystals at 355 nm.

The dependence of the nonlinear optical absorption coefficients on the intensity and polarization of pulsed laser radiation at 355 nm was investigated for lithium triborate (LBO) crystals using the piezoelectric resonance laser calorimetry.