Abstract: Apparatus and methods are described for calibrating an optical system that is used for measuring optical properties of a portion of a subjects body. During a calibration stage, a front surface of a calibration object (300) is illuminated, light reflected from a plurality of points on the calibration object (300) is detected, and intensities of the light reflected from the plurality of points on the calibration object (300) are measured. During a measurement stage, the portion of the subjects body is illuminated, and light reflected from the portion of the subjects body is detected. Measurements performed upon the light that was reflected from the portion of the subjects body are calibrated, using the measured intensities of the light reflected from the plurality of points on the calibration object (300). Other applications are also described.

Abstract: Systems and methods for detecting physical characteristics of a multilayered tissue of a subject, such as a tear film including analyzing received detector-output indicative of optical properties of light reflected or deflected from the respective multilayered tissue, to determine spectral properties of the multilayered tissue; and determining physical characteristics of the multilayered tissue by using multiple spectral models of the of the multilayered tissue, each model being associated with spectral properties indicative of different tissue characteristics, wherein physical characteristics of the multilayered tissue are determined by hierarchal determination of a best-fit model from the multiple spectral models.

Abstract: Apparatus and methods are described for calibrating an optical system that is used for measuring optical properties of a portion of a subjects body. During a calibration stage, a front surface of a calibration object (300) is illuminated, light reflected from a plurality of points on the calibration object (300) is detected, and intensities of the light reflected from the plurality of points on the calibration object (300) are measured. During a measurement stage, the portion of the subjects body is illuminated, and light reflected from the portion of the subjects body is detected. Measurements performed upon the light that was reflected from the portion of the subjects body are calibrated, using the measured intensities of the light reflected from the plurality of points on the calibration object (300). Other applications are also described.

Abstract: Apparatus and methods are described for performing tear film structure measurement on a tear film of an eye of a subject. A broadband light source (100) is configured to generate broadband light. A spectrometer (250) is configured to measure a spectrum of light of the broadband light that is reflected from at least one spot on the tear film, the spot having a diameter of between 100 microns and 240 microns. A computer processor (28) is coupled to the spectrometer and configured to determine a characteristic of the tear film based upon the spectrum of light measured by the spectrometer. Other applications are also described.

Abstract: Apparatus and methods are described for performing tear film structure measurement on a tear film of an eye of a subject. A broadband light source (100) is configured to generate broadband light. A spectrometer (250) is configured to measure a spectrum of light of the broadband light that is reflected from at least one spot on the tear film, the spot having a diameter of between 100 microns and 240 microns. A computer processor (28) is coupled to the spectrometer and configured to determine a characteristic of the tear film based upon the spectrum of light measured by the spectrometer. Other applications are also described.

Abstract: Apparatus and methods are described for determining the tomography and/or topography of an object. A light source generates light, and an optical element generates a 2D pattern from the light and directs the 2D pattern toward the object. An objective lens focuses the 2D pattern at an image plane, and a 2D imager acquires at least one image of the 2D pattern. The image has variable image contrast that varies according to displacement of a surface of the object from the image plane, such that maximal image contrast of the 2D pattern is achieved when the surface of the object and the image plane are coincident. A processing unit, operatively coupled to the 2D imager, derives the object's tomography and/or topography at least partially responsively to the variable image contrast of the image. Other applications are also described.

Abstract: Apparatus and methods are described, for detecting the surface topography of a portion of a curved surface of an object. A beam of light is directed toward the surface from a broad angle of incidence with respect to an optical axis of a camera. Light reflected from the surface is received by the camera, via a narrow-angle aperture. One or more darkened regions in the received light are detected, and the surface topography of portion of the surface is detected at least partially in response to the detected darkened regions. Other applications are also described.

Abstract: Apparatus and methods are described for determining tomographic and/or topographic data relating to an object. The object is illuminated with at least one wave packet from light generated by a multi-spectral light source. The wave packet is split into two split wave packets, and an optical path difference (OPD) is introduced between the two split wave packets, that is smaller than the coherence length of the wave packet. The two split wave packets are combined to generate a 2D image of the illuminated object, and the data relating to the object is determined by processing the 2D image using long coherence phase shift interferometry algorithms, by analyzing the 2D image as if the 2D image was generated using monochromatic light having a wavelength that is equal to a mean wavelength of the wave packet. Other applications are also described.

Abstract: Apparatus and methods are described including a line spectrometer that receives a point of light. The line spectrometer includes a first optical element, and a second optical element configured to convert the point of light to a line of light and to direct the line of light toward the first optical element. The first optical element defines first and second surfaces, a distance between the first and second surface varying as a function of distance along the first optical element, the first optical element thereby being configured to generate first and second reflected lines of light that reflect respectively from the first and second surfaces. A detector array receives the first and second lines of light, and generates an interferogram in response thereto. A computer processor determines a spectrum of the point of light, by analyzing the interferogram. Other applications are also described.

Abstract: Apparatus and methods are described for performing tear film structure measurement on a tear film of an eye of a subject. A broadband light source (100) is configured to generate broadband light. A spectrometer (250) is configured to measure a spectrum of light of the broadband light that is reflected from at least one spot on the tear film, the spot having a diameter of between 100 microns and 240 microns. A computer processor (28) is coupled to the spectrometer and configured to determine a characteristic of the tear film based upon the spectrum of light measured by the spectrometer. Other applications are also described.

Abstract: Apparatus and methods are described for determining tomographic and/or topographic data relating to an object. The object is illuminated with at least one wave packet from light generated by a multi-spectral light source. The wave packet is split into two split wave packets, and an optical path difference (OPD) is introduced between the two split wave packets, that is smaller than the coherence length of the wave packet. The two split wave packets are combined to generate a 2D image of the illuminated object, and the data relating to the object is determined by processing the 2D image using long coherence phase shift interferometry algorithms, by analyzing the 2D image as if the 2D image was generated using monochromatic light having a wavelength that is equal to a mean wavelength of the wave packet. Other applications are also described.

Abstract: Apparatus and methods are described for determining the tomography and/or topography of an object. A light source generates light, and an optical element generates a 2D pattern from the light and directs the 2D pattern toward the object. An objective lens focuses the 2D pattern at an image plane, and a 2D imager acquires at least one image of the 2D pattern. The image has variable image contrast that varies according to displacement of a surface of the object from the image plane, such that maximal image contrast of the 2D pattern is achieved when the surface of the object and the image plane are coincident. A processing unit, operatively coupled to the 2D imager, derives the object's tomography and/or topography at least partially responsively to the variable image contrast of the image. Other applications are also described.

Abstract: An apparatus and method for determining optical properties of an object includes a tunable monochromatic light source and an optical system for illuminating at least one point of the object with light from the light source, and collecting light reflected from the object. A biaxial birefringent crystal intercepts a beam of light reflected from the object and propagates the beam along an optical axis of the crystal and transforms the beam of reflected light to a ring of light having a periphery, each point of which has a different polarization plane. A detector array detects respective points along the periphery of the ring and a processing unit is coupled to the detector and is responsive to signals thereby for determining optical properties of the object.

Abstract: Apparatus and methods are described including a line spectrometer that receives a point of light. The line spectrometer includes a first optical element, and a second optical element configured to convert the point of light to a line of light and to direct the line of light toward the first optical element. The first optical element defines first and second surfaces, a distance between the first and second surface varying as a function of distance along the first optical element, the first optical element thereby being configured to generate first and second reflected lines of light that reflect respectively from the first and second surfaces. A detector array receives the first and second lines of light, and generates an interferogram in response thereto. A computer processor determines a spectrum of the point of light, by analyzing the interferogram. Other applications are also described.

Abstract: An apparatus and method for determining optical properties of an object includes a tunable monochromatic light source and an optical system for illuminating at least one point of the object with light from the light source, and collecting light reflected from the object. A biaxial birefringent crystal intercepts a beam of light reflected from the object and propagates the beam along an optical axis of the crystal and transforms the beam of reflected light to a ring of light having a periphery, each point of which has a different polarization plane. A detector array detects respective points along the periphery of the ring and a processing unit is coupled to the detector and is responsive to signals thereby for determining optical properties of the object.

Abstract: A method for high dynamic range and high accuracy interferometry measurements is described. The method uses a broadband light source for generating light, an interferometer, a phase shifting device, an imaging optical system and a detector array for collecting and measuring the reflected light from an object. The detected light is processed by a processor unit to obtain the object's surface.

Abstract: A system (10) for analyzing an object (11) includes a light source (12) producing multiple light components, each of different wavelength and a respective amplitude, phase and polarization. An optical element (13) directs the light components on to the object to create known 2D patterns at different image planes displaced from the optical element by distances that are known functions of the wavelength of the light component. A 2D imager (20) images the 2D patterns and produces a plurality of full view 2D wavelength dependent patterns each corresponding to a known distance from the optical element and each having variable image contrast dependent on displacement of a surface of the object from the image plane, maximal image contrast being achieved when the surface of the object and image plane are coincident. A processing unit (25) determines the object surface based on the variable image contrast of each image.

Abstract: An apparatus and method for determining optical properties of an object (50) includes a light source (10) and an optical system for illuminating at least one point of the object with light from the light source, and collecting light reflected from the object. A biaxial birefringent crystal (30) intercepts a beam of light reflected from the object and propagates the beam along an optical axis of the crystal and transforms the beam of reflected light to a ring of light having a periphery, each point of which has a different polarization plane. A detector array (40) detects respective points along the periphery of the ring and a processing unit (45) is coupled to the detector and is responsive to signals thereby for determining optical properties of the object.

Abstract: In a system for analyzing optical properties of an object (350) a point source of light (100) composed of multiple spectral bands each having a respective amplitude, phase and polarization is converted by first optics (120, 150) into a line light source to illuminate an object line on the object. A beam splitter (200) splits the light exiting the first optics and directs a first portion of light on to the object (350) as an illuminated line and a second portion of the light on to a reference mirror (450). Second optics (500) collects respective first and second lines of light reflected by the object and mirror of and collinearly images the reflected lines of light as an image line on to an imaging spectrometer (550) wherein mutual interference allows determination of the optical properties of the object at each point along the object line.

Abstract: Apparatus and methods are described, for detecting the surface topography of a portion of a curved surface of an object. A beam of light is directed toward the surface from a broad angle of incidence with respect to an optical axis of a camera. Light reflected from the surface is received by the camera, via a narrow-angle aperture. One or more darkened regions in the received light are detected, and the surface topography of portion of the surface is detected at least partially in response to the detected darkened regions. Other applications are also described.