Abstract: Apparatuses and methods for improving aberration determination capabilities, providing corrective prescription verification, and allowing binocular vision correction in ophthalmic wavefront measuring devices. (1) Improved aberration determination capabilities are achieved through input beam modification which includes sensing an image in a wavefront emanating from an eye in response to an input beam with a sensor and then modifying the input beam with an adaptive optical device based on the sensed information. (2) Corrective prescription verification includes modifying an image with an adaptive optical element to produce a corrected image at the patients eye. (3) Binocular vision correction for a pair of eyes includes measuring the aberrations of one eye with a first ophthalmic wavefront measuring device and measuring the aberration produced by the other eye with a second ophthalmic wavefront measuring device substantially simultaneously.

Abstract: A method and apparatus for producing a scintillation-immune adaptive optics reconstructor is disclosed. The present invention includes a wavefront sensor (70) which determines illumination slope and amplitude of a number of subapertures (75). The slope and amplitude information is coupled to a slope weighting function (90), which weights the slopes of each subaperture (75) according to the amplitude of illumination of each subaperture. The present invention determines the variation in light amplitude received by the subapertures (75) and determines a slope of the light amplitude variation. The signal gain of the imaging system is then adjusted depending on the slope of the light amplitude variation, thereby yielding a closed-loop system that compensates for amplitude disturbances caused by scintillations in the images received by the imaging system (10).

Abstract: A beam control system and method which utilizes the wavefront reversal property of nonlinear optical phase conjugation to permit incorporation of a liquid crystal OPA within the low power legs of the beam control system, thereby affording the advantages of the OPA without the power limitations thereof. The invention is adapted for use with a beacon for illuminating a target with a first beam of electromagnetic energy. The system includes a telescope (1010) for receiving a target return comprising a reflection of the first beam from the target. An optical phased array (1050) is included for correcting for aberrations in the wavefront of the target return. A mechanism is included for ascertaining the correction applied by the optical phased array to the target return. The mechanism applies the correction to a third beam which ultimately is the output beam.

Abstract: Method and apparatus to enable detection of a position of an article, and thereby enable maintenance of a desired position thereof. The apparatus includes an illumination unit, focusing optics and a focus detection unit, the focusing optics serving to direct incident light toward the article and directing light returned from an illuminated elongated region on the article toward the focus detection unit. The focus detection unit includes an optical system that collects the returned light passed through the focusing optics and creates at least two images in the form of at least two interference patterns, respectively, on the sensing surface of a detector. The first interference pattern is created by interference of light components of the collected light that propagated within a first periphery region of an optical axis of the focusing optics and light components of the collected light that propagated within a paraxial region of the optical axis.

Abstract: A phase diversity wavefront correction system for use in a multiple aperture optical imaging system forms an in-focus image as a composite, focused image from the multiple apertures of the system and also forms an additional image which is deliberately made out of focus to a known extent. Taken together, the two images are processed to create one or more metrics, such as the power metric and sharpness metric. Neural networks are provided, each having an output corresponding to a parameter of an aperture of the imaging system, such as a piston position (axial displacement) or tip/tilt (angular displacement) of one telescope with respect to the others in the system.

Abstract: A two-dimensional array of lateral-effect detectors (or position-sensing devices) is used to simultaneously measure multi-point centroidal locations at high speed. It is one of the primary components of a high-speed optical wavefront sensor design comprising a Shack-Hartmann-type lenslet array and associated analog circuitry including analog-to-digital (A/D) converters, and digital micro-processors. The detector array measures the centroidal location of each incident beam emerging from the lenslet array and calculates the local wavefront slope based on the beam deviations from their respective subaperture centers. The wavefront sensor is designed for high temporal bandwidth operation and is ideally suited for applications such as laser-beam propagation through boundary-layer turbulence, atmospheric turbulence, or imperfect optics. The wavefront sensor may be coupled with a deformable mirror as primary components of an adaptive optics system.

Abstract: A small,compact optical scanning system with small aperture size requirements, wide field-of-regard and minimal color dispersion characteristics. The inventive scanning system and method provides for optical beam steering over a broad spectral band and over a wide field-of-regard. The inventive system includes a novel device for receiving an input wavefront of electromagnetic energy along a first axis and refracting the wavefront as an output wavefront along a second axis. The device is a unique form of a liquid crystal array which can be electrically manipulated to change the effective refractive index of each pixel. The index of refraction of the device varies in response to an applied voltage. The voltage is supplied by a microprocessor and/or a servo-control system. By changing the index, the incident phase front can be steered at an angle with respect to the first axis and otherwise manipulated according to the index variant pattern induced in the array.

Abstract: A phase distortion device/method has been developed to improve images. A wave source generates waves, which stimulate the reflection and/or emission of narrow-band waves from an object of interest or a nearby object. The phase distortion of the narrow-band waves is used to obtain an impulse response function, which is then used to correct an image formed by illumination waves.

Abstract: A scanning optical microscope using a wavefront converting element suffers minimum off-axis performance degradation and allows the wavefront converting element to be controlled by a simple method. Further, a pupil relay optical system is simple in arrangement or unnecessary. A laser scanning microscope includes a laser oscillator 6 and a wavefront converting element 5 for applying a desired wavefront conversion to a laser beam 15 emitted from the laser oscillator 6. An objective 7 collects a wavefront-converted approximately parallel laser beam 17 emerging from the wavefront converting element 5 onto a sample 9. A detector 29 detects signal light emitted from the sample 9. An actuator 8 scans the objective 7 along a direction perpendicular to the optical axis.

Abstract: A process for the adaptive beam control of medium-energy laser weapons for fighting electro-optical sensors and windows, wherein the behavior of the laser power reflected from a bright spot of the target and measured by a thermal image apparatus during increasing irradiation intensity is analyzed during a phase of measurement. The laser power to be emitted that will lead to the desired laser beam diameter or to the highest possible laser intensity at the target during the subsequent phase of fighting is then derived by calculation from this as well as other parameters influencing the thermal beam expansion. It is thus made possible that the laser does not always have to be operated with the maximum power, but only with the currently needed power during the phase of fighting, so that a saving is achieved in the consumption of primary laser energy. One example is explained.

Abstract: An image forming apparatus for forming an image by modulating laser light in correspondence with an image signal. A pulsewidth modulation signal is generated in correspondence with input image data. A laser drive control circuit has a photosensor PD which detects laser light emitted from a laser diode LD and generates a detection current, a resistor which generates a detection voltage corresponding to the detection current outputted from the photosensor PD, a buffer in which the generated detection voltage is inputted, an amplifier which amplifies an output from the buffer, and a constant current source and a switch to add a predetermined current to the detection current for compensation for reduction of output voltage due to offset voltages of the buffer and the amplifier. Control data for controlling maximum and minimum pulsewidths in the pulsewidth modulation signal are obtained based on the detection voltage, and generation of the pulsewidth modulation signal is controlled.

Abstract: A phase diversity wavefront correction system for use in a multiple aperture optical imaging system forms an in-focus image as a composite, focused image from the multiple apertures of the system and also forms an additional image which is deliberately made out of focus to a known extent. Taken together, the two images are processed to create one or more metrics, such as the power metric and sharpness metric. Neural networks are provided, each having an output corresponding to a parameter of an aperture of the imaging system, such as a piston position (axial displacement) or tip/tilt (angular displacement) of one telescope with respect to the others in the system.

Abstract: An adaptive dynamic wavefront sensor and corresponding method comprising a spatial light modulator and a lenslet array. A subarray of pixels of the spatial light modulator controls illumination of a lenslet of the lenslet array. The sub-array can operate as a shutter for the corresponding lenslet or to control intensity of a focus of the lenslet.

Abstract: An imaging or viewing system, which automatically compensates for bright spots, which tend to overload or saturate imaging system. The system can be used with imaging type tracking systems, viewers and various types of optical devices which heretofore have been unable to provide satisfactory performance due to saturation or overloading of an imaging device due to bright spots, i.e., laser radiation flares or sunlight. The system in accordance with the invention is configured such that reflected radiation is imaged onto a first image plane without dividing the incoming radiation into two optical paths. A digital mirror device, i.e., is disposed at the first image plane. The radiation level of each pixel in the image plane is compared with a fixed threshold on a pixel by pixel basis and used to generate a mirror drive signal that automatically reduces the reflectivity of the corresponding mirror pixel to compensate for bright spots.

Abstract: A method and apparatus for measuring a wave front aberration of a projection lens with high precision and a related calibration method. The apparatus includes: either a light source and an element producing a first point source in combination with the light source or a first point source generating part; a magnifying projection optical system projecting and magnifying a point image of the first point source projected by a test object; a detector detecting the magnified point image projected and magnified by the magnifying projection optical system; a supporting member supporting the magnifying projection optical system and the detector; a calculating part calculating a wave front aberration; and either a second point source producing element or a second point source generating part.

Abstract: A fixed size laser beam spot is used to illuminate a solar array. The beam spot size is kept constant even though the distance to the solar array may vary by a factor of 100. The focal point of the mirror emitting the beam to the array is shifted to maintain a desired beam waist so the same spot size is incident on the array. Attached to the array is a centering device to direct the beam spot to be centered on the array.

Abstract: A method for maximum power transmission through a turbulent medium using the minimum size telescope aperture. Two telescopes are both equipped with an adaptive optical system to correct the aberrations observed on the received beam, at the same time pre-compensating an outgoing laser beam for the effects of atmospheric turbulence. By iterating back and forth between the planes of the two telescopes, maximum power is transmitted between the two telescopes.

Abstract: An adaptive optics system configured as an optical phase front measurement system which provides for relatively high resolution sampling as in holographic techniques but without the need for a reference beam. The optical phase front measurement system includes one or more lenses and a spatial light modulator positioned at the focal plane of the lenses and a camera which enables the phase front to be determined from intensity snapshots. The phase front measurement system allows for relatively long range applications with relatively relaxed criteria for the coherence length of the laser beam and the Doppler shift. As such, the system is suitable for a wide variety of applications including astronomy, long range imaging, imaging through a turbulent medium, space communications, distant target illumination and laser pointing stabilization.

Abstract: A wavefront tilt measurement system for measuring the wavefront tilt of light passing through transmitting or receiving optical systems, the optical systems including a primary aperture and internal optical elements defining an optical system focal plane. A light source emits light at the optical system focal plane towards the internal optical elements such that light from the light source emerges from the primary aperture. A plurality of tilt sensors are disposed adjacent to the primary aperture to receive light emerging from the primary aperture. Each tilt sensor includes a sensor focal plane and a plurality of detector elements. Each tilt sensor generates at the focal plane a plurality of overlapping regions of zero and first order images of light emerging from the primary aperture. The measured intensity of light in the overlapping regions is used to determine the wavefront tilt of light emerging from the primary aperture.

Abstract: A method and device for measuring optical wavefront shape parameters based on line-by-line analysis of the wavefront are disclosed. The method comprises at least one step (ACQi) consisting of acquiring a wavefront line. The acquisition comprises detecting (DETi) the line for delivering an electric signal characterizing it, for example, by means of a detection module including, in particular, an array of microlenses and a sensor, the module capable of being mobile in rotation and/or in translation. The acquisition comprises a step (Tsi) for processing the signal for determining a set Ki of parameters, for example, values proportional to the wavefront phase values measured on the line. In an embodiment, the method further comprises a step (RECi) for reconstructing each wave line consisting, for example, in expressing the line phase on a base of orthogonal polynomials, then a step (RECs) for reconstructing the wavefront on the basis of the reconstructed lines.

Abstract: A dispersed Hartmann sensor includes a Hartmann lenslet in combination with a dispersive element, whereby a Hartmann spot formed by light passing through the Hartman lenslet is dispersed parallel to the phase step of the light. The shape of the blur spot can then be examined at many wavelengths. Measuring the size of a discontinuity in the wavefront of light is then performed by forming a single image of the wavefront, dispersing the image in wavelength using a combination of a Hartman lenslet and a dispersive element, and analyzing the dispersed image along a dispersion direction of the dispersed image to measure the size of the discontinuity.

Abstract: An improved wavefront sensor for characterizing phase distortions in incident light including optical elements that spatially sample the incident light and form a dispersed spot with a fringe pattern corresponding to samples of the incident light. An imaging device captures an image of the dispersed spot with said fringe pattern formed by said optical elements. And an image processor that analyzes the spectral components of the fringe pattern of a given dispersed spot to derive a measure of the local phase distortion without ambiguity in the corresponding sample of incident light. The optical elements may comprise refractive elements, diffractive elements or a combination thereof (such as a grism). The wavefront sensor may be part of an adaptive optic system (such as a large-aperture space telescope) to enable the measurement and correction of large phase steps across adjacent mirror segments of a deformable mirror.

Abstract: A defect inspection data processing system includes a client computer having an image pickup section for picking up a two-dimensional image of a to-be-inspected object to be processed in a manufacturing process, and a data transfer section for transferring data indicative of the image picked by the image pickup section. A database stores image data transferred from the client computer. The system also includes a host computer having a defect extraction section for extracting defect information from the image data stored in the database, and a good/bad judgment section for judging whether or not the to-be-inspected object is good, on the basis of the defect information extracted by the defect extraction section. The client computer is separate from the host computer and connected thereto via a communication line.

Abstract: A method and apparatus for factoring large numbers which utilizes an optoelectronic device that has a wafer at one end that contains a plurality of LEDs. Each LED is associated with at least one period pj and at least one delay dj. A clock drives the plurality of LEDs responsive to clock cycles to flash for one clock cycle at times described by the processing pj•r+dl for r≧0. The light intensity flashed by the LEDs is controlled by a filter to be proportional to log2 (pj), and a photodetector positioned at the other end of the cylinder collects the light flashed by the LEDs.

Abstract: A wide-angle zoom lens with as few as two plastic elements codes the wavefront produced by the imaging system such that the imaging system is substantially invariant to aberrations related to misfocus. Signal processing is used to decode the wavefront to form the final image. A first type of zoom lens configuration uses as few as two lens elements. In this type, image processing may be modified to take into account the positioning of the lenses.

Abstract: The wavefront sensing device consists of a light source, a binary phase mask (10), a fixed focus lens (11) and at least two finite sized spatially separated detectors (12) positioned in the plane of focus of the wavefront sensing device. The binary phase mask (10) simultaneously applies a positive bias and a negative bias to the wavefront of the incident light such that a pair of spatially separated light points are generated in the plane of focus and detected by the detectors (12). The difference in intensity between the pair of light points is representative of the aberration of the wavefront of the incident light from the ideal.

Abstract: A method for maximum power transmission through a turbulent medium using the minimum size telescope aperture. Two telescopes are both equipped with an adaptive optical system to correct the aberrations observed on the received beam, at the same time pre-compensating an outgoing laser beam for the effects of atmospheric turbulence. By iterating back and forth between the planes of the two telescopes, maximum power is transmitted between the two telescopes.

Abstract: A device for detecting a wavefront that is defined by a plurality of contiguous light beams includes an array of lenslets for isolating the individual light beams and focusing each individual light beam to a focal point in an x-y plane. The device also has a plurality of clusters which are positioned in the x-y plane, and each cluster includes a plurality of pixels that are arranged in rows aligned in an x-direction, and columns aligned in a y-direction. Additionally, each pixel of a cluster includes both a first photocell for generating an x-signal and a second photocell for generating a y-signal, respectively, in response to an illumination of the pixel by a light beam. Further, the device includes circuitry for converting the x and y signals to digital signals and then using the digital signals to determine an x-y position for the focal point of the particular light beam that is incident on the cluster.

Abstract: An imaging or viewing system, which automatically compensates for bright spots, which tend to overload or saturate imaging system. The system can be used with imaging type tracking systems, viewers and various types of optical devices which heretofore have been unable to provide satisfactory performance due to saturation or overloading of an imaging device due to bright spots, i.e., laser radiation flares or sunlight. The system in accordance with the invention is configured such that reflected radiation is imaged onto a first image plane without dividing the incoming radiation into two optical paths. A digital mirror device, i.e., is disposed at the first image plane. The radiation level of each pixel in the image plane is compared with a fixed threshold on a pixel by pixel basis and used to generate a mirror drive signal that automatically reduces the reflectivity of the corresponding mirror pixel to compensate for bright spots.

Abstract: A sensor system includes a sensor, and an optical train adjustable to provide an optical beam to the sensor from a selected line of sight that may be varied. The optical train includes a wavefront error-introducing element in the optical train, which introduces a wavefront error that is a function of the selected line of sight. There is further a rigid-body wavefront error-correcting element in the optical train. The rigid-body wavefront error-correcting element has a spatially dependent correction structure with the nature of the correction being a function of the selected line of sight. The adjustment of the optical train to the selected line of sight moves the optical beam to the appropriate location of the rigid-body wavefront error-correcting element to correct for the corresponding introduced wavefront error of the wavefront error-introducing element at that selected line of sight.

Abstract: A wavefront sensor is provided to determine characteristics of an incoming distorted energy beam, such as a tilt angle and/or a degree of focus. The sensor includes a multi-lens array, a screen, and a beam detector. The multi-lens array focuses the energy beam to a multiple focal points. The screen, positioned adjacent to the multi-lens array, has at least one aperture to allow a portion of the energy beam to pass, while blocking the remainder of the energy beam from arriving at the multi-lens array. Each aperture is aligned with a lens of the multi-lens array. The beam detector detects the resulted focal point(s) of the energy beam passing through the corresponding aperture(s) and determines the characteristics of the passing energy beam. The screen may include a central aperture to measure a local tilt angle of a segment of incoming wavefront entering a lens of the lens array.

Abstract: A beam control system and method. In an illustrative embodiment, the inventive system (500) provides a first beam of electromagnetic energy (503); samples the first beam (503) and provides a second beam (505) in response thereto; detects aberrations in the second beam (505); and corrects aberrations in the first beam (503) in response to the detected aberrations. In a specific implementation, the invention (500) includes a beam director telescope (510) having a primary mirror (516) on which a holographic optical element (518) is disposed. The holographic optical element (518) samples the output high-power beam and provides a sampled beam to a wavefront sensor (520). The wavefront sensor (520) provides signals to an adaptive optics processor (580). The adaptive optics processor (580) analyzes the sampled wavefront, detects aberrations therein and provides a correction signal to an optical phased array (550).

Abstract: A simple and inexpensive wide-angle zoom lens with as few as two plastic elements codes the wavefront that is produced by the imaging system such that the imaging system is invariant to aberrations that are related to misfocus. Signal processing is then used to decode the wavefront to form the final image. A first type of zoom lens configuration uses as few as two lens elements. In these configurations, the image processing is modified to take into account the changing point spread function (PSF) of the system. A second type of zoom lens configuration that uses more than two lenses requires no modification of the processing.

Abstract: A positional relationship of a plurality of beam spots for a multi-beam imaging apparatus is detected. The imaging apparatus including a light source, a beam splitter that divides a received beam into a plurality of beams, a deflecting system that deflects the beams to scan, and an imaging optical system that forms a plurality of scanning beam spots on a surface. According to the method, a phase filter is provided between the light source and the beam splitter. The filter is configured to divide a cross section of the beam into a plurality of areas, light fluxes passed through adjoining two areas having an optical path difference of half a wavelength. Dark lines are formed, in each beam spot, due to the phase difference of the adjoining two areas. By detecting the dark lines of respective beam spots, a positional relationship between the plurality of beam spots can be determined.

Abstract: It is the object of the present invention to provide an optical element for controlling the polarization state spatially by using a liquid crystal and a method for manufacturing the same, and to provide an optical apparatus for correcting the polarization state in conformity with a particular purpose and method for manufacturing the same. The optical element for controlling the polarization state of light spatially by modifying directions of orientation of liquid crystal molecules caused by an oriented film and the optical apparatus by the use of the optical element are described. Orientation which is realized in the aforesaid oriented film for liquid crystal molecules is controlled by light irradiation with ultraviolet light etc.

Abstract: A free space optical communication system is disclosed whereby the optics of a transmit telescope are manipulated using adaptive optics to precompensate for wave front distortion of a light beam transmitted by a transmit telescope. Wave front distortion is manifested at the receive telescope as a change in at least one characteristic of the image of the received signal such as, for example, a reduction in the amplitude of the received signal. A mirror of the transmit telescope is deformed in such a way as to reduce the wave front distortion and correspondingly increase the resulting amplitude of the received signal.

Abstract: A laser condenser 14 comprises a plurality of laser light sources 22, a reflective type spatial light modulator 38 for modulating laser light beams L in order to correct the wavefronts of the respective laser light beams L output from the laser light sources 22, and a condenser lens 40 for condensing the laser light beams L output from the reflective type spatial light modulator 38. The laser light with a wavefront aligned by the reflective type spatial light modulator 38 is condensed by the condenser lens, and thus laser light with a small focal spot and high energy density is obtained.

Abstract: A CO2 laser beam 12 is converted into a beam of uniform intensity at the position of a phase matching element 15 by an intensity converting element 14 and the phase matching element 15. Then, the uniform intensity beam irradiates a mask 17 containing an aperture variable in size via a variable-magnification projecting optical system 16. At the time of irradiation, the laser beam at the position of the phase matching element 15 is projected onto the mask 17 at a magnification factor most suited to the size of the aperture formed in the mask 17. Further, the pattern of the mask 17 is projected onto a workpiece 19. Thus, a uniform intensity distribution of the laser beam is obtained on the workpiece and high quality laser processing becomes possible.

Abstract: A free space optical communication system is disclosed whereby the optics of a receive telescope are manipulated using adaptive optics to compensate for wave front distortion of a light beam transmitted by a transmit telescope. Wave front distortion is manifested at the receive telescope as a deviation from the normal, orthogonal orientation of the wave front of the transmitted light beam relative to its line of travel. This deviation may be detected, for example, by a wave front sensor, such as a Shack-Hartman sensor, which identifies the slope, or beam tilt, of discrete sections of the transmitted beam. The optics of the receive telescope can then be deformed in such a way as to cancel the wave front distortion and correspondingly reduce the resulting distortion of the received signal.

Abstract: The present invention relates generally to an optical element (OE) which can serve as an optical analogue to digital converter (OADC) and/or an optical digital to analogue converter (ODAC), and uses therefor. The OE can be usefully employed in a variety of applications to transform analogue information present in a light wave front into digital light signals and/or to transform digital information into analogue information in the form of the physical parameters of a light wave front.

Abstract: A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

Abstract: A wavefront sensor for detecting the wavefront produced by light waves from a light source comprises optically refractory or reflective means for receiving the light waves from the light source and producing two defocused pupil images at two different locations along an optical axis. A detector is positioned at a location spaced from the two locations of the two focused pupil images for the detector means to receive and detect two equally and oppositely defocused pupil images. A computer with appropriate software processes the characteristics of the two defocused pupil images from the detector to determine the curvature of the wavefront based on the light intensities with Dirichlet's boundary conditions for the light waves received by the wavefront sensor.

Abstract: A method for real-time, robust, stable closed-loop control of two phase correction devices to compensate for both amplitude and phase fluctuations induced by light passing through a turbulent medium. Two phase correction devices, in different conjugate planes, are controlled to minimize the difference in phase of the input beam corrupted by turbulence and an ideal reference beam.

Abstract: An optical testing apparatus for measuring the transmission characteristics of a DWDM filter. A first opto-mechanical lens assembly comprises a light emitter and a first optical axis which is angularly adjustable via a spherically shaped bearing surface pivoting about a specified first fixed point. A second opto-mechanical lens assembly comprises a light collector and a second optical axis which is also angularly adjustable via a spherically shaped bearing surface pivoting about a specified second fixed point whereby the second optical axis is positioned coaxially with respect to the first optical axis. The first optical axis and the second optical axis are coaxially aligned passing through a center of the DWDM filter positioned on a platen.

Abstract: An imaging system for measuring the field variance of distorted light waves collects a set of short exposure “distorted” images of an object, and applies a field variant data processing methodology, resulting in an image estimate which approaches the diffraction limited resolution of the underlying physical imaging system as if the distorting mechanism were not present. By explicitly quantifying and compensating for the field variance of the distorting media, arbitrarily wide fields can be imaged, well beyond the prior art limits imposed by isoplanatism. One embodiment comprehensively eliminates blurring effects introduced when imaging through the earth's atmosphere.

Abstract: An imaging system for measuring the field variance of distorted light waves collects a set of short exposure “distorted” images of an object, and applies a field variant data processing methodology, resulting in an image estimate which approaches the diffraction limited resolution of the underlying physical imaging system as if the distorting mechanism were not present. By explicitly quantifying and compensating for the field variance of the distorting media, arbitrarily wide fields can be imaged, well beyond the prior art limits imposed by isoplanatism. One embodiment comprehensively eliminates blurring effects introduced when imaging through the earth's atmosphere.

Abstract: A hybrid curvature/tilt wave front sensor (50) that employs both tilt measurements and curvature measurements of the wave front of a light beam (16). The light beam (16) is split into a first path and a second path. The light beam (16) on the first path is directed to a tilt sensor (12) employing a lenslet array (24) having a plurality of lenses (26). The lenses (26) focus separate portions (32) of the wave front onto a CCD (28) that provides local intensity measurements. A computer (30) receives electrical information of the intensity of the various beam portions (32) and computes a tilt measurement based on this information. The light beam (16) on the second path is directed to a curvature sensor (14) that includes a pair of CCDs (40, 42) positioned at the same distance before and after the focal plane of a lens (52). The intensity measurement of the beam (16) at these locations is sent to the computer (30) which performs curvature measurements on the beam wave front.

Abstract: The spatial resolution of Hartmann-type sensors can be increased by moving a wavefront being sensed relative to the sensor by a non-integral number of apertures. The apertures may have a tilt on at least one side thereof. The lenslets themselves in a lenslet array may serve as the apertures or material may be provided on the lenslet array to create the apertures.

Abstract: A system and method which substantially eliminates systematic error in a centroid determination of reconstructed waveforms from images generated by an image sensor. In accordance with the invention, a predetermined wavefront error is added to an input wavefront and the wavefront is detected. The predetermined wavefront error is effective to improve centroid determination. In the illustrative embodiment, the input wavefront is passed through a random phase plate. The phase plate is an optical window in which the thickness in a z-axis varies randomly over an X/Y plane. The random phase plate acts as a low pass filter and the output of the phase plate is an aberrated wavefront. That is, the nonuniform thickness of the phase plate generates random spatial phase errors in the optical wavefront. The autocorrelation function of the phase plate is such that random phase errors in the optical wavefront will filter out spatial frequencies higher than one cycle per pixel.

Abstract: An imaging system for measuring the field variance of distorted light waves collects a set of short exposure “distorted” images of an object, and applies a field variant data processing methodology in the digital domain, resulting in an image estimate which approaches the diffraction limited resolution of the underlying physical imaging system as if the distorting mechanism were not present. By explicitly quantifying and compensating for the field variance of the distorting media, arbitrarily wide fields can be imaged, well beyond the prior art limits imposed by isoplanatism. The preferred embodiment comprehensively eliminates the blurring effects of the atmosphere for ground based telescopes, removing a serious limitation that has plagued the use of telescopes since the time of Newton.