Bandwidth measuring device for high pulse repetition rate pulsed laser
AssigneeCymer, Inc.
InventorRobert J. Rafac
Life of this patent
Estimating the term…
Abstract
A method and apparatus for estimating bandwidth of laser output light is described which may include a dispersive element producing a dispersed output having a plurality of spectrum images from at least a portion of the laser output light. An array of light detecting elements is oriented to receive the dispersed output together with a shifting mechanism that moves the array, the dispersed output, or both, relative to each other. Electronics may be provided for determining the widths of at least two spectrum images at different phases of registration between the spectrum images and light detector elements and for averaging the widths to estimate a laser output bandwidth. The-spectrum images formed by the laser output light may be under-sampled, e.g., in the spatial or time domains.
Claims37
A method for estimating bandwidth of laser output light comprising:
- passing at least a portion of the laser output light to a spectrometer to produce a plurality of spectrum images representative of the output light spectrum;
- directing the spectrum images to an array of light detecting elements;
- determining widths of at least two spectrum images at different phases of registration between the spectrum images and light detector elements;
- and
- averaging the widths to estimate a laser output bandwidth.
A device for estimating bandwidth of laser output light comprising:
- means for producing a plurality of spectrum images from at least a portion of the laser output light;
- means for directing the spectrum images to an array of light detecting elements;
- means for determining widths of at least two spectrum images at different phases of registration between the spectrum images and light detector elements;
- and
- means for averaging the widths to estimate a laser output bandwidth.
A device for estimating bandwidth of laser output light comprising:
- An optical element producing a dispersed output having a plurality of spectrum images from at least a portion of the laser output light;
- an array of light detecting elements receiving the dispersed output;
- a shifting mechanism moving at least one of the array and the dispersed output relative to the other;
- and
- electronics determining widths of at least two spectrum images at different phases of registration between the spectrum Images and light detector elements and averaging the widths to estimate a laser output bandwidth.
Dependencies are inferred from the claim text.