Abstract:
An apparatus for generating filtered light may include a broadband illumination source configured to generate broadband illumination and a total internal reflection (TIR) filter formed from a material at least partially transparent to the broadband illumination. The TIR filter may include one or more input faces oriented to receive the broadband illumination. The TIR filter may further be oriented to reflect wavelengths of the broadband illumination beam below a selected cutoff wavelength on one or more filtering faces as filtered broadband illumination and provide the filtered broadband illumination beam through one or more output faces. The cutoff wavelength may further be selected based on total internal reflection on the one or more faces.
Abstract:
A plasma light source with lamp house correction is disclosed. The system may include a pump source configured to generate pump illumination. The pump illumination may be directed, by an elliptical reflector element, to a volume of gas contained within a plasma lamp in order to generate a plasma. The plasma may be configured to generate broadband illumination. The system may also include a correction plate and/or an aspherical elliptical reflector element configured to alter the pump illumination to correct for aberrations introduced by the plasma lamp. The system may also include an additional aspherical correction plate configured to alter the broadband illumination to correct for aberrations introduced by optical elements of the system.
Abstract:
A spectrometer apparatus is disclosed. The apparatus may include light source and the light source may include a chamber for sustaining a plasma within the internal volume of the chamber. The apparatus may also include a spectrometer cavity and a windowless entrance slit. The windowless entrance slit may fluidically and optically couple the spectrometer cavity and the internal volume of the chamber of the light source. Further, the apparatus may include a diffractive element disposed within the spectrometer cavity and a window positioned at an opposite end of the spectrometer cavity from the windowless slit. The apparatus may also include a camera and a spectrometer.
Abstract:
An optical system for generating broadband light via light-sustained plasma formation includes a chamber, an illumination source, a set of focusing optics, and a set of collection optics. The chamber is configured to contain a buffer material in a first phase and a plasma-forming material in a second phase. The illumination source generates continuous-wave pump illumination. The set of focusing optics focuses the continuous-wave pump illumination through the buffer material to an interface between the buffer material and the plasma-forming material in order to generate a plasma by excitation of at least the plasma-forming material. The set of collection optics receives broadband radiation emanated from the plasma.
Abstract:
A broadband radiation source is disclosed. The system may include a plasma containment vessel configured to receive laser radiation from a pump source to sustain a plasma within gas flowed through the plasma containment vessel. The plasma containment vessel may be further configured to transmit at least a portion of broadband radiation emitted by the plasma. The system may also include a recirculation gas loop fluidically coupled to the plasma containment vessel. The recirculation gas loop may be configured to transport heated gas from an outlet of the plasma containment vessel, and further configured to transport cooled gas to an inlet of the plasma containment vessel.
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:
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:
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.