Abstract: Systems and methods for measuring a distance from a reference plane of an optical measurement instrument to a reference plane of an optical device under test are disclose. In one embodiment a system for measuring this distance includes an illumination system, an optical system, and optical sensor and a processor. The illumination system is configured or adapted to illuminate the object under test. The optical system is configured or adapted to receive light from the object under test and to produce an aberrated image. The optical sensor is configured or adapted to receive and sense the aberrated image. The processor determines the distance from the reference plane of the optical measurement instrument to the reference plane of the optical device based on an aspect of the aberrated image sensed by the optical sensor.

Abstract: A system and method of wavefront sensing with a Shack-Hartmann wavefront sensor precisely locates focal spots on a detector array, and determines the location of the lenslet array with respect to the detector array.

Abstract: A system and method of wavefront sensing with a Shack-Hartmann wavefront sensor precisely locates focal spots on a detector array, and determines the location of the lenslet array with respect to the detector array.

Abstract: A system and method of wavefront sensing with a Shack-Hartmann wavefront sensor precisely locates focal spots on a detector array, and determines the location of the lenslet array with respect to the detector array.

Abstract: A real-time refractory control system includes a laser refractive surgery instrument for modifying the refraction of the eye, an objective diagnostic apparatus for measuring the refraction and aberrations of the eye, and an aperture-sharing element to inject a refractive surgery beam and a monitoring diagnostic beam. An associated method of adjusting a refraction of an eye, includes: performing a procedure to modify the refraction of the eye; while the procedure is being performed, measuring the refraction and/or an aberration of the eye; and terminating the procedure when a change in the measured refraction and/or the measured aberration reaches a desired value.

Abstract: An optical element which controls both the phase and irradiance distribution, thereby completely specifying the E-field, of light, allowing completely arbitrary control of the light at any plane. Such an optical element includes a portion that controls the phase and a portion that controls the irradiance. The portion that controls the irradiance is an apodized irradiance mask having its transmission varying with position in a controlled fashion. This apodized irradiance mask is preferably a pattern of metal. In order to insure a smoothly varying pattern of metal with minimized diffraction effects, a very thin mask spaced from a substrate is used to provide the metal on the substrate. The apodized irradiance mask may be placed directly on the phase control portion, or may be on an opposite side of a substrate of the phase controlled portion.

Abstract: An enhanced dynamic range wavefront sensing system includes a light source disposed on a first side of an optically transmissive device, a wavefront sensor disposed on a second side of an optically transmissive device, a relay imaging system disposed between the optically transmissive device and the wavefront sensor, and means for adjusting a distance between the light source and the optically transmissive device. Beneficially, the relay imaging system includes a range-limiting aperture to insure that the wavefront sensor never goes out of range so that a feedback system can be employed to move the light source one focal length away from the optically transmissive device.

Abstract: An improved method of high pass filtering a data set includes flattening the data set and then filtering the flattened data set with an adaptive filter. The data set is flattened by fitting it to a predetermined function, and then obtaining the difference between the original data set and the fitted data set. Beneficially, the predetermined function is a polynomial. The adaptive filter includes a masking function that has a constant, non-zero value (e.g., 1) within the bounds of the original data set and value of zero outside the bounds of the original data set.

Abstract: An optical element which controls both the phase and irradiance distribution, thereby completely specifying the E-field, of light, allowing completely arbitrary control of the light at any plane. Such an optical element includes a portion that controls the phase and a portion that controls the irradiance. The portion that controls the irradiance is an apodized irradiance mask having its transmission varying with position in a controlled fashion. This apodized irradiance mask is preferably a pattern of metal. In order to insure a smoothly varying pattern of metal with minimized diffraction effects, a very thin mask spaced from a substrate is used to provide the metal on the substrate. The apodized irradiance mask may be placed directly on the phase control portion, or may be on an opposite side of a substrate of the phase controlled portion.

Abstract: A method of measuring aberrations of a three-dimensional structure of an optical system, such as an eye, includes creating a plurality of light beams, optically imaging the light beams and projecting the light beams onto different locations in an optical system, receiving scattered light from each of the locations, and detecting individual wavefronts of the scattered light. The plurality of light beams may be created and projected simultaneously or sequentially. A system for measuring aberrations of a three-dimensional structure of an optical system includes a light source creating a plurality of light beams, an optical imaging system optically imaging the light beams and projecting the light beams onto different locations in the target optical system, and a wavefront sensor receiving scattered light from each of the locations and detecting individual wavefronts of the scattered light.

Abstract: A metrology system and method uses pulsed light to allow continuous movement of a target relative to the sensor. A metrology system and method uses dynamic adjustment of tilt in a system. A metrology system and method calibrates the system to remove inherent optical aberrations in the system. Filtering may also be used in the system to increase accuracy.

Abstract: A method for computing the visual performance of a human or animal subject based on objective measurements of visual refraction, including higher order aberrations, includes measuring wavefront aberrations of a subject ocular pupil, computing a point-spread-function from the measured pupil aberration, providing a test image, and convolving the test image with the point-spread-function. A simulated image may be produced from the convolution result of the test image with the point-spread-function. One or more specific terms of the point-spread-function may be subtracted therefrom prior to the convolving step to simulate an effect of a correcting means, such as spectacles lenses, contact lenses, or laser surgery. A best correction for a given subject may be determined by adjusting the terms that are subtracted to optimize the resultant image.

Abstract: An ophthalmic error measurement system includes a projecting optical system delivering light onto a retina of an eye, a pre-correction system which compensates a light beam to be injected into the eye for aberrations in the eye, the pre-correction system being positioned in between the projecting optical system and the eye, an imaging system which collects light scattered by the retina, and a detector receiving light returned by the retina from the imaging system. Use of the pre-correction system allows the end-to-end aberrations of the ocular system to be analyzed. The use of a pre-correction system also allows use of a minimized spot size on the retina, and all of its attendant advantages.

Abstract: Metrology is performed using short, temporally resolved measurements in order to “freeze” the deformation of the object at a particular instant in time. The pulsed light beams are used to conduct metrology of moving objects and objects which are moved relative to the detector for measurement thereof. The motion may be translational, spiral and/or rotational. The duty cycle of the light source may be varied to in accordance with the control of the operation of the detector to perform metrology using a reduced total exposure of an object, while increasing the amount of light available for the measurement.

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 Shack-Hartmann wavefront sensor having an aperture which is smaller than the size of an object being measured is used to measure the wavefront for the entire object. The wavefront sensor and the object are translated relative to one another to measure the wavefronts at a plurality of subregions of the object. The measured wavefronts are then stitched together to form a wavefront of the object. The subregions may overlap in at least one dimensions. A reference surface may be provided to calibrate the wavefront sensor.

Abstract: A rigid mount and method of mounting for a wavefront sensor. A wavefront dissector, such as a lenslet array, is rigidly mounted at a fixed distance relative to an imager, such as a CCD camera, without need for a relay imaging lens therebetween.

Abstract: An apparatus and method for characterizing a pulsed energy beam with a two-dimensional wavefront sensor. The data acquisition is synchronized with the output of the beam from the pulsed source, so that a beam characterization, including phase, can be determined in a single pulse.