Abstract: A frequency swept laser source for TEFD-OCT imaging includes an integrated clock subsystem on the optical bench with the laser source. The clock subsystem generates frequency clock signals as the optical signal is tuned over the scan band. Preferably the laser source further includes a cavity extender in its optical cavity between a tunable filter and gain medium to increase an optical distance between the tunable filter and the gain medium in order to control the location of laser intensity pattern noise. The laser also include a fiber stub that allows for control over the cavity length while also controlling birefringence in the cavity.

Abstract: Optical coherence tomography (OCT) probe and system designs are disclosed that minimize the effects of mechanical movement and strain to the probe to the OCT analysis. It also concerns optical designs that are robust against noise from the OCT laser source. Also integrated OCT system-probes are included that yield compact and robust electro-opto-mechanical systems along with polarization sensitive OCT systems.

Abstract: Disclosed is a system including: (i) an interferometer configured to direct test electromagnetic radiation to a test surface and reference electromagnetic radiation to a reference surface and subsequently combine the electromagnetic radiation to form an interference pattern, the electromagnetic radiation being derived from a common source; (ii) a multi-element detector; and (iii) one or more optics configured to image the interference pattern onto the detector so that different elements of the detector correspond to different illumination angles of the test surface by the test electromagnetic radiation.

Abstract: An optical coupler for coupling to a rotating catheter has a housing with a rotatable distal face and a stationary proximal face. The distal face has an eccentric port and a central port. A lens is disposed inside the housing to intercept a rotating collection beam emerging from the eccentric port and to re-direct the collection beam to a focus proximal to the lens as the collection beam rotates. A beam re-director disposed between the lens and the distal face is oriented to direct a delivery beam toward the central port.

Abstract: A broadband interferometric vertical scan of a sample surface is performed to produce interference data in conventional manner. A coarse surface profile of the surface is obtained in real time using a conventional technique, such as a center-of-mass calculation. A fine surface map is obtained concurrently using a quadrature-demodulation algorithm applied in real time to the same interference data used for the coarse surface calculation. The fine surface map is then combined with the coarse surface profile using an unwrapping technique that produces a final surface map with sub-nanometer resolution within a large height range.

Abstract: Frequency domain optical coherence imaging systems have an optical source, an optical detector and an optical transmission path between the optical source and the optical detector. The optical transmission path between the optical source and the optical detector reduces an effective linewidth of the imaging system. The optical source may be a broadband source and the optical transmission path may include a periodic optical filter.

Abstract: Methods and apparatus for three-dimensional imaging of a sample. A source is provided of a beam of substantially collimated light characterized by a temporally dependent spectrum. The beam is focused in a plane characterized by a fixed displacement along the propagation axis of the beam, and scattered light from the sample is superposed with a reference beam derived from the substantially collimated source onto a focal plane detector array to provide an interference signal. A forward scattering model is derived relating measured data to structure of an object to allow solution of an inverse scattering problem based upon the interference signal so that a three-dimensional structure of the sample may be inferred in near real time.

Abstract: A compensation table for compensating interference signal obtained by OCT measurement is generated easily. When a reflection body interference signal is obtained by OCT measurement, the reflection body interference signal is compensated by a compensation table (Formula (1)) to obtain an evaluation output signal. Then, a spectrum of the evaluation output signal is calculated to obtain an evaluation value of the spectrum. Thereafter, a model coefficient is updated such that the evaluation value becomes small.

Abstract: Fourier domain a/LCI (faLCI) system and method which enables in vivo data acquisition at rapid rates using a single scan. Angle-resolved and depth-resolved spectra information is obtained with one scan. The reference arm can remain fixed with respect to the sample due to only one scan required. A reference signal and a reflected sample signal are cross-correlated and dispersed at a multitude of reflected angles off of the sample, thereby representing reflections from a multitude of points on the sample at the same time in parallel. Information about all depths of the sample at each of the multitude of different points on the sample can be obtained with one scan on the order of approximately 40 milliseconds. From the spatial, cross-correlated reference signal, structural (size) information can also be obtained using techniques that allow size information of scatterers to be obtained from angle-resolved data.

Abstract: Some embodiments of the present invention provide optical coherence tomography systems including an OCT engine and a processor. The OCT engine is configured to provide both standard OCT imaging and spectral domain phase microscopy (SDPM) imaging. The processor is coupled to the OCT engine and is configured to use a first signal processing method when the OCT engine is configured to provide standard OCT imaging and a second signal processing method when the OCT engine is configured to provide SDPM imaging. Related methods and computer program products are also provided.

Abstract: An optical tomograph obtains tomographic images by administering frequency analysis on an interference light beam formed by interference between a reflected light beam, which is a measuring light beam reflected by a measurement target, and a reference light beam. A tomographic data obtaining section obtains tomographic data to be used for optical path length adjustment each time that the position, onto which the measuring light beam is irradiated, is changed. An optical path length adjusting section adjusts the optical path length of one of the measuring light beam, the reflected light beam, and the reference light beam, based on the obtained tomographic data.

Abstract: A method for determining a spatial property of an object includes obtaining a scanning low coherence interference signal from a measurement object that includes two or more interfaces. The scanning low coherence interference signal includes two or more overlapping low coherence interference signals, each of which results from a respective interface. Based on the low coherence interference signal, a spatial property of at least one of the interfaces is determined. In some cases, the determination is based on a subset of the low coherence interference signal rather than on the entirety of the signal. Alternatively, or in addition, the determination can be based on a template, which may be indicative of an instrument response of the interferometer used to obtain the low coherence interference signal.

Abstract: A geometric measurement system is adapted to precisely measure one or more surfaces of objects such as corneas, molds, contact lenses in molds, contact lenses, or other objects in a fixture. The geometric measurement system can employ one or more of three possible methods of measurement: Shack-Hartmann wavefront sensing with wavefront stitching; phase diversity sensing; and white light interferometry.

Abstract: In one embodiment, a system to measure defects on a surface of a wafer and an edge of the wafer using a single tool comprises a radial motor to move an optical head in a radial direction to detect defects at locations displaced from the edge of the wafer, and a rotational motor to rotate the optical head around the edge of the wafer to detect defects on the edge of the wafer.

Abstract: An apparatus is provided for measuring a frequency-domain optical coherence tomography power spectrum from a sample. The apparatus includes a broadband light source, an optical spectrum analyzer, and a partially reflective element optically coupled to the light source, to the optical spectrum analyzer, and to the sample. A first portion of light from the light source is reflected by the partially reflective element and propagates to the optical spectrum analyzer. A second portion of light from the light source propagating through the partially reflective element, impinging the sample, reflecting from the sample, and propagating to the optical spectrum analyzer.

Abstract: The present invention provides a three-dimensional shape measurement method and a three-dimensional shape measurement apparatus. Color luminance data I (x, y) is separated by an arithmetic processing unit into R, G and B which are color components of a color image. Then, maximum amplitude values are calculated, and the maximum values are composed to obtain an in-focus color omnifocal image. Further, a Z-position corresponding to the maximum amplitude value in an interferogram is calculated in at least one color component, and this processing is performed for all pixels (x, y) to calculate height information for a sample. The height information is provided to the color omnifocal image, such that the three-dimensional shape of the sample can be measured.

Abstract: Light beams swept in wavelength repeatedly within first and second wavelength ranges respectively are outputted from a light source unit at the same time. Each light beam is split into measuring and reference beams. Reflected beams from a measuring object when the measuring beams are irradiated on the measuring object are combined with the reference beams. The wavelengths of the interference beams produced thereby are divided into three wavelength ranges, for example, a range not greater than 0.9 ?m, a range from 0.9 to 1.2 ?m, and a range longer than 1.2 ?m by a wavelength dividing means to obtain interference signals. In the wavelength range from 0.9 to 1.2 ?m which includes an overlapping wavelength range where the wavelength ranges of the light beams overlap with each other, either one of the light beams is outputted from the light source unit.

Abstract: A method of measuring the topography of a large, thin, non-flat specular substrate in a production environment with minimal movement of a majority of the measurement apparatus. A gimbal-mounted reflecting element is used to steer a short coherence length probe beam such that the probe beam is substantially perpendicular to a local surface of the substrate. The probe beam and the reference beam are combined and the resulting interference pattern used to characterize defects on the local surface.

Abstract: Speckle, a factor reducing image quality in optical coherence tomography (“OCT”), can limit the ability to identify cellular structures that are important for the diagnosis of a variety of diseases. Exemplary embodiments of the present invention can facilitate an implementation of an angular compounding, angular compounding by path length encoding (“ACPE”) for reducing speckle in OCT images. By averaging images obtained at different incident angles, with each image encoded by path length, ACPE maintains high-speed image acquisition and implements minimal modifications to OCT probe optics. ACPE images obtained from tissue phantoms and human skin in vivo demonstrate a qualitative improvement over traditional OCT and an increased signal-to-noise ratio (“SNR”). Accordingly, exemplary embodiments of an apparatus probe catheter and method can be provided for irradiating a sample. In particular, an interferometer may forward forwarding an electromagnetic radiation.

Abstract: The present invention provides an OCT technique that permits tomographic observation of a biological body parts that is difficult to restrain and also provides a tomographic observation technique for the observation of a constrainable part that does not require constraint and remove the burden from biological body. A wavelength-tunable light generator (wavelength-tunable light source) is employed as the light source of the optical coherence tomography device. The wavelength-tunable light generator has a wave number tunable range width of at least 4.7×10?2 ?m?1 and an emitted-light frequency width of no more than 13 GHz, for example, and includes means capable of changing the wave number stepwise at wave number intervals of no more than 3.1×10?4 ?m?1 and time intervals of no more than 530 ?s.

Abstract: Methods and systems are disclosed for analyzing a scanning interferometry signal. Steps include: providing a scanning interferometry signal produced by a scanning interferometer for a first location of a test object (e.g., a sample having a thin film); providing a model function of the scanning interferometry signal produced by the scanning interferometer, wherein the model function is parameterized by one or more parameter values; fitting the model function to the scanning interferometry signal for each of a series of shifts in scan position between the model function and the scanning interferometry signal by varying the parameter values; and determining information about the test object (e.g., a surface height or height profile, and/or a thickness or thickness profile for a thin film in the test object) at the first location based on the fitting.

Abstract: A system, method and apparatus for anatomical mapping utilizing optical coherence tomography. In the present invention, 3-dimensional fundus intensity imagery can be acquired from a scanning of light back-reflected from an eye. The scanning can include spectral domain scanning, as an example. A fundus intensity image can be acquired in real-time. The 3-dimensional data set can be reduced to generate an anatomical mapping, such as an edema mapping and a thickness mapping. Optionally, a partial fundus intensity image can be produced from the scanning of the eye to generate an en face view of the retinal structure of the eye without first requiring a full segmentation of the 3-D data set. Advantageously, the system, method and apparatus of the present invention can provide quantitative three-dimensional information about the spatial location and extent of macular edema and other pathologies.

Abstract: Low coherence light is divided into measuring light and reference light. The measuring light is collected to be projected onto an object of measurement. Intensities of the reflected light in a plurality of positions in the direction of depth are detected by carrying out a Fourier analysis on each channeled spectrum obtained by decomposing the detected interference light into frequency components. The optical path length of the reference light is stepwise changed to adjust the optical path length within the focusing range of the measuring light. A plurality of pieces of data representing the intensity of the reflected light are obtained in a plurality of positions in the direction of depth each time the position of the focusing range changes, and data on the position in the direction of depth where the measuring light is in the focusing range is extracted out of the pieces of data.

Abstract: An apparatus using optical coherence tomography based on spectral interference and an ophthalmic apparatus, which can accurately obtain information on an object in a depth direction by correcting misalignment between an optical member of a spectral optical system and a photodetector, includes an interference optical system for irradiating measurement light being low coherent light onto the object and synthesizing the measurement light reflected from the object and reference light being low coherent light to interfere, a spectral optical system which disperses interference light for every frequency, a photodetector photo-receiving the dispersed interference light, means guiding calibration light for adjusting alignment between the spectral optical system and the photodetector to the spectral optical system, means storing reference spectral information, and means adjusting the alignment based on a comparison between spectral information on the calibration light guided to the spectral optical system and photo-re

Abstract: Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code.

Abstract: A coherence remover includes a first partially reflective surface and a second partially reflective surface. The coherence remover is configured to receive an input beam. Each of the first and second reflective surfaces is configured to reflect a respective portion of the input beam to produce respective one or more intermediate beams. The intermediate beams collectively form an output beam that has a reduced coherence compared to the input beam.

Abstract: A first beam having high coherence and a second beam having low coherence and having a central wavelength difference from that of the first beam are multiplexed onto the same optical axis. First and second multiplexed beams obtained by beam splitting are emitted at a measurement reflection plane and a reference plane, respectively. The reflected first and second multiplexed beams are multiplexed and interfere with each other. The interference generates a first interference signal that is obtained from the first beams at the interference unit and that relates to information on the distance to the measurement reflection plane and a second interference signal that is obtained from the second beams. The first and second interference signals are used to carry out calculations for determining the position of a measurement origin for the measurement reflection plane.

Abstract: The present invention is a tunable semiconductor laser for swept source optical coherence tomography, comprising a semiconductor substrate; a waveguide on top of said substrate with multiple sections of different band gap engineered multiple quantum wells (MQWs); a multiple of distributed feedback (DFB) gratings corresponding to each said band gap engineered MWQs, each DFB having a different Bragg grating period; and anti-reflection (AR) coating deposited on at least the laser emission facet of the laser to suppress the resonance of Fabry-Perot cavity modes. Each DFB MQWs section can be activated and tuned to lase across a fraction of the overall bandwidth as is achievable for a single DFB laser and all sections can be sequentially activated and tuned so as to collectively cover a broad bandwidth, or simultaneously activated and tuned to enable a tunable multi-wavelength laser.

Abstract: Some embodiments of the present invention provide optical coherence tomography systems including an OCT engine and a processor. The OCT engine is configured to provide both standard OCT imaging and spectral domain phase microscopy (SDPM) imaging. The processor is coupled to the OCT engine and is configured to use a first signal processing method when the OCT engine is configured to provide standard OCT imaging and a second signal processing method when the OCT engine is configured to provide SDPM imaging. Related methods and computer program products are also provided.

Abstract: A method and apparatus for providing information associated with at least one portion of a sample can be provided. For example, at least one wavelength of electro-magnetic radiation provided on a sample can be encoded to determine at least one transverse location of the portion. A relative phase between at least one first electro-magnetic radiation electro-magnetic radiation being returned from a sample and at least one second electro-magnetic radiation returned from a reference can be obtained to determine at least one relative depth location of the portion. Further, the information of the portion can be provided based on the transverse location and the relative depth location. For example, the information can be depth information and/or three-dimensional information associated with the portion of the sample.

Abstract: In an OCT apparatus, an object light beam is returned from a target and interferes with a reference light beam. Image information is obtained from a depth Z in the target that depends on the optical path difference between the object and reference beams with a resolution that depends on the coherence length of the light. A scanner transversely scans the target with the object beam over a plurality of image points defined by the resolution of the apparatus. Interface optics directs the reference and object beams onto an array of detector elements such that the optical path difference between the reference beam and the object beam varies across the array. The reference beam and the object beam interfere with each other over the array of detector elements for individual image points on the target during each transverse scan. A memory stores a subset of data points corresponding to each individual image point obtained from each detector elements of the array.

Abstract: An optical image measuring apparatus including: a beam splitter (4) for dividing a light beam into signal light (S) and reference light (R); beam splitters for dividing the reference light (R) into plural reference light beams frequency shifters for shifting frequencies of the reference light beams by different amounts; and reflector plates arranged at different distances from an object to be measured (O). The reference light beams and the signal light (S) reflected by the object to be measured in depth regions are superimposed on each other to thereby produce interference light. CCD cameras receive the interference light component and convert the interference light component into electrical signals to output the signals. A computer forms images in depth regions corresponding to the interference light components based on the electrical signals.

Abstract: An interferometric axial eye length measurement apparatus having a light source adapted to produce a beam of partially coherent light, a first mirror and a second mirror disposed in the reference arm, and a processor adapted to control at least the second mirror such that a corneal interference peak and a second interference peak have a non-zero separation. There is at least one variable delay optical element having a delay signal, wherein the delay signal corresponding to a region between the corneal interference peak and second interference peak is substantially linear.

Abstract: The apparatus according to the invention comprises an object lens which can operate in at least two different measuring modes. In a first, interference mode a workpiece is measured by means of interference optometry. In a second, imaging measuring mode an optical image is produced, for example, on a camera-like detector array and may be applied to an image processing routine. Switching between the two measuring modes is performed by the type of illumination of the object lens and an element which is disposed preferably in the reference beam path of an interferometer and which activates or deactivates the reference beam path dependent on the spectral composition of the utilized light. In this manner a simple and rapid changeover between the two measuring modes is provided, without the need for replacing or even for moving the object lens.

Abstract: The present invention relates to an interferometric measuring device having a short-coherent radiation source, a modulation interferometer and a downstream reference interferometer connected thereto. The mechanical coupling between the reference interferometer and the modulation interferometer is provided with a backlash. For equalizing an optical path difference in the interferometric measuring device, an optical path difference established in the modulation interferometer is reset in the reference interferometer. The optical path differences between the partial beams in the modulation interferometer and between the partial beams in the reference interferometer may be changed via optical components mechanically coupled with the aid of a backlash, the movable optical component of the reference interferometer following a movement of the movable optical component of the modulation interferometer after passing a backlash distance in the backlash.

Abstract: A system for imaging a sample is provided that includes an optical coherence tomography (OCT) portion having an associated OCT path. A second imaging portion is provided having an associated second image path, different from the OCT path. A fixation target having an associated fixation path, different from the second image path and the OCT path is also provided. The OCT path, the second image path and the fixation path are confocal at a common image plane. Related handheld systems are also provided.

Abstract: A method capable of accurately measuring a physical quantity of a measurement object in a substrate processing apparatus. In a temperature measurement apparatus for implementing the method, two interference positions are measured at different timings when a reference mirror is caused to move in the direction away from a collimator fiber, and a difference between the two interference positions is calculated. When the reference mirror remote from the collimator fiber is caused to move toward the collimator fiber, two interference positions are measured at different timings, and a difference between the two interference positions is calculated. An average value of the interference position differences is calculated, an optical path length difference is determined from the average value, and a wafer temperature is calculated from the optical path length difference.

Abstract: In common path time domain OCT/OCR devices optical radiation from a source is first split into two replicas, which are then delivered to an associated sample by an optical fiber probe. The tip of the optical fiber probe serves as a reference reflector and also serves as a combining element that produces a combination optical radiation by combining an optical radiation returning from the associated sample with a reference optical radiation reflected from the reference reflector. The topology of the devices eliminates the necessity of using Faraday mirrors, and also allows for registering a cross-polarized component of the optical radiation reflected or backscattered from the associated sample, as well as a parallel-polarized component.

Abstract: A method for determining the surface topography of an object with various surface properties in white light interferometry first generates a set of interferograms, produced by a phase shift driving mechanism supplied with known inputs, obtained from a single reflective surface at the location of the test piece. The sequence of interferograms from the test piece then is used to calibrate a sequence of inputs to the phase shift driving mechanism to compensate for non-linear characteristics of the phase shifting mechanism. The temporal interferometric signal or its transform at each pixel of a set of subsequently acquired interferograms from a test piece then is compared with signals or their transforms modeled with different properties of the measuring surface. The measured surface properties which generate a best match to the modeling surface properties are selected as the desired signal.

Abstract: An apparatus and a method for detecting surface motion of an object subject to ultrasound are disclosed. The method comprises generating a laser beam, dividing the laser beam into a reference beam and an object beam to be directed onto the surface, thereby producing a scattered object beam, introducing a frequency shift between the reference beam and the scattered object beam, wherein the frequency shift is smaller than the ultrasonic frequency, detecting the interference between the scattered object beam and the frequency shifted reference beam using a plurality of detecting elements to generate a plurality of electrical interference signals, wherein the electrical interference signals each comprise a wanted signal component indicative of the surface motion and a noise signal component, and processing the electrical interference signals to determine the surface motion of the object.

Abstract: An interferometric measuring device, especially for measuring the shape of a surface of an object, includes a radiation source emits a short coherent electromagnetic radiation, a component, in particular a beam splitter, to form an object beam that is guided to the object via an object light path, and a reference beam guided to a reference plane via a reference light path, and a pickup element, by the use of which an electromagnetic radiation, that is reflected by the object and the reference plane and brought to interference, is able to be picked up. In this context, an adaptive optical element is provided, with the aid of which the imaging of the object on the pickup element and/or the wave front of the reference beam and/or the optical path length in the reference light path and/or in the object light path may be influenced.

Abstract: A device for tomographic scanning objects comprises a source of light for irradiating the object; a first grid arranged in the optical axis of the light beam so that a pattern of the first grid is projected on the object; an optical imaging assembly for imaging the object on a sensor; and a second grid provided in the optical axis of the reflected light beam having a pattern matching the first grid, through said second grid the reflected light beam having the pattern of the first grid being guided so that the sensor senses the light beam reflected by the object with a Moiré pattern resulting from overlying the pattern of the first grid and the pattern of the second grid. The device further comprises a means for moving the first grid and/or the second grid at a frequency causing fluctuations in the intensity of the resulting Moiré pattern.

Abstract: Systems and methods for digital detection of an analog tomographic signal are described. The methods include receiving an amplitude-modulated analog signal containing tomographic information, the analog signal having a modulation frequency, f?i; and converting the analog signal into a digital signal at a sampling frequency, fs, to produce a number of samples, K. The digital signal is multiplied by an in-phase reference signal to obtain an in-phase signal component, the in-phase reference signal having the frequency, f?i; and the digital signal is multiplied by a quadrature reference signal to obtain a quadrature signal component, the quadrature reference signal having the frequency, f?i. The in-phase signal component and the quadrature signal component are passed through the K-point averaging filter. A signal amplitude is computed based on the filtered in-phase signal component and the filtered quadrature signal component, the signal amplitude being representative of the tomographic information.

Abstract: In general, in one aspect, the invention features a method that includes transforming interferometry data acquired for a test sample using a low coherence imaging interferometry system to a frequency domain and, at a plurality of frequencies in the frequency domain, reducing contributions to the transformed interferometry data due to imperfections in the imaging interferometry system thereby producing compensated interferometry data. The errors are reduced based on variations between interferometry data acquired using the low coherence imaging interferometry system for a calibration sample and model interferometry data corresponding to data acquired for the calibration sample using a model interferometry system.

Abstract: A method for determining a spatial property of an object includes obtaining a scanning low coherence interference signal from a measurement object that includes two or more interfaces. The scanning low coherence interference signal includes two or more overlapping low coherence interference signals, each of which results from a respective interface. Based on the low coherence interference signal, a spatial property of at least one of the interfaces is determined. In some cases, the determination is based on a subset of the low coherence interference signal rather than on the entirety of the signal. Alternatively, or in addition, the determination can be based on a template, which may be indicative of an instrument response of the interferometer used to obtain the low coherence interference signal.

Abstract: A method of acquiring a vertical section image of lingual fur, and an apparatus to perform the method, the method including generating interfering light from irradiated light and light reflected from a tongue tissue, and generating a partial image corresponding to a relative intensity of the generated interfering light.

Abstract: An in-vivo high resolution lateral and axial tomography system of the retina, is provided, including a Michelson interferometer, generating a tomographical image by full field OCT interference with Z sweeping, adaptive optical correction apparatus, correcting the wave fronts coming from and going to the eye, including a reference source, a deformable mirror and wave surface analysis apparatus, detection apparatus producing an image from an interferometric measurement using the OCT principle and apparatus for focussing the wave surface analyser. The apparatus for focussing are embodied and controlled, synchronously with the Z sweeping to force the deformable mirror to adopt an additional curvature, such as to combine the input light source and detection apparatus at a given depth in the retina.

Abstract: The technology described here enables the use of an inexpensive laser to measure an interferometric response of an optical device under test (DUT) at reflection lengths significantly greater than the coherence length of the laser. This is particularly beneficial in practical interferometric applications where cost is a concern. In other words, inexpensive lasers having shorter coherence lengths may be used to achieve very high interferometric measurements at longer DUT reflection lengths. The technology also enables the use of such inexpensive lasers to measure Rayleigh scatter in commercial-grade, single-mode optical fiber.

Abstract: The invention relates to studies of internal structures of objects with the aid of optical means. According to the invention an optical system (15) of the delivering device for low coherence optical radiation, in a particular embodiment, an optical fiber probe (8), includes at least two lens components (19), (20), which have a positive focal power and are positioned substantionally confocally. This ensures a constant propagation time for the low coherence optical radiation propagating from a given point of the transverse scanning surface (28) or (39) to a corresponding conjugate point of the image plane (22). That provides elimination of the transverse scanning related aberration of the optical path length for low coherence optical radiation directed towards the object (11) both for a flat transverse scanning surface (28) and for a transverse scanning surface (39) having a curvature.

Abstract: A method of building up a three dimensional OCT image of an object having a limited region sensitive to movement of a scanning beam performs an OCT scan in a scanning pattern that results in said limited region, typically the fovea of the eye, being scanned last.