A tunable dual-polarization liquid-crystal etalon filter, in which a Fabry-Perot cavity is set up between two end reflectors, preferably interference mirrors. A nematic liquid crystal fills a substantial portion of the Fabry-Perot cavity. The alignment layer adjacent to one end of the cavity is dividend into two portions, both of which are homogeneous but which are buffed in orthogonal directions so that they align the liquid crystal parallel to their surfaces but at orthogonal directions to eac...

An all-optical swtich apparatus having an optical gate which is unitarily composed of a nonlinear etalon and a pair of GRIN lenses, or a nonlinear etalon and a GRIN lens, and having collimating GRIN lenses, each of which guides a signal beam and a control beam to the optical gate. The resonance wavelength of the etalon can be regulated by adjusting the incident positions of signal beam and/or control beam to the optical gate by moving the collimating GRIN lenses. This decreases the required thic...

An actively stabilized laser is disclosed which includes a temperature tunable etalon in the laser cavity for single frequency operation. The operation of the laser is actively monitored to detect variations induced by changes in the length of the resonator. These changes tend to cause the frequency of the selected longitudinal mode to shift so that it is no longer aligned with the peak of the transmission curve of the etalon. When this misalignment occurs, operation deteriorates. By monitoring ...

A practical, manufacturable Fabry-Perot etalon and method for fabricating the same is disclosed. The plastic coating material is removed from the ends of a predetermined length of single mode fiber. A small area of the glass fiber is exposed by scraping away the coating near the center of the fiber on one side, and the fiber is then broken at this point forming a small gap. The remaining coating holds the broken fiber together and automatically matches the pieces in alignment. Mirrors of desired...

A temperature-stable and temperature-tunable composite etalon with an increased field of view is constructed by partially filling the cavity with a transmissive parallel-plate filler. The coefficient of thermal expansion and the index of refraction of the filler material are selected so as to produce the desired rate of change of the optical length of the cavity as a function of temperature. The filler plate is preferably chosen to be significantly thicker than the remaining air gap in the etalo...

In embodiments of the invention, a wavelength-selective device is doped with n-type or p-type material to make the single-crystal silicon in the active region of the device electrically conductive. An electrically conductive and thermally conductive active region allows an external heater such as a platinum heater strip to be eliminated and current to be applied directly to the single-crystal silicon to thermally tune the laser.

A stepped etalon having a top surface and two bottom surfaces that are parallel to the top surface and are each positioned at different distances from the top surface. Each bottom surface has an edge, wherein the edges face one another and a sloping step is positioned between the two edges so that rays from a beam of light projected onto the top surface of the etalon strike the step at the Brewster angle and pass through the etalon without any light being reflected back therein.

A single-longitudinal-mode laser comprises a laser medium, an etalon, and a resonator. The etalon is located in the resonator in a state such that two light passage end faces of the etalon, which are parallel to each other, may make a predetermined angle with respect to a resonator axis. The longitudinal mode of the etalon coincides with a gain peak wavelength of the laser medium. The single-longitudinal-mode laser is free from the problems in that the threshold value of the pumping power for th...

An active etalon comprising a laser gain chip interposed between an input mirror and an etalon end mirror is provided. In an intracavity frequency-doubled solid-state laser, a pump source emits pump radiation which passes through the input mirror and into the laser gain chip. The laser gain chip lases in response to the pump radiation to produce fundamental laser light. The etalon end mirror reflects a portion of the fundamental laser light back into the laser gain chip and transmits the remaini...

The liquid crystal device has a pair of flat glass substrates, a pair of dielectric multilayer film mirror, a plurality of transparent electrodes arranged in a matrix, a plurality of minute insulating films formed on inner face of the glass substrates, and a liquid crystal layer. A pair of dielectric multilayer film mirror constitute a Fabry-Perot etalon via the liquid crystal layer and enhance a contrast ratio. The minute insulating films are formed by physical vapor deposition and attain a uni...