Abstract: The invention features an imaging system for imaging an object point to an image point. The system includes: a beam splitter positioned to receive light rays from the object point and separate each ray into a transmitted portion and a reflected portion, the transmitted portions defining a first set of rays and the reflected portions defining a second set of rays; and a reflecting surface positioned to receive one of the sets of rays from the beam splitter and focus that set of rays towards the image point via the beam splitter.

Abstract: The invention features systems and methods for near-field, interferometric microscopy in which one or more phase retardation plates are positioned in the measurement and/or reference arms to reduce the contribution to the interference signal of background sources including, e.g., a beam component scattered from a near-field aperture used to couple a probe beam to a sample. The systems may operate in either reflective or transmissive modes.

Abstract: A near-field, interferometric optical microscopy system includes: a beam splitter positioned to separate an input beam into a measurement beam and a reference beam; a mask positioned to receive the measurement beam, the mask comprising at least one aperture having a dimension smaller than the wavelength of the input beam, wherein the mask aperture is configured to couple at least a portion of the measurement beam to a sample to define a near-field probe beam, the sample interacting with the near-field probe beam to define a near-field signal beam; a detector having an element responsive to optical energy; and optics positioned to direct at least a portion of the reference beam and at least a portion of the near-field signal beam to interfere at the detector element.

Abstract: A near-field, interferometric optical microscopy system includes: a beam splitter positioned to separate an input beam into a measurement beam and a reference beam; a mask positioned to receive the measurement beam, the mask comprising at least one aperture having a dimension smaller than the wavelength of the input beam, wherein the mask aperture is configured to couple at least a portion of the measurement beam to a sample to define a near-field probe beam, the sample interacting with the near-field probe beam to define a near-field signal beam; a detector having an element responsive to optical energy; and optics positioned to direct at least a portion of the reference beam and at least a portion of the near-field signal beam to interfere at the detector element.

Abstract: Systems and methods for near-field, interferometric microscopy are disclosed in which a mask having an array of sub-wavelength apertures is used to couple near-field probe beams to a sample. The periphery of the mask further includes one or more larger apertures to couple light to the sample that forms the basis of an interferometric signal indicative of the relative distance between the mask and the sample. The interferometric signal can be the basis of a control signal in a servo system that dynamically positions the mask relative to the sample.

Abstract: The invention features an imaging system for imaging an object point to an image point. The system includes: a beam splitter positioned to receive light rays from the object point and separate each ray into a transmitted portion and a reflected portion, the transmitted portions defining a first set of rays and the reflected portions defining a second set of rays; and a reflecting surface positioned to receive one of the sets of rays from the beam splitter and focus that set of rays towards the image point via the beam splitter. Interferometric techniques may be applied to increase the light throughput of the system.

Abstract: An in-focus image of an information-bearing region within and/or on a substance is discriminated from an out-of-focus image so as to reduce errors in image information of the substance by producing a probe beam and a reference beam from a wideband point source, producing antisymmetric spatial properties in the reference beam, converting the probe beam to a beam focused to a line in the region, producing an in-focus return probe beam, and producing antisymmetric spatial properties in the in-focus return probe beam. Then the in-focus return probe beam is spatially filtered and focused to a line image in a detector plane of a detector system. The reference beam is spatially filtered and focus to a line image in the detector plane. A beam from an out-of focus image point is spatially filtered. The line image of the spatially filtered reference beam is interfered with the spatially filtered beam from the out-of-focus image point and the line image of the spatially filtered in-focus return probe beam.

Abstract: A near-field, interferometric optical microscopy system includes: a beam splitter positioned to separate an input beam into a measurement beam and a reference beam; a mask positioned to receive the measurement beam, the mask comprising at least one aperture having a dimension smaller than the wavelength of the input beam, wherein the mask aperture is configured to couple at least a portion of the measurement beam to a sample to define a near-field probe beam, the sample interacting with the near-field probe beam to define a near-field signal beam; a detector having an element responsive to optical energy; and optics positioned to direct at least a portion of the reference beam and at least a portion of the near-field signal beam to interfere at the detector element.

Abstract: An in-focus image of an information-bearing region within an optical memory medium is discriminated from an out-of-focus image so as to reduce errors in reading information represented by the information-bearing region within the optical memory medium by producing a probe beam and a reference beam from a wideband point source, producing antisymmetric spatial properties in the reference beam, converting the probe beam to a beam focused to a line in the information-bearing region, producing an in-focus return probe beam, and producing antisymmetric spatial properties in the in-focus return probe beam. Then the in-focus return probe beam is spatially filtered and passed through a dispersal element to focus it to a line in a detector plane. The reference beam is spatially filtered and passed through a dispersal element to focus it to the line in the detector plane. A beam from an out-of focus image point is spatially filtered and passed through a dispersal element.

Abstract: A method and apparatus for discriminating an in-focus image from an out-of-focus image which may be implemented in accordance with either or both an illumination procedure and a signal detection procedure includes collimating light rays emanating from a point in an object plane in an object to produce collimated rays. The collimated rays are focused onto a spot in an in-focus image plane. Light impinging on the spot is detected to measure the intensity thereof. The phase of a first portion of the collimated rays is shifted to produce a first quantity of phase-shifted rays, and the phase of a second portion of the collimated rays also is shifted to produce a second quantity of phase-shifted rays. The first and second quantities of phase-shifted rays are focused onto the spot. Light including the remaining non-phase-shifted rays and the first and second quantities of phase-shifted rays impinging on the spot is detected to measure the intensity thereof.

Abstract: A system discriminates an in-focus image from an out-off-focus image so as to reduce both systematic and statistical errors in a measurement of the in-focus image. The system produces a probe beam and a reference beam from a point source, and antisymmetric spatial properties are produced in the reference beam. An in-focus return probe beam is produced as a result of directing a probe beam into an in-focus image point, and antisymmetric spatial properties are produced in the in-focus return probe beam. The reference beam is interfered with a beam from an out-of-focus image point, and the reference beam is interfered with the in-focus return probe beam. The reference beam is detected by a single-pixel detector as a square of an amplitude of the reference beam, and the in-focus return probe beam is detected by the detector as an interference term between a return reference beam and the in-focus return probe beam.

Abstract: A high resolution optical coupling device includes optical coupling material bonded to a CCD wafer surface and a fiber optic bundle. The CCD wafer is bonded to a substrate, and a thermal compensation plate is bonded to an opposite face thereof to compensate effects of differential thermal contraction and expansion of the CCD wafer and substrate. Substrate-adjusting elements engage the substrate to shape the CCD wafer surface to match a mating surface of a fiber optic bundle before the thermal compensation plate is attached to the substrate. A null fringe pattern of an interferometer indicates when a perfect match is achieved. A thin layer of optical coupling material then is used to bond the CCD surface to the matching surface of the optic fiber bundle. Thermal compensation material can be included in a rigid hermetic seal structure between the substrate and the fiber optic bundle to reduce bonding interface shear stress in the optical coupling material due to volume changes thereof during thermal cycling.