Abstract: A transmission mask or coded aperture is used in spectroscopy to compressively sample an optical signal The locations of transmissive and opaque elements of the mask are determined by a transmission function The optical signal transmitted by the mask is detected at each sensor of a plurality of sensors dispersed spatially with respect to the mask A number of estimated optical signal values is calculated from sensor measurements and the transmission function The optical signal is compressed by selecting the transmission function so that the number of measurements is less than the number of estimated optical signal values A reconstructed optical signal is further calculated using signal inference An imaging system created from plurality of encoded subimaging systems compressively samples an optical signal Encoding methods include but are not limited to pixel shift coding, birefringent shift coding, transmission mask coding, micro-optic coding, diffractive coding, interferometric coding, and focal plane coding

Abstract: There is provided a binocular device, including a rigid mechanical body supporting two image sources ( 2, 4 ), one for each eye ( 6, 8 ) and two lensing devices ( 12, 14 ), one for each eye, the lensing devices having a first surface adjacent to the image sources and an opposite, second surface, each of the lensing devices projecting an image ( 16, 18 ) of one image source onto an infinite focal plane, and electronic means permitting modification of an image generated to an eye for adjusting the binocular alignment of the images. A method for aligning a binocular device is also provided.

Abstract: A hybrid optical component that collects and concentrates incident light. The hybrid component (l) includes both refractive (4) and reflective (6) elements. In preferred embodiments, refractive and reflective components focus rays on a common focal plane (2) generally located at the bottom of the reflector (6) where they are absorbed by a device such as a photovoltaic (solar) cell. Additionally, the optical component combines both imaging and non-imaging optical elements into a single device, for improved overall performance.

Abstract: A rigorous sensor model for the georeferencing of imagery from CCD linear array sensors with along-track stereo viewing is presented. The model is based on the classical collinearity equations, which are extended for the specific characteristics of the acquisition of CCD linear scanners. It includes the sensor position and attitude modeling with second-order piecewise polynomials depending on the acquisition time and a self-calibration for the correction of radial and decentering lens distortions, principal point(s) displacement, focal length(s) variation and CCD line(s) rotation in the focal plane. Using well-distributed GCPs and, additionally, Tie Points (TPs), the external orientation and self-calibration parameters, together with the TPs ground coordinates, are estimated in a least-square adjustment. In order to demonstrate the flexibility of the model, stereo images from pushbroom sensors with different characteristics have been oriented with sub-pixel accuracy in the checkpoints. The results are presented and discussed.

Abstract: A method and a system for generating image content. The method and system allow segments of a panoramic scene, to be generated with reduced distortion. The method and system reduce the amount of distortion by mapping pixel data onto a pseudo camera focal plane which is provided substantially perpendicularly to the focal location of the camera that captured the image. A camera arrangement can implement the method and system.

Abstract: Using an l = 1 blazed fork-hologram at the focal plane of the Asiago 122 cm telescope, we obtained optical vortices from the stellar system Rasalgethi (alpha Herculis) and from the single star Arcturus (alpha Bootis). We have analyzed the structure of the optical vortices obtained from non-monochromatic starlight under very poor seeing conditions using a fast CCD camera to obtain speckle patterns and carry out the lucky imaging technique, alternative to adaptive optics. With the insertion of a red filter and of a Lyot stop we performed l = 1 optical vortex coronography the double star HD74010. The results are in agreement with theory and numerical simulations. Our results open the way to applications of optical vortices to ground based astronomical observations, in particular for coronagraphy with l > 1 masks. No intrinsic orbital angular momentum was detected in the starlight.

Abstract: We explore the transition from order to chaos for the Bohmian trajectories of a simple quantum system corresponding to the superposition of three stationary states in a 2D harmonic well with incommensurable frequencies. We study in particular the role of nodal points in the transition to chaos. Our main findings are (a) a proof of the existence of bounded domains in configuration space which are devoid of nodal points, (b) an analytical construction of formal series representing regular orbits in the central domain as well as a numerical investigation of its limits of applicability, (c) a detailed exploration of the phase-space structure near the nodal point. In this exploration we use an adiabatic approximation and we draw the flow chart in a moving frame of reference centered at the nodal point. We demonstrate the existence of a saddle point (called X-point) in the vicinity of the nodal point which plays a key role in the manifestation of exponential sensitivity of the orbits. One of the invariant manifolds of the X-point continues as a spiral terminating at the nodal point. We find cases of Hopf bifurcation at the nodal point and explore the associated phase space structure of the nodal point—X-point complex. We finally demonstrate the mechanism by which this complex generates chaos. Numerical examples of this mechanism are given for particular chaotic orbits, and a comparison is made with previous related works in the literature.

Abstract: A microscope including an objective which images a sample along a microscope beam path, and an autofocus device, which is coupled into the microscope beam path via a beam splitter at a location behind the objective direction, a A light modulator for generating a two-dimensional, intensity-modulated modulation object, is located in the autofocus beam path in a plane conjugated to the focal plane of the objective or intersects the latter and is imaged into the focal plane of the objective A camera records a two-dimensional image onto which the modulation object's image is imaged The image plane of the camera intersects a plane that is conjugated to the modulation object or is located in the plane and the camera detecting the contrast of the modulation object's image located in the sample

Abstract: To detect whether a substrate is in a focal plane of a scatterometer, a cross-sectional area of radiation above a certain intensity value is detected both in front of and behind a back focal plane of the optical system of the scatterometer. The detection positions in front of and behind the back focal plane should desirably be equidistant from the back focal plane along the path of the radiation redirected from the substrate so that a simple comparison may determine whether the substrate is in the focal plane of the scatterometer.

Abstract: The k points that optimally represent a distribution (usually in terms of a squared error loss) are called the k principal points. This paper presents a computationally intensive method that automatically determines the principal points of a parametric distribution. Cluster means from the k-means algorithm are nonparametric estimators of principal points. A parametric k-means approach is introduced for estimating principal points by running the k-means algorithm on a very large simulated data set from a distribution whose parameters are estimated using maximum likelihood. Theoretical and simulation results are presented comparing the parametric k-means algorithm to the usual k-means algorithm and an example on determining sizes of gas masks is used to illustrate the parametric k-means algorithm.

Abstract: A multi-fiber connector module for optical communications is provided that receives collimated beams of light from a transceiver module and focuses the collimated beams to respective focal points that coincide with the ends of respective transmit fibers. Because the inputs to the connector module are collimated light beams, movements of one or more parts of the connector and/or transceiver module will not result in optical losses as long as the movements are not so great as to prevent the collimated light beams from falling fully on the lenses of the optics system of the connector module. The lenses then focus the collimated light beams onto the ends of the transmit fibers.

Abstract: Computer simulations of nanofocusing by elliptical mirrors are presented wherein the diffraction and propagation of coherent hard x rays are predicted using wave-optical calculations. Surface height data acquired via microstitching interferometry were used to calculate the complex pupil function of a mirror, taking into account the Fresnel reflectivity and treating the surface topography as an aberration to a perfect elliptical mirror. The reflected wave-field amplitude and phase downstream of the mirror were obtained by numerically evaluating the Fresnel-Kirchhoff diffraction integral. Simulated intensity profiles and contours (isophotes) around the focal plane are presented for coherent illumination by a 15 keV point source, which indicate nearly diffraction-limited focusing at the 40 nm level. The effect of high spatial frequency microroughness on nanofocusing was investigated by low-pass filtering the Fourier spectrum of the residual height profile. Simulations using the filtered metrology data confirmed that roughness length scales shorter than 0.1 mm have a minor effect on the focal spot size and intensity.

Abstract: A novel technique for focal-length measurements with a circular Dammann grating is presented. In the back focal plane of the lens under test, a one-order circular Dammann grating with limited aperture will produce double-humped radial rings. The separation between the two lobes varies with the displacement of the observed plane from the focal plane of the lens. By searching for the position at which the separation is minimal, the focal point of the lens can be located and hence the back focal length can be determined. Experimental results demonstrated that this method is efficient and can be used effectively for a quick check of focal length.

Abstract: A microscope assembly (102) includes an illumination source (104) coupled to an optical assembly by a coupler (132). The optical assembly includes an objective with optics that move along an optic axis. The illumination source (104) generates a light blade (106) that illuminates a portion of a sample (136) at an illumination plane (110). The light blade (106) induces a fluorescent emission from the sample (136) that is projected through the objective optics to a detector (126). The focal plane (122) of the objective optics is fixed with respect to the illumination source (104) by the coupler (132) so that the illumination plane (110) is coincident with the focal plane (122) as the objective optics move along the optic axis (124). The objective and illumination may be rapidly scanned along the optic axis to provide rapid three-dimensional imaging while the objective and illumination may also be rapidly scanned along the optic axis (124) to provide rapid three-dimensional imaging.

Abstract: The invention relates to a monostatic laser radar device for metrology and tri-dimensional colour vision, comprising a transmitter (210, 700, 400, 610, 550) for three unimodal scanning laser beams, which, by means of an achromatic doublet (700) and a scanning camera (500), focusses the beams exiting from three independent unimodal optical fibres upon the target to be probed, located at a distance dB from a nodal point M of the scanning camera; an incoherent receiver (550, 610, 620, 200, 260) which receives the radiation reflected from the target through the same scanning camera (550) and selectively focusses the received signals upon three multimodal fibres that forward them to suitable photodetectors; and an electronic apparatus that processes said signals; the launching points from the fibres and the receiving points upon the fibres being located on conjugated optical planes, the transmitter and the receiver having a common optical axis, the relationship between the interaxial distance d of the launching fibres and the interaxial distance D of the receiving fibres being expressed by d = D FD/FR, wherein FD represents the focal length of the transmitter and FR represents the focal length of the receiver.

Abstract: A convex lens using room temperature vulcanization (RTV) silicone rubber, whose acoustic impedance matches well with that of water, is a typical acoustic lens However, some considerations are required to reduce the thickness of the lens because attenuation is very large in the RTV silicone rubber Therefore, we have proposed a phase continuous Fresnel lens, which has some devices to keep the phase continuous in the entire lens aperture without an unequal phase on the exit side This lens is fabricated by removing its thickness in a staircase shape in which the difference between each step is an integer multiple of wavelength In this study, the sound fields focused by the phase continuous Fresnel lens are analyzed using a finite difference time domain (FDTD) method Using a two-dimensional (2-D) FDTD method, we surveyed the sound pressure field of the focal region by changing the burst pulse length, angle of incidence, and frequency Results show that the lens gain of the phase continuous Fresnel lens is greater than that of the convex lens, that focusing characteristics depend on the burst pulse length of sound source signal, and also that focal points strongly depend on frequency In another analysis using a three-dimensional FDTD method, we found that the main lobe is the same as that indicated by 2-D analysis results and that the level outer of the main lobe is lower than that in the 2-D analysis results

Abstract: We compare and contrast the Korsch (1972) full-field three-mirror anastigmat telescope (TMA) to the Korsch (1977) annular-field TMA. Both TMAs offer flat fields with comparably good aberration correction and comparably good telephoto advantage. Both offer good accessibility of the focal plane. The advantages of the FFTMA are its extremely uniform focal length over its field, its nearly telecentric final focus, and the fact that there is no hole in the center of its field. The advantages of the AFTMA are its complete accessible cold stop (essential if a warm telescope is to be used to image the sky at near-IR wavelengths) and its low sensitivity to mirror location error. Either alternative can deliver diffraction-limited visible-wavelength images over a one degree diameter field with a two meter aperture.

Abstract: Fluorescent nanobeads with a diameter of 20nm were used to map the three-dimensional point spread function in the near-focus region of a confocal microscope at high spatial resolution. Fluorescence images were taken in 109 equidistant planes (50nm apart) parallel to the focal plane; postacquisition stacking of these images allows the reconstruction of the point spread function in the axial plane. The experimental distribution is compared to theoretical calculations based on an integral representation for the light intensity in the focus region that takes into account stratified media, polarization, the Gaussian illumination profile, and the finite exit pinhole size.

Abstract: The spatial correlation properties in the geometrical focal region of a converging, partially coherent vortex wave field are analyzed. Expressions are derived for a pair of points on the axis of symmetry and for a pair of points in the focal plane. It is found that the longitudinal and transverse coherence lengths in the focal region change with the variation of the topological charge and the normalized coherence length of the vortex field. In addition, the degree of coherence is shown to possess phase singularities.

Abstract: Depolarization lidars are widely used to study clouds and aerosols because of their ability to discriminate between spherical particles and particles of irregular shape. Depolarization of cloud backscattered radiation can be caused also by multiple scattering events. One of the ways to gain information about particle parameters in the presence of strong multiple scattering is the measurement of radial and azimuthal dependence of the polarization patterns in the focal plane of receiver. We present an algorithm for the calculation of corresponding polarized patterns in the frame of double scattering approximation. Computations are performed for various receiver field of views, for different parameters of the scattering geometry, e.g., cloud base and sounding depth, as well as for different values of cloud particle size and refractive index. As the spatial distribution of cross-polarized radiation is of cross shape and rotated at 45° with respect to laser polarization, the use of a properly oriented cross-shaped mask in the receiver focal plane allows the removal of a significant portion of the depolarized component of the backscattered radiation produced by double scattering. This has been verified experimentally based on cloud depolarization measurements performed at different orientations of the cross-shaped mask. Results obtained from measurements are in agreement with model predictions.

Abstract: A single-axis illumination system for a multiple-axis imaging system, particularly an array microscope. A single-axis illumination system is used to trans-illuminate an object viewed with an array of imaging elements having multiple respective axes. The numerical apertures of the imaging elements are preferably matched to the numerical aperture of the illumination system. For Kohler illumination, the light source is placed effectively at the front focal plane of the illumination system. For critical illumination, the light source is effectively imaged onto the object plane of the imaging system. For dark field illumination, an annular light source is effectively provided. For phase contrast microscopy, an annular phase mask is placed effectively at the back focal plane of the objective lens of the imaging system and a corresponding annular amplitude mask is provided effectively at the light source. For Hoffman modulation contrast microscopy, an amplitude mask is placed effectively at the back focal plane of the objective lens of the imaging system and a slit is provided at a source of light of the illumination system. Structured illumination and interferometry, and a secondary source, may also be used with trans-illumination methods and apparatus according to the present invention.

Abstract: A multifunction detector for detecting energy reflected from the surface, the detector comprising: a focal plane array in communication with the optical receiving path; and an optical receiving path; a read-only integrated circuit in communication with the optical receiving path, integrated with a focal plane array; and a processor programmed to operate the focal plane array and read-out integrated circuit in a first mode to process signals in a first frequency band, and in a second mode to process signals in a second, wider frequency band.

Abstract: Synthetic aperture imaging is a technique that projects images of a scene from different views on to a virtual focal surface, enabling us to "see through" occlusions in the scene. Using a 100-camera array we have used synthetic aperture imaging to view objects concealed behind dense foliage and to track a person moving through a crowd. The ability to see through occlusions makes synthetic aperture imaging a potentially powerful tool for surveillance. This work makes two contributions. First, we characterize the image warps required for synthetic aperture imaging using projective geometry. This analysis leads to a robust camera calibration procedure for synthetic aperture imaging. Our analysis also shows the relation between the geometric complexity of the image warps and camera/focal plane configurations. In particular, we show that we can vary the focus through families of frontoparallel and tilted focal planes by simply shifting and adding the camera images. As image shifts are relatively simple to realize in hardware, this leads to a real-time system, which we demonstrate for tracking a person moving through a crowd. Second, we explore methods to achieve sharp focus at every pixel in the synthetic aperture image by reconstructing the 3D surfaces of the occluded objects we wish to see. We compare classical shape from stereo with shape from synthetic aperture focus, and describe variants of stereo that improves image contrast by deleting some of the light rays that are incident on the occluder.

Abstract: In an optical inspection tool, an image of an object under inspection, such as a semiconductor wafer, may be obtained using imaging optics defining a focal plane. Light comprising the image can be detected using multiple detectors which each register a portion of the image. The image of the object at the focal plane can be split into two, three, or more parts by mirrors or other suitable reflecting elements positioned tangent to the focal plane and/or with at least some portion at the focal plane with additional portions past the focal plane so that the focal plane lies between the imaging optics and the splitting apparatus. In some embodiments, reflective planes may be arranged to direct different portions to different detectors. Some reflective planes may be separated by a gap so that some portions of the light are directed while some portions pass through the gap. Other splitting elements may comprise a group of transmissive and reflective areas interspersed in an element positioned at or in the focal plane, with some portions of the light are reflected to detectors while other portions pass through the element(s) to other detectors. Splitting apparatuses and elements may be cascaded.

Abstract: A focusing apparatus for use with an optical system having a high NA objective lens includes an image forming and capturing mechanism for forming an image in an intermediate image zone and for capturing an image by receiving and refocusing light from a selected focal plane within the intermediate image zone, and a focus adjusting mechanism for adjusting the position of the selected focal plane within the intermediate image zone. The image forming and capturing mechanism includes at least one high NA lens. In use, spherical aberration introduced by the high NA objective lens is reduced.

Abstract: A phase contrast electron microscope has an objective with a back focal plane, a first diffraction lens, which images the back focal plane of the objective magnified into a diffraction intermediate image plane, a second diffraction lens whose principal plane is mounted in the proximity of the diffraction intermediate image plane and a phase-shifting element which is mounted in or in the proximity of the diffraction intermediate image plane Also, a phase contrast electron microscope has an objective having a back focal plane, a first diffraction lens, a first phase-shifting element and a second phase-shifting element which is mounted in or in the proximity of the diffraction intermediate image plane The first diffraction lens images the back focal plane of the objective magnified into a diffraction intermediate image plane and the first phase-shifting element is mounted in the back focal plane of the objective