An extreme ultraviolet light (EUV) generation system is configured to improve conversion efficiency of energy of a laser system to EUV energy by improving the efficiency of plasma generation. The EUV generation system includes a target generation unit configured to output a target toward a plasma generation region in a chamber. The laser system is configured to generate a first pre-pulse laser beam, a second pre-pulse laser beam, and a main pulse laser beam so that the target is irradiated with the first pre-pulse laser beam, the second pre-pulse laser beam, and the main pulse laser beam in this order. In addition, the EUV generation system includes a controller configured to control the laser system so that a fluence of the second pre-pulse laser beam is equal to or higher than 1 J/cm.sup.2 and equal to or lower than a fluence of the main pulse laser beam.

A system, comprising an optical component that, in operational use of the optical component, optically interacts with a laser beam, an electrically conductive element disposed on or within the optical component that, in operational use of the optical component, is exposed to the laser beam, and a monitoring system operative to monitor a physical quantity representative of an electrical resistance of the electrically conductive element and to determine based on the physical quantity, a position of the laser beam relative to the optical component.

A laser apparatus includes: a master oscillator for emitting a laser beam; an amplifier on an optical path of the laser beam; a beam splitter between the master oscillator and the amplifier for separating, from the optical path of the laser beam, at least part of a return beam traveling through the optical path of the laser beam in a direction opposite to a traveling direction of the laser beam; a focusing optical system for focusing the return beam separated from the optical path; and an optical sensor having a light receiving surface for the return beam for detecting information on power of the return beam entering the light receiving surface through the focusing optical system, the light receiving surface being arranged at a position different from a focusing position of the focusing optical system on the optical path of the return beam.

A laser resonator comprising a specially designed front mirror 32. The front mirror 32 together with a rear mirror form a resonator cavity. As well as having a resonator cavity reflective surface 42, the front mirror 32 also has an output coupling reflective surface 44 which forms a continuation of the resonator cavity reflective surface 42 and extends at an angle thereto so as to direct a beam laterally out of the cavity. The output coupling reflective surface 44 and the resonator cavity reflective surface 44 are joined by a soft rounded edge 40 of arcuate cross-section, this rounded transition suppressing diffraction ripples that would otherwise be generated if the edge were hard, i.e. sharp.

The disclosed invention relates to an improved system and method for treatment of soft tissue, e.g., for treatment of a snoring condition. The system can include a laser source; a hand piece; and a device for directing radiation emitted by the laser source to a treatment area (e.g., an oral treatment area). In some cases, the handpiece can include an optical element (e.g., a lens) mounted within a replaceable cartridge and adapted to modulate a laser beam such that it is non-ablative, prior to its delivery to a treatment region. In various embodiments, the system includes a CO2 laser capable of performing treatment in a more efficient manner than conventional techniques.

A laser may comprise a ceramic core that at least partially defines a waveguide slab laser cavity. An interior surface of the waveguide slab laser cavity is coated with a layer of metal. The laser also includes a set of mirrors that form a resonator in the waveguide slab laser cavity. The laser also includes electrodes positioned such that the laser gas contained in the waveguide slab laser cavity is excited when an excitation signal is applied to the electrodes. In other embodiments, the core may be formed from a material other than ceramic. Additionally or alternatively, the layer may be formed from a material other than metal.

A laser device, including multiple laser modules, includes a plurality of drive power units that drive the laser modules, a plurality of output detection units that detect laser outputs from the laser modules, and output detected values as first output signals, a coupled output detection unit that detects a total laser output after coupling of a plurality of the laser outputs, and outputs a detected value as a second output signal, a computing unit that sets multiple output correction factors for correspondingly controlling the laser modules using the plurality of first output signals and the second output signal, and a control unit that controls the plurality of drive power units using the multiple output correction factors. The multiple output correction factors are each set to allow the total laser output to be maintained at a constant value.

The disclosed invention relates to an improved system and method for treatment of soft tissue, e.g., for treatment of a snoring condition. The system can include a laser source; a hand piece; and a device for directing radiation emitted by the laser source to a treatment area (e.g., an oral treatment area). In some cases, the handpiece can include an optical element (e.g., a lens) mounted within a replaceable cartridge and adapted to modulate a laser beam such that it is non-ablative, prior to its delivery to a treatment region. In various embodiments, the system includes a CO2 laser capable of performing treatment in a more efficient manner than conventional techniques.

A light source apparatus includes an airtight container having a hemispherical or semielliptical first curved portion configured to receive laser light, a hemispherical or semielliptical second curved portion opposite to the first curved portion, and a cylindrical portion connecting the first curved portion and the second curved portion; assist gas sealed in the airtight container; and a light source configured to irradiate laser light to the first curved portion from outside of the airtight container.

An extreme ultraviolet light generation system according to one aspect of the present disclosure includes: a pulse laser apparatus configured to output a pulse laser beam, the pulse laser beam being supplied to a predetermined region in a chamber in which plasma containing extreme ultraviolet light is to be generated; a sensor configured to detect a beam size of the pulse laser beam; an actuator configured to change the beam size; and a controller. The controller performs, based on a first algorithm, first control that controls the actuator by a first control amount in a beam size minifying direction when the beam size has exceeded a first upper limit threshold in one burst duration, and then performs, based on a second algorithm, second control that controls the actuator by a second control amount smaller than the first control amount so that the beam size becomes closer to a target value.