A method for deriving optical constants from reflectance vs angle of incidence measurements using a nonlinear least-squares curve-fitting technique based on the chi(2) test of fit is presented and used to derive optical constants for several thin-film materials. The curve-fitting technique incorporates independently measured values for the film surface roughness, film thickness, and incident beam polarization. The technique also provides a direct method for estimating probable errors in the derived optical constants. Data are presented from 24 A to 1216 A for thin-film samples of C, synthetic diamond, Al, Si, and CVD SiC. Auger electron spectroscopy depth profiling measurements were performed on some of the samples to characterize sample composition including oxidation and contamination.

The laser-induced damage thresholds of two different dielectric thin-film coatings increased with decreasing spot size and were invariant for spot sizes greater than 150 μm. A simple model has been suggested that the distribution and nature of coating defects have played an important role in this spot-size dependence, e.g., the probability of the laser beam striking a defect site will be greater for larger spot sizes and that damage in materials can be distinguished as defect damage and intrinsic damage.

Abshact-YB~Cu30x (YBCO) films have been deposited on buffered metal substrates by metal organic chemical-vapor deposition (MOCVD). Nickel alloy substrates with biaxirdlytextured yttria-stabilized zirconia (YSZ) buffer layers deposited by ion-beam-assisted deposition (IBAD) were used. A liquidstatic precursor delivery system was designed, constructed, and used in the MOCVD facility at Intermagnetics for the reported work. At 77 & under self-field conditions, we achieved a critical current (Q of 97.5 A in YBCO film grown by MOCVD on an IBAD substrate. This ICcorresponds to a critical current density of 1.3 MA/cm2 and 130 A/cm width of tape.

Reflectance vs incidence angle measurements have been performed from 24 A to 1216 A on electron-beam evaporated samples of Ti, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, Ir, Pt, and Au, and using a nonlinear least-squares curve-fitting technique, the optical constants have been determined. Independently measured values of the incident beam polarization, film thicknesses, and film surface roughnesses are incorporated into the derivation of the optical constants. Additionally, Auger electron spectroscopy depth profiling measurements have been performed on each sample to characterize sample composition including oxidation and contamination.