Abstract: A method and system for determining dimensions of optically recognizable features provides a low-cost and efficient high speed/high resolution measurement system for determining surface feature dimensions. Multiple imaging subsystems are arranged at predetermined differing angles above a surface under test. A scanning subsystem moves either the imaging subsystems or the surface under test and a processor coupled to the imaging subsystems determines the height of a surface feature by determining the deviations between the outputs of the imaging systems as an edge of the surface feature passes within the optical paths of the imaging subsystems.

Abstract: An optical inspection method and apparatus having an enhanced height sensitivity region and roughness filtering uses a Fabry-Perot cavity to increase the phase detection sensitivity for light reflected from surface defects having a height above a predetermined level. A partially reflective surface is inserted between an illumination subsystem and a surface under inspection. The position of the partially reflective surface with respect to the surface under inspection is adjusted to provide both filtering of defects below the predetermined level and enhance sensitivity for a region of defect heights above the predetermined level. The angular resolution of the inspection system is improved, providing far-field inspection that can detect small-profile defects having unacceptable heights. Media storage, semiconductor wafer and other precision surface manufacture may be improved by use of the techniques of the present invention.

Abstract: An optical storage method and apparatus having enhanced resolution uses a Fabry-Perot cavity to narrow a beam used for reading data stored on media. The method and apparatus achieve an enhanced resolution due to the reduction of beam size and the increased slope of the beam profile in a beam used to illuminate physical changes in the media corresponding to data encoded in the media. The Fabry-Perot cavity may be included in a media for use with standard optical storage devices or may be external to the media, as part of an optical storage head for use with standard media.

Abstract: A method and system for determining dimensions of optically recognizable features provides a low-cost and efficient high speed/high resolution measurement system for determining surface feature dimensions. Multiple imaging subsystems are arranged at predetermined differing angles above a surface under test. A scanning subsystem moves either the imaging subsystems or the surface under test and a processor coupled to the imaging subsystems determines the height of a surface feature by determining the deviations between the outputs of the imaging systems as an edge of the surface feature passes within the optical paths of the imaging subsystems.

Abstract: An optical measurement and inspection method and apparatus having enhanced path length detection uses a Fabry-Perot cavity to increase the phase detection sensitivity for light reflected from optical structures within a device under inspection. A partially reflective surface is inserted between an illumination subsystem and the device under inspection and the position of the partially reflective surface may be adjusted by a positioner to create the Fabry-Perot cavity between one or more surfaces within the device under inspection. The detection of phase changes is improved, providing improved sensitivity to optical path differences produced by structures within the device under inspection.

Abstract: An optical inspection method and apparatus having an enhanced height sensitivity region and roughness filtering uses a Fabry-Perot cavity to increase the phase detection sensitivity for light reflected from surface defects having a height above a predetermined level. A partially reflective surface is inserted between an illumination subsystem and a surface under inspection. The position of the partially reflective surface with respect to the surface under inspection is adjusted to provide both filtering of defects below the predetermined level and enhance sensitivity for a region of defect heights above the predetermined level. The angular resolution of the inspection system is improved, providing far-field inspection that can detect small-profile defects having unacceptable heights. Media storage, semiconductor wafer and other precision surface manufacture may be improved by use of the techniques of the present invention.

Abstract: An optical measurement and inspection method and apparatus having enhanced path length detection uses a Fabry-Perot cavity to increase the phase detection sensitivity for light reflected from optical structures within a device under inspection. A partially reflective surface is inserted between an illumination subsystem and the device under inspection and the position of the partially reflective surface may be adjusted by a positioner to create the Fabry-Perot cavity between one or more surfaces within the device under inspection. The detection of phase changes is improved, providing improved sensitivity to optical path differences produced by structures within the device under inspection.

Abstract: A system of beam narrowing for resolution enhancement produces a narrowed beam for use in surface imaging. The system of beam narrowing for resolution enhancement uses a Fabry-Perot cavity to sharpen the intensity profile of a light source imaged through the system. The optical distance between reflective surfaces forming the Fabry-Perot cavity is tuned to select one of the surfaces as a target surface. The beam width is thereby optimized to a minimum width at the selected target surface. Multiple Fabry-Perot cavities can be cascaded by interposing one or more additional partly reflective surfaces between a first surface and a second underlying surface. The optical distances between all of the surfaces are tuned to select a target surface. The beam width is optimized at the selected target surface to produce a beam narrower than the beam produced by a single Fabry-Perot cavity.

Abstract: An optical storage method and apparatus having enhanced resolution uses a Fabry-Perot cavity to narrow a beam used for reading data stored on media. The method and apparatus achieve an enhanced resolution due to the reduction of beam size and the increased slope of the beam profile in a beam used to illuminate physical changes in the media corresponding to data encoded in the media. The Fabry-Perot cavity may be included in a media for use with standard optical storage devices or may be external to the media, as part of an optical storage head for use with standard media.

Abstract: A system of beam narrowing for resolution enhancement produces a narrowed beam for use in surface imaging. The system of beam narrowing for resolution enhancement uses a Fabry-Perot cavity to sharpen the intensity profile of a light source imaged through the system. The optical distance between reflective surfaces forming the Fabry-Perot cavity is tuned to select one of the surfaces as a target surface. The beam width is thereby optimized to a minimum width at the selected target surface. Multiple Fabry-Perot cavities can be cascaded by interposing one or more additional partly reflective surfaces between a first surface and a second underlying surface. The optical distances between all of the surfaces are tuned to select a target surface. The beam width is optimized at the selected target surface to produce a beam narrower than the beam produced by a single Fabry-Perot cavity.