Nibu, A George; Dr. Radhakrishnan, P(Cochin University of Science and Technology, May 14, 2001)
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Abstract:
The emergence of lasers in the early sixties has not only revolutionized the field of optics
and communication but also paved new ways in the field of material characterization. Material studies using photothermal techniques possess certain unique characteristics and advantages over conventional methods. The most important aspect of photothennal techniques is their ability to perform noncontact and nondestructive measurement. Photoacoustics, photothermal deflection, thermal lens, photothermal radiometry and photopyroelectric methods are some of the commonly used and powerful techniques for the thermal and optical characterization of materials using lasers.
In this thesis the applications of photoacoustic and photothermal deflection techniques
for the thermal and optical characterization of different photonic materials, namely,
semiconductors, liquid crystals and dye-doped polymers are discussed
Description:
International
School of Photonics, Cochin University of Science and Technology
Nampoori, V P N; Vallabhan, C P G; George, A K; Radhakrishnan, P; Rajasree, K; Vidyalal, V(Elsevier, July , 1998)
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Abstract:
he phenomenon of single beam mirage effect, otherwise known as photothermal deflection (PTD) effect using a He–Ne laser beam has been employed to detect phase transitions in some liquid crystals. It has been observed that anomalous changes in amplitude occur in the PTD signal level near the transition temperature. The experimental details and the results of measurements made in liquid crystals E8, M21 and M24 are given in this paper.