Surface polish characterization of industrial Ti: sapphire laser crystal rods by photopyroelectric scanning imaging

Measurement of thermal diffusivity of air using photopyroelectric interferometry

“…Photothermal and photoacoustic techniques have been used successfully in studies of optical and thermophysical properties of solids as nondestructive evaluation methodologies. [1][2][3][4][5] Recent developments in monitoring and measuring the properties of gases using photothermal techniques have attracted much attention for environmental quality control and manufacturing safety reasons. [6][7][8][9] Specifically, a newly developed 8 thermal-wave resonant cavity ͑TWRC͒ sensor using a pyroelectric thin-film transducer ͑polyvinylidene fluoride, PVDF͒ proved to offer a powerful method for measuring the thermal diffusivities of gases with very high precision and gas-species resolution.…”

Deconvolution and measurement of bulk and surface optical absorptions in Ti:Al2O3 crystals using photopyroelectric interferometry

“…Photothermal ͑PT͒ and photoacoustic ͑PA͒ spectroscopic techniques have been used successfully in measurements of optical absorption coefficients and nonradiative quantum efficiencies for a variety of optical materials, including laser crystals. [1][2][3][4][5][6][7][8][9][10][11][12][13] Among the various embodiments of PA and PT techniques, photopyroelectric detection ͑PPE͒, as pointed out elsewhere, [1][2][3][4][10][11][12]14 has a certain number of advantages. A major advantage of PPE detection over other conventional PT techniques is the fact that one can measure directly and self-consistently both the optical absorption coefficient, ␤͑͒, and the nonradiative quantum efficiency, ͑͒.…”

“…The contributions from the surface and the bulk were thus separated from each other. It was shown, 3,11,12 however, that the sensitivity of conventional single-ended PPE measurements suffers from a large baseline signal, generated by the direct transmission to the detector surface of the incident radiation through the transparent sample under investigation. With regard to transparent materials, this large baseline signal, which appears in the lock-in IP channel, is much larger than that of the Q channel, by more than two orders of magnitude.…”