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.

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.

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.

The present disclosure provides a dark cavity laser, including: a frequency stabilized laser output device configured to generate a laser light, and perform a frequency stabilized processing on the generated laser light to output it to the dark cavity laser device as a pump light of a gain medium of a dark cavity; and a dark cavity laser device including a main cavity, and a cavity of the main cavity is provided inside with a gas chamber of a gain medium of a dark cavity laser light, where the gain medium of the dark cavity laser light is alkali metal atoms; the dark cavity laser device is configured to receive the pump light, and form a polyatomic coherent stimulated radiation between transition levels of the alkali metal atoms in the gas chamber by a weak feedback of the main cavity to generate the dark cavity laser light.

The laser apparatus includes a master oscillator, an amplifier, a power source, and a controller to control the power source. The controller controls the power source such that an excitation intensity of the amplifier in a burst oscillation period performing the burst oscillation is a first excitation intensity, controls the power source such that, if the predetermined repetition frequency is a first repetition frequency, an excitation intensity of the amplifier in a suspension period suspending the burst oscillation is a second excitation intensity equal to or lower than the first excitation intensity, and controls the power source such that, if the predetermined repetition frequency is a second repetition frequency higher than the first repetition frequency, the excitation intensity of the amplifier in the suspension period is a third excitation intensity lower than the second excitation intensity.

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.

An improved dental laser system has been developed to cut enamel quickly and precisely, without detrimental residual energy, to provide a replacement for conventional high speed rotary burrs and commercially available dental laser systems.