A method for operating an excimer or molecular fluorine laser system at a stabilized wavelength includes generating a laser beam and directing a beam portion through a wavelength measurement system, calibrating the wavelength measurement system to an absolute reference, determining the wavelength of the laser beam including figuring in a drift compensation value of the wavelength, and tuning the wavelength to a target wavelength when the determined wavelength differs from the target wavelength.

A cavity thickness compensated etalon filter. A tuning medium is placed in a Fabry-Perot etalon cavity. The index of refraction of the tuning medium varies as a function of voltage applied across the medium. The etalon is formed of two generally flat substrates disposed substantially parallel to one another. Each substrate has a layer of conductive material within the cavity adjacent the substrate. Each substrate also has a layer of reflective material within the cavity adjacent the substrate. A...

An etalon includes an analyzer, a first .lambda./4 plate having an optical axis forming a 45 degree angle with respect to an optical axis of the analyzer and receiving a light transmitted via the analyzer, and a second .lambda./4 plate having an optical axis which is parallel to or 90 degrees to the optical axis of the first .lambda./4 plate and receiving a light transmitted via the first .lambda./4 plate. A reflection may occur between the first and second .lambda./4 plates.

According to the present invention, laser performance is improved by appropriately matching the spectral periods of various etalons within the laser cavity. A first embodiment of the invention is a discretely tunable external cavity semiconductor laser where a grid fixing etalon is present in the laser cavity, the grid fixing etalon free spectral range (FSR) is a whole number multiple of the laser cavity FSR, and the grid fixing etalon FSR is a whole number multiple of the chip etalon FSR. A sec...

A high resolution etalon-grating spectrometer. A preferred embodiment presents an extremely narrow slit function in the ultraviolet range and is very useful for measuring bandwidth of narrow band excimer lasers used for integrated circuit lithography. Light from the laser is focused into a diffuser and the diffused light exiting the diffuser illuminates an etalon. A portion of its light exiting the etalon is collected and directed into a slit positioned at a fringe pattern of the etalon. Light p...

The invention provides a substantially athermal etalon. In one embodiment, the multi-cavity etalon includes at least one free-standing multi-layer thin film and is rendered thermally stable through the use of the free-standing multi-layer film and spacers having predetermined thermal expansion coefficients. In another embodiment, the multi-cavity etalon is rendered thermally stable through the use of mixed spacers.

A Fabry-Perot etalon (310) has a cavity (12) occupied by an electric-field variable index of refraction material (22). The cavity is flanked by a pair of parallel mirrors (14), at least one of which is partially reflecting. At least one of the supporting substrates (18l) has deposited thereon a light polarizing field electrode (316l) which includes a plurality of mutually parallel, spaced apart electrical conductors (392) which define gaps (394). The electrical conductors are mutually interconne...

An interferometer suitable for length measurements, comprising a laser light source, a beam splitter to divide light stemming from the laser light source into a measuring beam and a reference beam, and recombination means at which the reference beam being guided along a reference path and the measuring beam interfere. The measuring beam travels along a measuring path that leads over a movable measuring reflector and partly through a gaseous ambient medium. The interferometer further comprises ph...

A tunable liquid-crystal etalon filter comprising two dielectric stack mirrors defining an optical cavity into which is filled a liquid crystal. Electrodes disposed on the outsides of the mirrors apply an electric field to the liquid crystal, changing its refractive index and thereby changing its optical length. Thereby, the optical pass band of the filter can be electrically changed in a low-powered, compact, rugged, and economical structure.

An in-line fiber etalon strain sensor, and method for making the sensor, is disclosed. The in-line fiber etalon strain sensor uses a short segment of silica hollow-core fiber spliced between two cleaved sections of single-mode fiber to form a mechanically robust in-line cavity. In making the sensor, a portion of a protective coating is removed from one end of each of the two cleaved sections of the single-mode fiber to form a bare portion adjacent to a partially reflective end face on each fiber...