Abstract: A bandwidth meter method and apparatus for measuring the bandwidth of a spectrum of light emitted from a laser input to the bandwidth meter is disclosed, which may comprise an optical bandwidth monitor providing a first output representative of a first parameter which is indicative of the bandwidth of the light emitted from the laser and a second output representative of a second parameter which is indicative of the bandwidth of the light emitted from the laser; and, an actual bandwidth calculation apparatus utilizing the first output and the second output as part of a multivariable equation employing predetermined calibration variables specific to the optical bandwidth monitor, to calculate an actual bandwidth parameter.

Abstract: A bandwidth meter method and apparatus for measuring the bandwidth of a spectrum of light emitted from a laser input to the bandwidth meter is disclosed, which may comprise an optical bandwidth monitor providing a first output representative of a first parameter which is indicative of the bandwidth of the light emitted from the laser and a second output representative of a second parameter which is indicative of the bandwidth of the light emitted from the laser; and, an actual bandwidth calculation apparatus utilizing the first output and the second output as part of a multivariable equation employing predetermined calibration variables specific to the optical bandwidth monitor, to calculate an actual bandwidth parameter.

Abstract: A method and apparatus is disclosed which may comprise detecting the bandwidth of laser output light pulses of a pulsed laser utilizing an array of light detecting elements by the steps which may comprise passing a portion of the laser output light produced by the pulsed laser to the array of light detecting elements in a manner that shifts the portion of the laser beam across the array of light detecting elements to avoid aliasing artifacts in output of the light detecting array. The portion of the image formed by the laser output light may be under-sampled, e.g., in the spatial or time domains. The relevant feature size of an image of an output of a fringe pattern generating element being sampled may comprise a size that is small with respect to the size of individual light detecting elements in the array of light detecting elements. sity of the fringe image.

Abstract: An apparatus and method for controlling a laser system is disclosed which may comprise a spectrometer adapted to measure an unknown bandwidth of a spectrum of light emitted from the laser, which may comprise an optical bandwidth measuring unit adapted to provide as an output a measured parameter, which is indicative of a parameter of the unknown bandwidth of the spectrum being measured; a reported parameter computing unit adapted to compute a reported parameter of the unknown bandwidth of the spectrum being measured according to the formula: Reported Parameter(“RP”)=A*(Measured Parameter(“MP”))+C, wherein the RP and MP are a different type of parameter and the values of A and C are determined based upon calibration of the optical bandwidth measuring unit MP response for light of known valued of RP.

Abstract: A bandwidth meter apparatus and method for measuring the bandwidth of a spectrum of light emitted from a laser input to the bandwidth meter is disclosed which may comprise an optical bandwidth monitor providing a first output representative of a first parameter which is indicative of the bandwidth of the light emitted from the laser and a second output representative of a second parameter which is indicative of the bandwidth of the light emitted from the laser; and, an actual bandwidth calculation apparatus utilizing the first output and the second output as part of a multivariable equation employing predetermined calibration variables specific to the optical bandwidth monitor, to calculate an actual bandwidth parameter; the multivariable equation comprising a symmetry sensitive term.

Abstract: A method and apparatus for producing with a gas discharge laser an output laser beam comprising output laser light pulses, for delivery as a light source to a utilizing tool is disclosed which may comprise a beam path and a beam homogenizer in the beam path. The beam homogenizer may comprise at least one beam image inverter or spatial rotator, which may comprise a spatial coherency cell position shifter. The homogenizer may comprise a delay path which is longer than, but approximately the same delay as the temporal coherence length of the source beam.

Abstract: An apparatus and method are disclosed for operating a narrow band short pulse duration gas discharge laser output light pulse beam producing system, producing a beam comprising laser output light pulses at a selected pulse repetition rate, which may comprise: a dispersive center wavelength selection optic selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the laser light pulse beam containing the respective pulse on the dispersive wavelength selection optic; a tuning mechanism operative to select at least one angle of incidence of a first spatially defined portion of the laser light pulse beam containing the respective pulse upon the dispersive center wavelength selection optic; and, the tuning mechanism comprising a variably refractive optical element defining a plurality of refractive angular displacements of the first spatially defined portion of the laser light pulse beam passing through the variably refractive optical element at one of a plura

Abstract: A method and apparatus for measuring bandwidth of light emitted from a laser is disclosed which may comprise: a first and second wavelength sensitive optical bandwidth detectors providing, respectively, an output representative of a first parameter indicative of the bandwidth of the emitted light as measured respectively by the first and second bandwidth detectors, and an actual bandwidth calculation apparatus adapted to utilize these two outputs as part of a multivariable linear equation employing predetermined calibration variables specific to either the first or the second bandwidth detector, to calculate a first actual bandwidth parameter or a second actual bandwidth parameter. The first actual bandwidth parameter may be a spectrum full width at some percent of the maximum (“FWXM”), and the second actual bandwidth parameter may be a portion containing some percentage of the energy (“EX”).

Abstract: A method for stabilizing a multi-layered dielectric reflectivity coating subject to compaction/densification upon exposure to DUV or shorter wavelength light, is disclosed which may comprise: applying the reflectivity coating to a reflective surface forming a coating bulk on the surface; exposing the coating bulk to a pretreatment of a sufficient amount of DUV radiation to induce sufficient densification in enough of the coating bulk to inhibit subsequent densification during continued exposure to DUV or shorter wavelength radiation. The method may also comprise the pretreatment radiation exposure amounting to energy of at least the equivalent of about 2 Bp at 9 mJ per pulse. The method may also comprise the pretreatment radiation exposure amounting the energy being delivered in at about 3 KHz pulse repetition rate. The method may also comprise the pretreatment radiation exposure amounts to energy of at least the equivalent of 15-18 mJ per pulse delivered over about 700 M-1 B pulses, i.e.