Abstract: An attenuation optical system is in a beam path of a light beam traveling through a regenerative ring resonator. The attenuation optical system includes an actuator configured to receive an electromagnetic signal; and a plate mounted to the actuator to be moveable between a plurality of positions, with each position placing an attenuation region in the beam path such that the beam profile is covered by the attenuation region and each attenuation region representing an attenuation factor applied to the light beam as determined by a geometry of the attenuation region. At least one attenuation region includes a plurality of evenly-spaced elongated openings between solid energy-reflecting surfaces and at least one attenuation region includes an open area that is larger than the beam profile of the light beam.

Abstract: An optical coating and method for coating an optical element are disclosed. The optical element substrate may be made of fused silica and the coating may include a non-fluoride adherence layer such as SiO2 that is deposited on the substrate to overlay and contact a surface of the substrate. The coating may further include a multilayer system having at least one layer of a dielectric fluoride material, the multilayer system overlaying the non-fluoride adherence layer.

Abstract: A wavemeter and method for measuring bandwidth for a high repetition rate gas discharge laser having an output laser bean comprising a pulsed output of greater than or equal to 15 mJ per pulse, sub-nanometer bandwidth tuning range pulses having a femptometer bandwidth precision and tens of femptometers bandwidth accuracy range, for measuring bandwidth on a pulse to pulse basis at pulse repetition rates of 4000 Hz and above, is disclosed which may comprise a focusing lens having a focal length; an optical interferometer creating an interference fringe pattern; an optical detection means positioned at the focal length from the focusing lens; and a bandwidth calculator calculating bandwidth from the position of interference fringes in the interference fringe pattern incident on the optical detection means, defining a DID and a DOD, the respective distances between a pair of first fringe borders and between a pair of second fringe borders in the interference pattern on an axis of the interference pattern, and acc

Abstract: A spectral analysis module, including a wavemeter, for a high repetition rate gas discharge laser having a laser output beam comprising a pulsed output of greater than or equal to 15 mJ per pulse, sub-nanometer bandwidth tuning range pulses having a femptometer bandwidth precision and tens of femptometers bandwidth accuracy range, for measuring bandwidth on a pulse to pulse basis at pulse repetition rates of 4000 Hz and above, is disclosed which may comprise a primary beam-splitter in the path of the laser output laser of the gas discharge laser operative to pass the vast majority of the output beam and to reflect a first small portion of the output beam, the primary beam splitter oriented at an angle to sufficiently reduce the fluence on the primary beam-splitter, and creating overlapping fresnel reflections in the first small portion of the laser output beam; a secondary beam splitter made from a material having a damage threshold sufficiently high to tolerate the fluence created by the overlapping portion

Abstract: A wavemeter and method for measuring bandwidth for a high repetition rate gas discharge laser having an output laser beam comprising a pulsed output of greater than or equal to 15 mJ per pulse, sub-nanometer bandwidth tuning range pulses having a femptometer bandwidth precision and tens of femptometers bandwidth accuracy range, for measuring bandwidth on a pulse to pulse basis at pulse repetition rates of 4000 Hz and above, is disclosed which may comprise a focusing lens having a focal length; an optical interferometer creating an interference fringe pattern; an optical detection means positioned at the focal length from the focusing lens; and a bandwidth calculator calculating bandwidth from the position of interference fringes in the interference fringe pattern incident on the optical detection means, defining a DID and a DOD, the respective distances between a pair of first fringe borders and between a pair of second fringe borders in the interference pattern on an axis of the interference pattern, and acc