Abstract: Three-dimensional grating device includes two (crossed) diffraction gratings, exhibits diffraction efficiency substantially independent of the incident polarization inside an optical communication spectral window from 1.5-1.6 ?m. The gratings are characterized by different periods in two directions, chosen to support only one dispersive diffraction order in addition to the zero-(specular) order. Gratings may be orthogonal. Exemplary grating profiles include but are not limited to sinusoidal and truncated pyramidal (trapezoidal) profiles. A method for diffracting polarization independent light with 90% or higher efficiency. Applications include various wavelength control devices particularly useful in telecommunications.

Abstract: A reflection grating device with a continuous non-reflecting dielectric adjusting layer disposed between a grating structure and one or more continuous reflecting layers is disclosed that operates in an order of interest, such as the 1st order or 3rd order of diffraction, with high efficiency and near-exclusion of unwanted orders. Such devices can be employed, for example, in telecommunication and laser applications.

Abstract: An excimer laser cavity is disclosed which includes at least one grating-prism (grism) and a wavelength-selective diffraction grating arranged in sequence. The grism grating surface faces the gain medium and produces an expanded beam which is diffracted on the same side of the prism grating surface normal as the incident beam. The expanded diffracted beam is transmitted through a second surface of the grism either to another grating surface of an additional grism or to a wavelength-selective diffraction grating operating in Littrow configuration. The laser produces a laser output beam with a narrow spectral linewidth which is suitable, in particular, for lithography applications.

Abstract: A double-layer grating structure for efficient retroreflection of incident radiation and efficient transmission of the undiffracted incident radiation is disclosed. The grating is constructed of two spaced-apart layers of periodically arranged metal stripes, wherein the stripes in one layer overlap with gaps between the stripes in the second layer. The layers are encapsulated with a dielectric material. A method for producing such grating is also described.

Abstract: An excimer laser cavity is disclosed which includes at least one grating-prism (grism) and a wavelength-selective diffraction grating arranged in sequence. The grism grating surface faces the gain medium and produces an expanded beam which is diffracted on the same side of the prism grating surface normal as the incident beam. The expanded diffracted beam is transmitted through a second surface of the grism either to another grating surface of an additional grism or to a wavelength-selective diffraction grating operating in Littrow configuration. The laser produces a laser output beam with a narrow spectral linewidth which is suitable, in particular, for lithography applications.

Abstract: Three-dimensional grating device includes two (crossed) diffraction gratings, exhibits diffraction efficiency substantially independent of the incident polarization inside an optical communication spectral window from 1.5-1.6 ?m. The gratings are characterized by different periods in two directions, chosen to support only one dispersive diffraction order in addition to the zero- (specular) order. Gratings may be orthogonal. Exemplary grating profiles include but are not limited to sinusoidal and truncated pyramidal (trapezoidal) profiles. A method for diffracting polarization independent light with 90% or higher efficiency. Applications include various wavelength control devices particularly useful in telecommunications.

Abstract: A reflection grating device with a continuous non-reflecting dielectric adjusting layer disposed between a grating structure and one or more continuous reflecting layers is disclosed that operates in an order of interest, such as the 1st order or 3rd order of diffraction, with high efficiency and near-exclusion of unwanted orders. Such devices can be employed, for example, in telecommunication and laser applications.

Abstract: A double-grating excimer laser cavity is disclosed which includes a first multilayer dielectric diffraction grating comprised of a dielectric stack having a plurality of continuous layers with alternating high and low refractive indices, and a nonmetallic diffraction grating disposed on the top layer of the plurality of layers. The nonmetallic diffraction grating is a single pair of layers made of a low refractive index dielectric material and a high refractive index dielectric material. Grooves extend through the pair of layers. The diffraction grating has a diffraction efficiency of greater than 85% at the laser emission wavelength. The laser produces a laser output beam with a narrow spectral linewidth which is suitable, in particular, for lithography applications.

Abstract: An amplified commonly mode-locked and/or Q-switched external cavity laser device with a plurality of gain elements and a plurality of amplifying elements is described. The device produces amplified optical pulses of picosecond to nanoseconds duration. The amplified pulses can be used in applications requiring large optical pulse energy and also high average optical power, such as material processing, nonlinear optics, extreme UV spectroscopy, and generation of x-rays.

Abstract: A multi-wavelength, commonly mode-locked external cavity laser system includes a solid state gain element generating a collinearly propagating multi-wavelength optical beam, a diffracting element that diffracts the multi-wavelength optical beam into a plurality of diffracted optical beams, a wavelength-selective device receiving the plurality of diffracted optical beams and controllably transmitting or reflecting the diffracted optical beams depending on their wavelengths, and at least one mode-locking device that mode-locks the optical beams from the gain elements in common and thus forms a mode-locked optical output beam of picosecond or femtosecond duration and high peak power.

Abstract: A grating structure with a dielectric coating is disclosed that operates efficiently away from the blaze angle in low order with a high diffraction efficiency and high wavelength dispersion. Such grating structure can be employed in Littrow configuration to provide, for example, cavity feedback in excimer lasers.

Abstract: A lamellar volume grating operating in reflection and transmission and providing a substantially wavelength- and polarization-independent diffraction efficiency is disclosed. The lamellar grating has an approximately rectangular grating profile with a height-to-width ratio of the grooves or “teeth” advantageously greater than 2. The grating operates preferably in first order and can be implemented as an immersion grating. In particular, the lamellar volume grating described herein can be employed in an optical multiplexer/demultiplexer arrangement with small overall dimensions.

Abstract: A high-power pulsed laser source has a plurality of synchronized gain elements, such as optical fibers, wherein the radiation emitted by the gain elements is combined into an overlapping output beam having a predetermined temporal characteristic. The multi-element laser source can be injection-seeded by short pulses from a seed laser or can operate as a synchronized Q-switched source. The disclosed laser source is suitable for optical pumping of short wavelength plasma sources.

Abstract: A multi-wavelength external cavity laser system is disclosed, wherein an array of individual laser elements is placed in a shared laser cavity for all wavelengths that is defined by a free space grating, an optional reflector, and a single relay lens. Laser radiation from the cavity can be externally modulated at each wavelength and outputted as an overlapping beam having substantially all the wavelengths produced by the laser elements through a single fiber or as an array of wavelength-separated beams. A modular design facilitates the addition and/or repair of individual or several channels.

Abstract: A multi-wavelength external cavity fiber laser system is disclosed. Laser radiation from the cavity can be externally modulated at each wavelength and outputted as an overlapping beam having substantially all the wavelengths produced by the laser elements through a single fiber or as an array of wavelength-separated beams. The fiber laser can include an intra-cavity etalon that allows all wavelength to be tuned simultaneously.

Abstract: A grating structure with a dielectric coating is disclosed that operates efficiently away from the blaze angle in low order with a high diffraction efficiency and high wavelength dispersion. Such grating structure can be employed in Littrow configuration to provide, for example, cavity feedback in excimer lasers.

Abstract: A tunable external cavity multi-wavelength laser device employs a stationary, electrically and/or thermally tunable solid state immersion grating as a wavelength-selective element. The laser device significantly reduces the number of lasers required to span the ITU grid in DWDM applications.

Abstract: A lamellar volume grating operating in reflection and transmission and providing a substantially wavelength- and polarization-independent diffraction efficiency is disclosed. The lamellar grating has an approximately rectangular grating profile with a height-to-width ratio of the grooves or “teeth” advantageously greater than 2. The grating operates preferably in first order and can be implemented as an immersion grating. In particular, the lamellar volume grating described herein can be employed in an optical multiplexer/demultiplexer arrangement with small overall dimensions.

Abstract: A grating structure useful for WDM multiplexer/demultiplexer applications is described. The grating structure has a substantially polarization-independent diffraction efficiency of a predetermined useful wavelength range, for example, between 1.4 and 1.6 &mgr;m. Each grating period includes a triangular section and a flat-topped section, with the width of the flat-topped section between 20 and 50% of the grating period. The disclosed grating structure can be formed in any material that is substantially transparent over the useful wavelength range and used in either a Littrow and a Littman-Metcalf configuration.

Abstract: A grating structure useful for WDM multiplexer/demultiplexer applications is described. The grating structure has a substantially polarization-independent diffraction efficiency of a predetermined useful wavelength range, for example, between 1.4 and 1.6 &mgr;m. Each grating period includes a triangular section and a flat-topped section, with the width of the flat-topped section between 20 and 50% of the grating period. The disclosed grating structure can be formed in any material that is substantially transparent over the useful wavelength range and used in either a Littrow and a Littman-Metcalf configuration.