Abstract: We determined the group-delay dispersion (GDD) of five microscope objectives by measuring the second-order autocorrelation at the focal points of the objectives with two-photon excited fluorescence as the power square sensor. We found that typical microscope lens systems introduce significant GDD (2000–6500 fs2). The third-order dispersion determined for these objectives limits the minimum obtainable pulse width at the focal point of an objective to 20–30 fs if not compensated. No significant chromatic aberration or higher-order dispersion effects were found for any of the optical components measured within the wavelength range of 700–780 nm and for pulse widths greater than 50–60 fs.

Abstract: It is well known that uniform illumination of a lens leads to a focal field with a pattern of dark Airy rings in the focal plane, whereas this is not the case for Gaussian illumination. We show theoretically and experimentally that in the transition between the two cases the Airy rings, being phase singularities, reorganize themselves by means of a creation–annihilation process leading to new dark rings outside the focal plane.

Abstract: An electro-optical framing camera forward motion compensation (FMC) system comprising a moving shutter and a full frame focal plane array detector is disclosed. The reconnaissance system is designed to minimize the variation of image motion from a target scene across the focal plane array. The full frame focal plane array, such as a Charge Coupled Device (CCD), is designed to transfer and add the image from pixel to pixel at a predetermined rate of image motion corresponding to the region exposed by the focal plane shutter. The focal plane shutter aperture and velocity are set to predetermined values coordinated with the available illumination. The CCD image transfer rate is set to minimize the smear effects due to image motion in the region of the scene exposed by the focal plane shutter. This rate is variable with line of sight depression angle, aircraft altitude, and aircraft velocity/altitude ratio. Further, a method of FMC utilizes a comparison of a measured light level to a standard value in order to determine the appropriate exposure time and shutter motion rate. An optimal FMC clocking signal is calculated based on image motion equations incorporated in the processing unit of the reconnaissance system.

Abstract: The present invention features two flat-field, telecentric, infinite conjugate, achromatic objectives (32 and 34) each of which has an external pupil lying in a common plane located equidistant from the two objectives, defining a mechanically accessible central pupil (30) of an imaging system centered in the common plane (28). Each of the objectives is afocal in the common plane, with one of the lenses forming a focal plane proximate to a sample. The lenses are adapted to provide varying levels of magnification while keeping constant the number of resolvable points in the field of view. An array detector (14) is positioned proximate to a focal plane formed of the remaining objective lens (34). The double objective lens assembly is described as being included in transillumination and epi-illumination systems.

Abstract: A method of processing a material with a first and a second surface (8, 9) by means of a laser beam (2), which is focused by means of a multilens objective in a number of focal points (F1, F2...Fn), which are approximately positioned on a common axis with an angle to the first surface (8). The focal points are spaced apart and used for cutting plates, several focal points being utilized for melting/cutting the plate material. As a result a good cutting notch is obtained with a poor adhering of slags and a good separation of the cut parts.

Abstract: A device and method for uniformly illuminating bar codes and two dimensional symbologies. An illumination source is mounted within the device to flood an area congruent with the field of view of the imaging optics with light to be reflected off of a code symbol. The imaging optics collects the reflected illumination received back through the window and images the same on a detector focal plane. An array of solid state light-emitting diodes are disposed adjacent to the imaging optics and a diffuser is placed between the emitters and the device window for illumination source. The emitters and diffusers are spatially arranged so as to cause homogenous distribution of light energy beyond the window and congruent with the field of view of the imaging optics.

Abstract: A monochromatic analysis of the RX nonimaging concentrators as imaging optical systems is presented (R stands for refractive, X for reflective). All of them have rotational symmetry and an image-side numerical aperture of 1.46 with the use of an index of refraction n′=1.5, which means a half-rim angle of illumination of 77 deg. This is equivalent to 95% of the theoretical limit of concentration. For an object-side focal length of f=17.1 mm (i.e., an entry aperture diameter of 50 mm) and a wavelength λ=950 nm, the RX has an equivalent passband above 32 mm-1 in a field of view of ±3.2 deg and above 19 mm-1 in a field of view of ±4.8 deg. This feature of RX concentrators allows one to use the same RX with receivers/emitters very different from the one of the design presented (in size and contour shape) with no loss of nonimaging quality. Moreover, the combination of simplicity, compactness, imaging capability, and high concentration makes the RX an exceptionally good optical device for high-sensitivity focal plane array applications.

Abstract: The arrangement includes an illumination optic (1-7). An object carrier (9,10) accommodates the examined object in the light path. A lens array (14) comprises a number of lenses of equal focus. A detector array (15) is arranged behind the lens array, in the focal plane of the single lenses of the lens array. The rotation angle of the object is supplied to the control computer (16). A non-focal optical system (12,13) is pref. arranged between the object carrier and the lens array, with its focal distance on the object side smaller than the focal distance on the detector side. The non-focal optical system consists pref. of a microscope objective arranged on the object side, and an achromic arrangement.

Abstract: We consider the conversion of a Gaussian beam into a flat-top profile by using a phase-plate which consists of a single-zone binary optic. The near- and far-field distributions are studied. We deduce the conditions required to produce super-Gaussian profiles of order 6 at the focal plane of a converging lens.

Abstract: An optical sensor system for measuring the approximate three-dimensional profile and position of an object. A reduced to practice embodiment of the optical sensor system has been used to measure the three-dimensional profile and position of an object within a range of 40 inches to 2 inches with high accuracy and high update rates (>1 KHz). The sensor system generates a set of optical beams using a projection lens and multiple light emitting diodes (LED) located in a back focal plane of the projection lens. The position of each LED determines the angle of a beam transmitted thereby. By turning on each LED sequentially in time, a set of beams is generated at various angles that illuminates the object to produce a set of spots on the object. The range from each LED to each of the spatially-separated illuminated spots on the object is determined by imaging the spots onto a two-dimensional transverse-effect photodiode. Signals derived from a pair of photocurrent outputs from the photodiode are processed to determine the positions of the spots on the two-dimensional transverse-effect photodiode. Computations are performed that implement optical triangulation to determine the range and approximate three-dimensional profile to the object.

Abstract: A system for containing either a reflective particle or a particle having an index of refraction lower than that of the surrounding media in a three-dimensional light cage. A light beam from a single source illuminates an optics system and generates a set of at least three discrete focussed beams that emanate from a single exit aperture and focus on to a focal plane located close to the particle. The set of focal spots defines a ring that surrounds the particle. The set of focussed beams creates a "light cage" and circumscribes a zone of no light within which the particle lies. The surrounding beams apply constraining forces (created by radiation pressure) to the particle, thereby containing it in a three-dimensional force field trap. A diffractive element, such as an aperture multiplexed lens, or either a Dammann grating or phase element in combination with a focusing lens, may be used to generate the beams. A zoom lens may be used to adjust the size of the light cage, permitting particles of various sizes to be captured and contained.

Abstract: A multi-aperture imaging system for continuous dwell imaging of complex extended scenes which are not required to contain localized point sources. The multi-aperture imaging system includes a plurality of subaperture telescopes, each of which collect image data of an instantaneous field of view of an extended object scene within a field of regard of the imaging system. The image data collected by each subaperture telescope is transferred by respective optical delay paths to a beam combiner which combines all the image data in coherent fashion to form a single high resolution image of said object scene at a focal plane of the beam combiner. The subaperture telescopes are optically phased using phase diversity techniques which include using a phase diversity sensor located at the focal plane of the beam combiner to detect wavefront errors in the collected images. A phase controller is used to make phase and tilt adjustments to moveable mirror in the optical delay paths of the respective subaperture telescopes to ensure that the path length travelled by the collected image data from each subaperture telescope is maintained equal. The subaperture telescopes are supported on a deployable Y-shaped framework which folds up for compact stowage within a satellite launch canister. The subaperture telescopes are spaced in a redundant array sufficient to provide a desired uniform coverage of the spatial frequencies of a modulation transfer function (MTF) of the imaging system.

Abstract: A single camera autostereoscopic video device including an array of cylindrical lenses. The device includes a single inlet objective having a single optical axis. The lens array is positioned substantially in the image focal plane of the entrance objective and has a focal length such that for an image area equal to the pitch of the lenses constituting the array, the image of the entrance pupil of the inlet objective has a nominal width equal to the pitch. The device also includes a transfer optical system and an image sensor. The transfer optical system directs the light rays which emerge from the lens array onto the image sensor. The image of the lens array in the transfer optical system being such that the pitch of the lenses of the lens array corresponds therein to an integer number of image points (pixels) of the image sensor.

Abstract: The invention relates to an optical device, especially a scanning microscope (1), wherein an expanded laser beam (2) is divided into several partial beams (4) by micro lenses (5) that are arranged next to each other. Each partial beam (4) is focused onto a focal point (11) by means of a common lens (7) in order to optically excite a sample (8). The fluorescent light emanating from the individual focal points (11) of the sample (8) is registered by a photosensor (13) placed behind the lens (7) from the sample (8) outwards. Each photon of fluorescent light coming from the sample (8) and registered by the photosensor is excited by at least two photons from the laser beam (2).

Abstract: A scheme for realizing the automatic adjustment of the electron optics system in an electron optics device such as scanning electron microscope, in which a prescribed number of images sequentially obtained by the electron optics device at sequentially adjusted focal points are stored; a moving amount of a sample image in the stored images is calculated; whether an adjustment of the electron optics system of the electron optics device is necessary or not is judged according to the calculated moving amount of the sample image; and the electron optics system of the electron optics device is adjusted according to the moving amount of the sample image when it is judged that the adjustment of the electron optics system of the electron optics device is necessary. A scheme for realizing the astigmatism correction in a charged particle beam optical system of an electron optics device such as scanning electron microscope is also disclosed.

Abstract: A study of the spectral shifts of a well-known type of partially coherent field, namely, one formed by Gaussian Schell model beams, propagating beyond an optical system reveals that there are no shifts in the geometric-image plane, whereas the greatest (blue) shift occurs in the back focal plane. These results are relevant for spectroradiometric measurements.

Abstract: For a class of rational triangular maps of a plane, characterized by the presence of points in which a component assumes the form , a new type of bifurcation is evidenced which creates loops in the boundaries of the basins of attraction. In order to explain such bifurcation mechanism, new concepts of focal point and line of focal values are defined, and their effects on the geometric behavior of the map and of its inverses are studied in detail. We prove that the creation of loops, which generally constitute the boundaries of lobes of the basins issuing from the focal points, is determined by contacts between basin boundaries and the line of focal values. A particular map is proposed for which the sequence of such contact bifurcations occurs, causing a fractalization of basin boundaries. Through the analytical and the numerical study of this example new structures of the basins of attraction are evidenced, characterized by fans of stable sets issuing from the focal points, assuming the shape of lobes and arcs, the latter created by the merging of lobes due to contacts between the basin boundaries and the critical curve LC.

Abstract: We present four methods, with different levels of sophistication and precision, for calculating the refractive power of the ocular lens from its optical structure. The first method uses finite ray tracing but simulates a paraxial ray by using small ray heights. The second method involves a recursive paraxial ray-tracing procedure. The other two methods do not depend on any ray-tracing procedure but use much simpler, approximate equations. In the third method the ray height is assumed not to change within the lens, and in the fourth method the ray path is assumed to be parabolic. The fourth method, but not the third method, can separately calculate the power of the surfaces and the gradient-index lens bulk, which are then used in the three-lens equation to calculate the power of the lens as a whole.

Abstract: A diaphragm having an aperture, the size of which is equal to or smaller than λf/p (λ is the wavelength, p is the imaging resolution, and f is the focal length of an imaging optical system) is arranged on the focal plane of the object space of the imaging optical system, and object light via the aperture is imaged by the imaging optical system. The object light via the imaging optical system and reference light are brought to interference to form interference fringes, and an image of the interference fringes is sensed. Using the hologram sensed in this manner, the image of the object to be sensed is reconstructed by adopting an imaging optical system equivalent to that upon imaging, and setting the positional relationship between the formed hologram and the imaging optical system in correspondence with that between the imaging optical system and the imaging surface upon imaging. In this way, a holography imaging apparatus which can vary the field of view and can sense a high-quality hologram using an imaging device having a relatively low spatial resolution is realized, and a holography display apparatus which can display an image by eliminating distortion with respect to the original image from a hologram sensed by the holography imaging apparatus of this invention is realized.

Abstract: Systems and methods for high efficiency illuminators are described. An illuminator includes an elliptical reflector defining a first focal point, a second focal point, a first focal plane and a second focal plane, the first focal point and the second focal point defining a principle axis; an output coupler optically coupled to the elliptical reflector, the output coupler including a first proximal end and a first distal end, the first proximal end defining an output coupler axis that is substantially coaxial with the principle axis; and a hollow conical reflector optically coupled to the output coupler, the hollow conical reflector including a first end defining an first aperture and a second end defining a second aperture, the first aperture and the second aperture defining a hollow conical reflector axis, the hollow conical reflector being positioned such that i) the hollow conical reflector axis is substantially coaxial with the principle axis and ii) a plane defined by the input aperture is substantially coincident with the second focal point, the second end of the hollow conical reflector being mechanically connected to the proximal end of the output coupler. The systems and methods provide advantages in that the efficiency of coupling between the light source and the coupler is substantially improved, albeit through an opening formed between the conical and spherical reflectors that is of smaller diameter than that of the coupler.

Abstract: Summary The term 'principal points' originated in a problem of determining 'typical' heads for the design of protection masks, as described by Flury. Two principal points in the mask example correspond to a small and a large size. Principal points are cluster means for theoretical distributions, and sample cluster means from a k -means algorithm are non-parametric estimators of principal points. This paper demonstrates that maximum likelihood estimators and semi-parametric estimators based on symmetry constraints typically perform much better than the k -means estimators. Asymptotic results on the efficiency of these estimators of two principal points for four symmetric univariate distributions are given. Simulation results are provided to examine the performance of the estimators for finite sample sizes. Finally, the different estimators of two principal points are compared using the head dimension data for the design of protection masks.

Abstract: An apparatus for three-dimensional investigation of an object including an illuminating grid located in an illumination plane and generating a plurality of points of light when illuminated by a light source; an optical imaging system that images the illuminating grid in a focal plane at the location of the object to be measured and also images light radiated from the object into a receiver plane; a receiver array with photosynthesis areas that records the light transmitted by optical imaging system and the light that is reflected in or at the object or is emitted by fluorescence; and an array of anamorphic lenses located in front of receiver array.

Abstract: A system (50) and method for converting an incoming image of a scene (12) into electronic form adapted for use with focal plane arrays of detectors (24, 28). The inventive system (50) includes a surface (30) having an electromagnetic energy transmissive region (34), a reflective region (32), and a transition region (36) that has varying reflectance. A first focal plane array (24) detects a first portion (18, 39, 43) of the incoming image (12) that is transmitted through the transmissive region and the transition region (36). A second focal plane array (28) detects a second portion of the incoming image (20, 41, 45) reflected by the reflective region (32) and the transition region (36). An image combining system (40) combines the first (43) and second portions (45) of the incoming image via an image combining algorithm and provides a combined image without a dead pixel region. In the illustrative embodiment, the incoming image (12) is focused onto the surface (30) via a first lens (22). The surface (30) is a glass surface having a coating with varying degrees of reflectance across the surface (30). In the transition region (36) the glass surface (30) changes from completely transmissive to completely reflective. The gradient of reflectance in the transition region (36) is pre-determined and varies in accordance with information in the image combining algorithm. In the specific embodiment, a second lens (26) focuses the first portion (43) of the incoming image (12) onto the first focal plane array (24). A third lens (26) focuses the second portion (45) of the incoming image (12) onto the second focal plane array. Electromagnetic energy detected by the first (24) and the second (28) focal plane arrays is converted into electronic signals that are fed to a computer (40) running software that includes the image combining algorithm. The image combining algorithm includes a correlation algorithm for maximizing image registration. The image combining system also includes a display monitor (46) for displaying a combined image.

Abstract: A scanning apparatus providing separate fixed object focal planes for transmissive and reflective original documents to be scanned, wherein a scan carriage containing illumination, sensor, and optical elements is moved together to scan an original document and to obtain a digitized representation thereof. The movable scan carriage has an illumination source disposed between the reflective and transmissive object focal planes, with the object focal plane to be used selected by changing the position of a single optical element within the scan carriage. The illumination source comprises a single lamp disposed for correct illumination of the selected object focal plane. Automatic resolution selection and focusing of the original image can occur using a converging device comprising a first and second focusing lens.

Abstract: An alignment device which may include an objective optical system for detecting the light from a first mark formed, for alignment, in a first mark area on a substrate and the light from a second mark formed, for alignment, in a second mark area, a first detection optical system having a first detection area within the viewing field of the objective optical system and adapted to detect the light from the first mark through the objective optical system, a second detection optical system having a second detection area, different from the first detection area, within the viewing field of the objective optical system and adapted to detect the light from the second mark through the objective optical system, and a focus detection system for detecting the deviation of the first mark area with respect to the focal plane of the first detection optical system and the deviation of the second mark area with respect to the focal plane of the second detection optical system, by irradiating the first and second detection areas respective with light beams and receiving the reflected lights therefrom.

Abstract: A new multiplexer/demultiplexer includes a compound focusing mechanism having adjacent focal points. Multiple images of one or more input pathways for each different wavelength signal are projected onto one or more output pathways. The resulting spectral response is flattened in the vicinity of the center wavelength of each different wavelength signal. The number and spacing of the focal points, as well as the mode field radii of the input and output pathways, can be optimized for desired combinations of channel bandwidth, insertion loss, and crosstalk.

Abstract: An imaging system for viewing indicia on an object to be observed in which the indicia comprises a plurality of either hard and/or soft marks. The light supplied by a light source is focussed by at least one lens and supplied toward an object to be observed and the reflected light is then focussed at a focal plane. The focal plane is located adjacent or coincident with a light receiving entrance of a camera or other imaging device. When a soft mark is imaged, the light is supplied at an angle to but not along the optical axis and is focussed by the lens to from an accurate image of the light source at the focal plane. Any light which contacts the unaltered specular reflective surface of the object to be observed as well as the central area of the soft mark facilitates a true and accurate reflection of the light source at the focal plane while the altered, non-flat areas of the object to be observed at least partially scatter or disperse the supplied light. Some of the scattered and dispersed light is received by the light receiving entrance and can be focussed and observed by the camera so that the indicia can be accurately perceived by the camera using conventional techniques. When imaging a hard mark, light is supplied by the light source along the optical axis. The supplied light which illuminates the hard mark is effectively absorbed by or reflected away from the optical axis and thus appears dark while the specular areas of the object to be observed are perceived by the camera as being bright.

Abstract: An image detection system (10) uses an optical configuration for both image forming and calibration phases of operation. A field lens (20) has an inner portion (36) of a conventional prescription to allow for collection of scene based energy for an opto-electronic approximation of the infrared detail within the afocal field of view by a focal plane array (32). The field lens (20) also has an outer portion (38) that collects far field energy from a scene area (AI) through a converging point (PI). The energy collected from the scene area (AI) is indicative of the average energy level within the scene. The electrical equivalent values of all energy received from the unique area (AI) is stored in a multidimensional range used for subsequent gain and offset calibration coefficient calculations.

Abstract: We have presented and demonstrated a new method for flattening the passband of PHASAR channels Input and output star couplers are designed with two focal points to produce two adjacent image points for each signal wavelength An eight-channel-200-GHz PHASAR has been fabricated with a 05-dB passband equal to half the channel spacing