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The first known totally noncontact optoacoustic measurement in a flame, using a pulsed laser to excite an acoustic pulse and observing the transient deflections of cw probe beams to detect the acoustic propagation, is described. All laser beams are coplanar, parallel, suitably displaced, and focused inside the flame. Such laser-based ultrasonic measurements provide a new way to map out temperature and flow profiles in flames or other hostile environments.

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The thickness and the dielectric constants of thin metal films on glass substrates are determined by two different methods. The first method is a combination of transmission and ellipsometer measurements (TELL method) and the second is based on attenuated total reflection (ATR method in the Kretschmann arrangement). For comparison, both methods are applied to gold films within a thickness range of 20-80 nm. Furthermore, the TELL method was applied to chromium films of thicknesses up to 150 nm. All experiments are done with a He-Ne laser at 633-nm wavelength.