Abstract: A plasma cell for use in a laser-sustained plasma light source includes a plasma bulb configured to contain a gas suitable for generating a plasma, the plasma bulb being transparent to light from a pump laser, wherein the plasma bulb is transparent to at least a portion of a collectable spectral region of illumination emitted by the plasma. The plasma bulb of the plasma cell is configured to filter short wavelength radiation, such as VUV radiation, emitted by the plasma sustained within the bulb in order to keep the short wavelength radiation from impinging on the interior surface of the bulb.

Abstract: A system for forming a laser-sustained plasma includes a gas containment element, an illumination source configured to generate pump illumination, and a collector element configured to focus the pump illumination from the pumping source into the volume of the gas mixture in order to generate a plasma within the volume of the gas mixture that emits broadband radiation. The gas containment element may be configured to contain a volume of a gas mixture including a first gas component and a second gas component. The second gas component suppresses at least one of a portion of the broadband radiation associated with the first gas component or radiation by one or more excimers associated with the first gas component from a spectrum of radiation exiting the gas mixture.

Abstract: A system for controlling convective flow in a light-sustained plasma includes an illumination source configured to generate illumination, a bulb-less gas containment structure, and a collector element arranged to focus illumination from the illumination source into the volume of gas in order to generate a plasma within the volume of gas contained within the bulb-less gas containment structure. Further, the plasma is generated within a concave region of the collector element, where the collector element includes an opening through the collector element for propagating a portion of a plume of the plasma from a first region of the bulb-less gas containment structure to a second region of the bulb-less gas containment structure, wherein the first region of the bulb-less gas containment structure and the second region of the bulb-less gas containment structure are at least partially separated by a surface of the collector element.

Abstract: A system for forming a laser-sustained plasma includes a gas containment element, an illumination source configured to generate pump illumination, and a collector element configured to focus the pump illumination from the pumping source into the volume of the gas mixture in order to generate a plasma within the volume of the gas mixture that emits broadband radiation. The gas containment element may be configured to contain a volume of a gas mixture including a first gas component and a second gas component. The second gas component suppresses at least one of a portion of the broadband radiation associated with the first gas component or radiation by one or more excimers associated with the first gas component from a spectrum of radiation exiting the gas mixture.

Abstract: A system for separating plasma pumping light and collected broadband light includes a pump source configured to generate pumping illumination including at least a first wavelength, a gas containment element for containing a volume of gas, a collector configured to focus the pumping illumination from the pumping source into the volume of gas to generate a plasma within the volume of gas, wherein the plasma emits broadband radiation including at least a second wavelength and an illumination separation prism element positioned between a reflective surface of the collector and the pump source and arranged to spatially separate the pumping illumination including the first wavelength and the emitted broadband radiation including at least a second wavelength emitted from the plasma.

Abstract: A system for forming a light-sustained plasma capable of emitting vacuum ultraviolet light includes an illumination source configured to generate illumination, a plasma cell including a transmission element having one or more openings, one or more flanges disposed at the openings of the transmission element and configured to enclose the internal volume of the transmission element in order to contain a volume of gas within the plasma cell. The system further includes a collector element arranged to focus the illumination from the illumination source into the volume of gas to generate a plasma within the volume of gas contained within the plasma cell. Further, the plasma emits broadband radiation including at least vacuum ultraviolet radiation. In addition, the transmission element of the plasma cell is transparent to the illumination generated by the illumination source and at least the vacuum ultraviolet radiation emitted by the plasma.

Abstract: Disclosed are methods and apparatus for generating a sub-200 nm continuous wave (cw) laser. A laser apparatus includes a chamber for receiving at least a rare gas or rare gas mixtures and a pump laser source for generating at least one cw pump laser focused in the chamber for generating at least one laser-sustained plasma in the chamber. The laser apparatus further includes a system for forming an optical cavity in which the at least one laser-sustained plasma serves as an excitation source for producing at least one cw laser having a wavelength that is below about 200 nm. In one aspect, the at least one laser-sustained plasma has a shape that substantially matches a shape of the optical cavity.

Abstract: A laser-sustained plasma light source for transverse plasma pumping includes a pump source configured to generate pumping illumination, one or more illumination optical elements and a gas containment structure configured to contain a volume of gas. The one or more illumination optical elements are configured to sustain a plasma within the volume of gas of the gas containment structure by directing pump illumination along a pump path to one or more focal spots within the volume of gas. The one or more collection optical elements are configured to collect broadband radiation emitted by the plasma along a collection path. Further, the illumination optical elements are configured to define the pump path such that pump illumination impinges the plasma along a direction transverse to a direction of propagation of the emitted broadband light of the collection path such that the pump illumination is substantially decoupled from the emitted broadband radiation.

Abstract: An open plasma lamp includes a cavity section. A gas input and gas output of the cavity section are arranged to flow gas through the cavity section. The plasma lamp also includes a gas supply assembly fluidically coupled to the gas input of the cavity section and configured to supply gas to an internal volume of the cavity section. The plasma lamp also includes a nozzle assembly fluidically coupled to the gas output of the cavity section. The nozzle assembly and cavity section are arranged such that a volume of the gas receives pumping illumination from a pump source, where a sustained plasma emits broadband radiation. The nozzle assembly is configured to establish a convective gas flow from within the cavity section to a region external to the cavity section such that a portion of the sustained plasma is removed from the cavity section by the gas flow.

Abstract: A system for separating plasma pumping light and collected broadband light includes a pump source configured to generate pumping illumination including at least a first wavelength, a gas containment element for containing a volume of gas, a collector configured to focus the pumping illumination from the pumping source into the volume of gas to generate a plasma within the volume of gas, wherein the plasma emits broadband radiation including at least a second wavelength and an illumination separation prism element positioned between a reflective surface of the collector and the pump source and arranged to spatially separate the pumping illumination including the first wavelength and the emitted broadband radiation including at least a second wavelength emitted from the plasma.

Abstract: A laser-sustained plasma lamp includes a gas containment structure configured to contain a volume of gas. The gas containment structure is configured to receive pump illumination from a pump laser for generating a plasma within the volume of gas. The gas containment structure includes one or more transmissive structures being at least partially transparent to the pump illumination from the pump laser and at least a portion of the broadband radiation emitted by the plasma. The one or more transmissive structures have a graded absorption profile so as to control heating of the one or more transmissive structures caused by the broadband radiation emitted by the plasma.

Abstract: Methods and systems for performing non-contact temperature measurements of optical elements with long wavelength infrared light are described herein. The optical elements under measurement exhibit low emissivity to long wavelength infrared light and are often highly reflective or highly transmissive to long wavelength infrared light. In one aspect, a material coating having high emissivity, low reflectivity, and low transmission at long wavelength IR wavelengths is disposed over selected portions of one or more optical elements of a metrology or inspection system. The locations of the material coating are outside the direct optical path of the primary measurement light employed by the metrology or inspection system to perform measurements of a specimen. Temperature measurements of the front and back surfaces of an IR-transparent optical element are performed with a single IR camera. Temperature measurements are performed through multiple optical elements in an optical path of a primary measurement beam.

Abstract: A system for providing illumination to a measurement head for optical metrology is configured to combine illumination beams from a plurality of illumination sources to deliver illumination at one or more selected wavelengths to the measurement head. The intensity and/or spatial coherence of illumination delivered to the measurement head is controlled. Illumination at one or more selected wavelengths is delivered from a broadband illumination source configured for providing illumination at a continuous range of wavelengths.

Abstract: An illumination source for igniting and sustaining a plasma in a plasma lamp of a laser-sustained plasma (LSP) broadband source includes one or more ignition lasers configured to ignite the plasma within a gas contained within the plasma lamp. The illumination sources also includes one or more sustaining lasers configured to sustain the plasma. The illumination sources includes a delivery optical fiber one or more optical elements configured to selectively optically couple an output of the one or more ignition lasers and an output of the one or more sustaining lasers to the delivery optical fiber.

Abstract: A plasma cell for controlling convection includes a transmission element configured to receive illumination from an illumination source in order to generate a plasma within a plasma generation region of the volume of gas. The transmission element of the plasma cell is at least partially transparent to at least a portion of the illumination generated by the illumination source and at least a portion of broadband radiation emitted by the plasma. The plasma cell also includes one or more gas return channels formed within the transmission element for transferring gas from a region above the plasma generation region to a region below the plasma generation region.

Abstract: A system for forming a laser-sustained plasma includes a gas containment element, an illumination source configured to generate pump illumination, and a collector element. The gas containment element is configured to contain a volume of a gas mixture. The collector element is configured to focus the pump illumination from the pumping source into the volume of the gas mixture contained within the gas containment element in order to generate a plasma within the volume of the gas mixture that emits broadband radiation. The gas mixture filters one or more selected wavelengths of radiation emitted by the plasma.

Abstract: An illumination pump source is disclosed. The illumination pump source includes a set of power sources configured to generate a set of laser beams, with at least some of the set of laser beams configured to include illumination having different wavelengths. The illumination pump source also includes an optical fiber. The illumination pump source also includes one or more optical elements, the one or more optical elements configured to couple the illumination from at least some of the laser beams to one or more regions of the optical fiber.

Abstract: A system for illuminating a sample with a spectrally filtered illumination source includes an illumination source configured to generate a beam of illumination having a first set of wavelengths. In addition, the system includes a wavelength filtering sub-system, a sample stage, an illumination sub-system, a detector, and an objective to focus illumination from the surface of one or more samples and focus the collected illumination to the detector. Further, the wavelength filtering sub-system includes one or more first dispersive elements positioned to introduce spatial dispersion into the beam, a spatial filter element, and one or more dispersive elements positioned to remove spatial dispersion from the beam. The spatial filter element is further positioned to pass at least a portion of the beam including a second set of wavelengths, wherein the second set of wavelengths is a subset of the first set of wavelengths.

Abstract: The inspection of a sample with VUV light from a laser sustained plasma includes generating pumping illumination including a first selected wavelength, or range of wavelength, containing a volume of gas suitable for plasma generation, generating broadband radiation including a second selected wavelength, or range of wavelengths, by forming a plasma within the volume of gas by focusing the pumping illumination into the volume of gas, illuminating a surface of a sample with the broadband radiation emitted from the plasma via an illumination pathway, collecting illumination from a surface of the sample, focusing the collected illumination onto a detector via a collection pathway to form an image of at least a portion of the surface of the sample and purging the illumination pathway and/or the collection pathway with a selected purge gas.

Abstract: A fluid input manifold distributes injected fluid around the body of a bulb to cool the bulb below a threshold. The injected fluid also distributes heat more evenly along the surface of the bulb to reduce thermal stress. The fluid input manifold may comprise one or more airfoils to direct a substantially laminar fluid flow along the surface of the bulb or it may comprise a plurality of fluid injection nozzles oriented to produce a substantially laminar fluid flow. An output portion may be configured to facilitate fluid flow along the surface of the bulb by allowing injected fluid to easily escape after absorbing heat from the bulb or by applying negative pressure to actively draw injected fluid along the surface of the bulb and away.