RESUMO
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.
RESUMO
A current-tuned GaAlAs-diode laser is utilized both to burn and to detect narrow photochemical holes in the inhomogeneously broadened 833-nm zero-phonon line of the R' color center in LiF. Applications for reading and writing data into frequency-domain optical memories based on photochemical hole burning are discussed.
RESUMO
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.
RESUMO
The absorption coefficient of SO(2) under atmospheric conditions was measured at twenty DF laser lines. Weak absorption (alpha* less, similar 0.003 cm(-1) atm(-1)) was found for a few wavelengths around 3.7 microm. Only the P(4)(6) line at 3.9843 microm (nu = 2509.86 cm(-1)) is strongly absorbed [alpha* =(0.44 +/- 0.01) cm(-1) atm(-1)]. The pressure dependence of the P(4)(6) cross section was measured. Self-broadening and foreign-gas broadening coefficients are between 1.5 and 5 MHz/Torr, and the distance from the P(4)(6) DF line to the center of the nearest SO(2) line is (0.0043 +/- 0.0004) cm(-1).
