Abstract:
Method and systems are presented for analysing a wavefront using a spectral wavefront analyser to extract optical phase and spectral information at a two dimensional array of sampling points across the wavefront, wherein the relative phase information between the sampling points is maintained. Methods and systems are also presented for measuring an eye by reflecting a wavefront of an eye and measuring the wavefront at a plurality of angles to provide a map of the off-axis relative wavefront curvature and aberration of the eye. The phase accuracy between wavelengths and sample points over a beam aperture offered by these methods and systems have a number of ocular applications including corneal and anterior eye tomography, high resolution retinal imaging, and wavefront analysis as a function of probe beam incident angle for determining myopia progression and for designing and testing lenses for correcting myopia.
Abstract:
A system consisting of a phase camera with microlenses placed in the focal point of a converging lens, wherein the camera data, processed using a combined Fourier “Slice” and fast Fourier transform edge detection technique, provide both a three-dimensional wavefront map and a real scene depth map within a broad range of volumes. The invention is suitable for use in any field where wavefronts need to be known such as earth-based astronomical observation, ophthalmology, etc., as well as in fields requiring metrology, e.g. real scenes, CCD polishing, automobile mechanics, etc. The invention is applied to the particular case of atmospheric tomography using ELTs (large-diameter telescopes: 50 or 100 meters).
Abstract:
A method determines power of a modulated signal that is applied to a wavelength meter by summing bin values within a designated bin range of a frequency transformed interferogram representing the modulated signal and provided by the wavelength meter. In a first embodiment of the method, the bin range within which the bin values are summed is designated by mapping a series of signal characteristics indicative of the types of the modulated signals applied to the wavelength meter, to a series of bin spans within the frequency transformed interferograms that represent the modulated signals. The method then enables a selection of a signal characteristic from the series of signal characteristics to identify the modulated signal that is applied to the wavelength meter. In response to a selection, the bin values are summed within a bin range that is consistent with the mapping of the series of signal characteristics to the series of bin spans and that is positioned about a center bin of the frequency transformed interferogram. In a second embodiment of the method, the bin range within which bin values are summed is designated automatically based on attributes of the frequency transformed interferogram.
Abstract:
Method and systems are presented for analysing a wavefront using a spectral wavefront analyser to extract optical phase and spectral information at a two dimensional array of sampling points across the wavefront, wherein the relative phase information between the sampling points is maintained. Methods and systems are also presented for measuring an eye by reflecting a wavefront of an eye and measuring the wavefront at a plurality of angles to provide a map of the off-axis relative wavefront curvature and aberration of the eye. The phase accuracy between wavelengths and sample points over a beam aperture offered by these methods and systems have a number of ocular applications including corneal and anterior eye tomography, high resolution retinal imaging, and wavefront analysis as a function of probe beam incident angle for determining myopia progression and for designing and testing lenses for correcting myopia.
Abstract:
PURPOSE: An apparatus for simultaneously measuring a refractive index and an absorption coefficient of material is provided to simply measure the refractive index and the absorption coefficient of material by using Fourier transform analysis. CONSTITUTION: A beam splitter(110) is provided to divide beam generated from a light source(100) into first and second beam paths having the same beam intensity. Beam passing through a material(120) positioned in the first beam path is reflected into a moving path by a first reflection mirror(130a). A second reflection mirror(130b) is provided to reflect beam into the moving path based on the second beam path. Beam reflected from the first and second reflection mirrors(130a,130b) is detected by a beam detector(140). A scan motor(150) is driven to scan a distance of an interferometer from the second reflection mirror(130b). A computer(160) analyzes a refractive index and an absorption coefficient of material to be measured.