Abstract: A multiwavelength holographic imaging apparatus uses a frequency converter for converting input tunable coherent light having a wavelength tunable around a wavelength ?2 to tunable output coherent light having a wavelength tunable around a wavelength ?1, wherein the image receiver receiving the holographic image is sensitive to the light of wavelength ?1. The image receiver may not be sensitive to light of wavelength ?2, for example if ?2 is in the infrared spectral region greater than 1.3 microns.

Abstract: A circlet is defined as a compact angle representation expressing, at a given pixel comprised in the first image, the direction of change of pixel intensity. A method of locating a feature of interest includes the steps of: acquiring a first image of a feature of interest to a user; generating a learned circlet image from the first image; saving one or more sets of learned circlets corresponding to one or more selected probes; acquiring a second image of the feature of interest; generating a target circlet image from the second image; and correlating the learned circlet image and the target circlet image.

Abstract: The a surface of an object is illuminated in sequence with a number of light beams, each of which is nearly tangential to the surface. Images of the surface are recorded for each light beam, and the images are analyzed to identify features such as depressions in the surface.

Abstract: According to one of the preferred embodiments, the invention includes a machine vision system 110 for inspecting a moving object. The machine vision system 110 includes a camera subsystem 30 to capture the image of a moving object when the object moves into a viewing area, a lighting subsystem 12 to illuminate the moving object, and a controller 14 to control the camera subsystem and the lighting subsystem to effectively freeze and inspect the reflectance of the illumination by the moving object. The lighting subsystem includes light sources 16 arranged around the viewing area.

Abstract: Multiwavelength interferometric images have the phase and/or frequency of the illuminating light corrected by statistically analyzing the data, and adjusting the phase and/or frequency until a statistical measure reaches a criterion.

Abstract: An off axis paraboloid mirror is used to provide object illumination in an interferometric imaging system. The light from an object illumination light source diverges from a point apart from the focus point of the paraboloid, proceeds to the parabolic mirror surface, and is reflected as a nearly parallel beam to illuminate the object.

Abstract: A vibration isolation platform having supports such as air pistons to damp out low frequency vibrations is equipped with a means for restricting pitch and roll motion as the weight distribution is changed and the vibration isolation platform exhibits vertical motion. The preferred means for restricting are torsion bars and tension means which transfer force from one part of the platform to the other.

Abstract: A method of combining holograms or phase images of an object is disclosed, where attributes of the data used to record two phase images of overlapping portions of the surface of an object are compared and used to match pixels of the two recordings. A relative tilt angle and direction correction is added, and a third phase image is generated. Phase images of objects which are too large to be imaged in an interferometric imaging system can thus be produced.

Abstract: An interferometry method using a laser of nominally fixed—but unknown and changing—frequency and phase angle, for example, attributable to laser drift. The interference pattern is periodically sampled at a frequency considerably higher than the phase shift of the object. The wavelength is reconstructed from the sampled patterns using a correlation algorithm. The phase angle is determined using an n-bucket algorithm. After all of the complex information has been determined at all of the multiple wavelengths, the surface of the object is calculated using conventional interferometry techniques. Accordingly, laser drift—typically considered a negative attribute—is used positively.

Abstract: An optical fiber is used to deliver a reference beam in an interferometric imaging system having an off-axis paraboloid collimating and imaging mirror. A controllable fiber optic beam splitter controls the ratio of light from an optical fiber delivered to an object illumination beam and to the reference beam.

Abstract: A method of combining holograms or phase images of an object is disclosed, where attributes of the data used to record two phase images of overlapping portions of the surface of an object are compared and used to match pixels of the two recordings. A relative tilt angle and direction correction is added, and a third phase image is generated. Phase images of objects which are too large to be imaged in an interferometric imaging system can thus be produced.

Abstract: Multiwavelength interferometric images have the phase and/or frequency of the illuminating light corrected by statistically analyzing the data, and adjusting the phase and/or frequency until a statistical measure reaches a criterion.

Abstract: A tunable extended cavity laser is disclosed having a single flexure pivot or hinge forming a pivot axis about which a grating tuning element is rotated. The pivot axis does not move appreciably as the grating is pivoted. The most preferred embodiment of the flexure hinge is a cartwheel hinge.

Abstract: A tunable extended cavity laser is disclosed having a single flexure pivot or hinge forming a pivot axis about which a grating tuning element is rotated. The pivot axis does not move appreciably as the grating is pivoted. The most preferred embodiment of the flexure hinge is a cartwheel hinge.