Sign conventions in magneto-optical calculations and measurements.

A brief outline is given of the multiplicity of sign conventions appearing in the literature in association with theoretical and experimental topics concerning magneto-optics. It is shown that there are essentially two competing schemes available for the description of magneto-optical effects and that these are not, in all respects, entirely equivalent. A summary of these sign conventions is presented, and reasons are given for the adoption of a particular preferred scheme.

Reflection filter multilayers of metallic and dielectric thin films.

Narrowband spectral filters operating in reflection and consisting of multilayers containing both dielectric and metallic films are of interest for fiber-optical communication systems at wavelengths from 1250 to 1600 nm. Formulas are derived which relate the potential transmittances of the main metallic film to important specifications of the filter, namely, bandwidth and rejection, and it is shown how the parameters of the layers are chosen to meet these and other requirements such as free spectral range. Monitoring procedures are discussed, and the results of photometric observations on five filters are compared to theoretical predictions.

Optical properties of narrow-band spectral filter coatings related to layer structure and preparation.

The optical properties of thirty-five all-dielectric spectral filter coatings for the visible spectrum have been investigated and correlated with the deposition conditions of the constituent layers of cryolite and zinc sulfide and with the processes which occur when the coatings are exposed to atmosphere. It will be shown that the results of measurements of transmittance and reflectance over the passband wavelengths can be predicted theoretically only if account is taken of absorption in the layers and scattering at the rough boundaries and of changes in the refractive indices of the layers due to water penetration.

Thin films of manganese bismuth for erasably recording laserbeam irradiance distributions.

Examples are given of the application of a thin film of manganese bismuth to recording the irradiance distributions in high-power laser beams of the type used in plasma and fusion research. The erasable nature and high resolution of the record and the facility for contrast reversal are emphasized, as is the nonlinear relationship between irradiance of the laser beam and the magneto-optical contrast. Important physical parameters of the recording medium are tabulated.