Abstract: A laser gyroscope is formed as a sealed, unitary assembly of mirrors optically contacted to a monolithic gyro block without any means, such as Brewster windows, for isolating the laser plasma from any of the mirrors. The mirrors are fabricated with hard multilayer dielectric films which can withstand plasma exposure. A magnetic mirror utilizing the transverse Kerr effect to separate the frequencies of counter-propagating beams, and to avoid lock-in, includes a Ni-Fe alloy layer over which is directly deposited a thin iron or iron alloy layer to form a rotationally switchable Kerr effect combination. The magnetic field for switching is generated by an electric current developed in two pairs of orthogonally disposed wires embedded in the substrate immediately below the iron and Ni-Fe alloy layers.

Abstract: A laser or other light beam is directed onto an optical substrate while an optical coating is being vacuum deposited thereon. The laser has a wavelength at or near that at which a reduced absorptance of the coating is desired. In one embodiment, the substrate is heated electrically. Thin film optical coatings having a substantially lowered absorptance are made in this manner.