Abstract: The invention features a displacement and dispersion measuring interferometry system having a Helium-Neon laser light source. The light source can be a Helium-Neon laser that includes an intracavity doubling crystal and an intracavity etalon to generate two harmonically related, single-frequency wavelengths at sufficient powers for interferometric dispersion measurements. Alternatively, the light source can be a single-mode Helium-Neon laser that directs a single-frequency input beam into a resonant external cavity enclosing a doubling crystal to generate two harmonically related, single-frequency wavelengths at sufficient powers for interferometric dispersion measurements. In addition to dispersion measurements, the inherent wavelength stability of the Helium-Neon source permits high-accuracy displacement measurements.

Abstract: An apparatus inserts a reference guide pin having a reference end surface into a guide pin receiving hole in an endface of a fiberoptic connector to prepare the fiberoptic connector for interferometric profiling of the endface. The reference guide pin has an end portion on which the reference end surface is located. A connector support mechanism supports the fiberoptic connector. A reference guide pin support mechanism receives the end portion to hold the reference guide pin in axial alignment with the guide pin receiving hole as one of the connector support mechanism and the reference guide pin support mechanism is moved toward the other to insert the reference guide pin into the guide pin receiving hole.

Abstract: A device and a method for exposure of visual data onto light-sensitive recording material, a light source which emits light in at least one color, and a control unit for regulating the light amount. The control unit is connected to a light measuring unit. The light measuring unit has at least two detectors, which measure at least two different spectral components of the same exposure color. The control unit and the light measuring device form a closed loop control circuit.

Abstract: Conical surfaces (and other complex surface shapes) can be interferometrically characterized using a locally spherical measurement wavefront (e.g., spherical and aspherical wavefronts). In particular, complex surface shapes are measured relative to a measurement point datum. This is achieved by varying the radius of curvature of a virtual surface corresponding to a theoretical test surface that would reflect a measurement wavefront to produce a constant optical path length difference (e.g., zero OPD) between the measurement and reference wavefronts.

Abstract: A system and method for high speed and precision measurement of the distance between at least two near contact surfaces using heterodyne interferometry is disclosed. One of the surfaces is an optically transparent element and the other surface is a substantially non-transparent element. A laser source produces an output having two superimposed orthogonally polarized beams having S and P polarization, with a frequency difference between them. The polarized beams are split into measurement and reference beams without altering the characteristics of the polarized beams. The reference beams are caused to interfere, and a reference photo detector detects the reference beams and provides a reference signal. The measurement beam strikes the object of interest at an oblique angle after passing through a glass plate having a polarization coating on the bottom surface close to the object of interest.

Abstract: The phase-shifting point diffraction interferometer (PS/PDI) was developed to address the problem of at-wavelength metrology of extreme ultraviolet (EUV) optical systems. Although extremely accurate, the fact that the PS/PDI is limited to use with coherent EUV sources, such as undulator radiation, is a drawback for its widespread use. An alternative to the PS/PDI, with relaxed coherence requirements, is lateral shearing interferometry (LSI). The use of a cross-grating, carrier-frequency configuration to characterize a large-field 4×-reduction EUV lithography optic is demonstrated. The results obtained are directly compared with PS/PDI measurements. A defocused implementation of the lateral shearing interferometer in which an image-plane filter allows both phase-shifting and Fourier wavefront recovery. The two wavefront recovery methods can be combined in a dual-domain technique providing suppression of noise added by self-interference of high-frequency components in the test-optic wavefront.

Abstract: A scanning exposure apparatus and method thereof for maintaining a desired shape of a shot area exposed on a photosensitive substrate where an angle formed by the mirrors of interferometric systems for measuring the position of a stage and/or the angle formed by the running direction of a wafer stage and a reference mark plate is changed. A reticle on a reticle minute drive stage is scanned relative to an illuminated region and a wafer on a Z&thgr;-axis drive stage is scanned relative to an exposure region in synchronization with the scanning of the reticle. Thus, a shot area SA on the wafer is exposed to light carrying a pattern image of the reticle. The angle of rotation of a mirror facing in the non-scanning direction of the Z&thgr;-axis drive stage is calculated based on measurement values of two interferometers. The angle of rotation of a mirror facing in the non-scanning direction of the reticle minute drive stage is calculated based on measurement values of two interferometers.

Abstract: A unitized fiber optic cable (10) having cables (20) with respective buffer units (30) therein. Each buffer unit (30) includes at least two optical fibers (31) generally tightly held by a buffer layer (32) for sliding contact therewith. The buffer units (30) can be stranded about a central member (22) and enclosed in a jacket (28).

Abstract: A two-beam interferometer splits an incident light in two optical paths, combines and outputs split lights together again. The two-beam interferometer generates at least one or more combined light made from two beams each having a polarization different from each other. A polarization state detector detects a variation in the polarization of the combined light generated by the two-beam interferometer. An electric circuit calculates an wavelength of the incident light based on the variation in the polarization detected by the polarization state detector. The two optical paths of the two-beam interferometer has a difference in length between a point of splitting the incident light and a point of combining the split lights, for the detection of polarization variation in the combined light by the polarization state detector. The optical path length difference between the two paths is fixed.

Abstract: A polarization imaging system and method are disclosed for measuring the magnitude and orientation of retardance in a sample. There are no moving parts and the invention is readily constructed as an imaging system that obtains polarization values at all point in a scene simultaneously. The system first takes an image that records the apparent slow axis orientation and the apparent retardance. However, the apparent retardance is indeterminate by m&lgr;, the wavelength of observation. By recording such images at two wavelengths, and taking note of both the apparent phase and the angular orientation of polarization interference in each of the two cases, the system is able to determine retardance values of 5&lgr; or more at every point without ambiguity. The actual slow axis orientation is determined as well. The determination of retardance value and axis orientation is independent for each point measured, and does not make use of spatial relationships or distributions within the sample.

Abstract: A transmission-type extrinsic Fabry-Perot interferometric optical fiber sensor and a method used for integrity monitoring of structures and measuring strain and temperature are provided. The transmission-type extrinsic Fabry-Perot interferometric optical fiber sensor includes first single-mode optical fiber and second single-mode optical fiber, laser device, and optical detector. The first single-mode optical fiber is inserted into an end of a capillary quartz-glass tube and the second single-mode optical fiber is inserted into the other end of the capillary quartz-glass tube. Air gap is formed between the first single-mode optical fiber and the second single-mode optical fiber in the capillary quartz-glass tube. Gap length of the air gap changes in response to magnitude and direction of transformation of the capillary quartz-glass tube. The laser device launches light into an end of the first single-mode optical fiber.

Abstract: The present invention provides a method and system to actively stabilize a probe, such as a microelectrode, relative to movement of the subject, utilizing laser interferometry. In the preferred embodiments, a probe is mounted on a manipulator such that the probe moveable in response to a control voltage. A laser interferometer is utilized to transmit a first light beam to the subject and to receive a reflected light beam, to modulate a second light beam with a radio frequency signal to form a reference light beam, and to combine the reflected light beam and the reference beam to form an interference pattern. A demodulator is utilized to quadrature demodulate a phase shift of a radio frequency component of the interference pattern to determine a displacement signal representative of an amount and direction of subject movement, and to convert the displacement signal to the control voltage.

Abstract: A method for determining wafer misalignment by using a pattern on a fine alignment target. In one embodiment, the method comprises a series of steps in a stepper, starting with the step of receiving a wafer having an alignment target. In another step, the wafer is aligned using the alignment target. Next, a pattern is created around the alignment target using an overlay. Then, the misalignment is determined between the alignment target and the pattern created around the alignment target.

Abstract: Production of interference patterns from incoherent light sources by using an optical filter, a field mirror, and a plane mirror. The optical filter is designed to filter incoherent light waves and generate coherent light waves. The field mirror is arranged to convert the coherent light waves into plane waves. The plane mirror is arranged as a Lloyd's mirror to generate interference patterns from the plane waves.

Abstract: A high intensity discharge lamp, especially for optical projection systems, in one embodiment uses an anode electrode, a cathode electrode and a cylindrical envelope of single crystal (SC) sapphire. The fill may contain hydrogen, chlorine, sodium, scandium, sulfur and selenium and is under pressure exceeding 20 atmospheres. The lamp produces a continuous non-flash arc and generates a correlated color temperature between 6500 and 7000 degrees Kelvin and an efficacy exceeding 60 lumens/watt.

Abstract: Width and direction of interference fringes of a two beam interference objective device can be adjusted with a single hand, thereby improving operability and work efficiency. The two beam interference objective device includes an objective lens (1), a prism (12) provided between the objective lens (1) and a sample (4), a reference mirror (13) provided to one of light-paths divided by the prism (12), and a tilting device (14) for tilting the reference mirror (13) to adjust the width and direction of the interference fringes. The tilting device (14) includes a width adjuster (41) for pivotally moving the reference mirror (13) centering an axis parallel to an optical axis of the objective lens (1) while keeping a distance from the optical axis of the objective lens (1) to the reference mirror (13), and a direction adjuster (51) for turning the reference mirror (13) centering the one of divided optical paths.

Abstract: A miniaturized chemical sensor features an optical microcavity coated with a surface layer, and a waveguide that evanescently couples light into the microcavity. The surface layer is adapted to chemically interact with one or more molecule species in a chemical vapor surrounding the microcavity, so as to alter the evanescent light coupling between the optical microcavity and the waveguide. The chemical interaction causes a change in the index of refraction of the microcavity, resulting in a measurable phase difference readout. The refractive index sensitivity is substantially increased, because of the high Q-value of the optical microcavity.

Abstract: This invention relates to a displacement information detecting apparatus which has a light beam illuminating system for making a light beam enter a first area of the grating portion of a relatively displaceable scale member provided with a grating portion having a wavefront dividing function in the direction of grating arrangement, a reflecting member for reflecting the light beam having emerged from the first area into which the light beam has been made to enter by the light beam illuminating system to enter a second area which is in a direction substantially perpendicular to the grating arrangement relative to the first area, and a plurality of light receiving portions for receiving a plurality of light beams created by the wavefront dividing function in the second area into which the light beam has been made to enter by the reflecting member, a signal corresponding to the displacement relative to the scale member being provided by the light reception by each of the light receiving portions.

Abstract: A high intensity discharge lamp constructed with a tubular envelope composed of single crystal sapphire in which a continuous non-flash arc is created across multiple electrodes to generate a radiation emitting plasma. The lamp may operate at higher temperatures and pressures than conventional high intensity discharge lamps to produce greater luminance at any given power input. The lamp fill may be chosen from a wide range of gases and additives to produce the desired light spectra in the range from ultraviolet through near infra-red. The effective life of the lamp may be significantly extended. The lamp may be utilized particular benefits in image projection where a small powerful light source is required to optically match increasingly smaller image generation devices. In particular, the lamp may maintain a pre-selected correlated color temperature from 4,000 to 9,000° K over the life of the lamp.

Abstract: Interferometric apparatus and methods for reducing the effects of coherent artifacts in interferometers. Fringe contrast in interferograms is preserved while coherent artifacts that would otherwise be present in the interferogram because of coherent superposition of unwanted radiation generated in the interferometer are suppressed. Use is made of illumination and interferogrammetric imaging architectures that generate individual interferograms of the selected characteristics of a test surface from the perspective of different off-axis locations of illumination in an interferometer and then combine them to preserve fringe contrast while at the same time arranging for artifacts to exist at different field locations so that their contribution in the combined interferogram is diluted.