Abstract: The invention relates to a system and to a corresponding method for optical coherence tomography having a light source (15) for producing light (14), a first interferometer (10), a second interferometer (20) and an optical fiber (17) by means of which light emitted by the first interferometer (10) is conveyed to the second interferometer (20). For simpler and more efficient injection of the light emitted by the first interferometer (10) into the optical fiber (17) provision is made such that light is injected into the first interferometer (10) which has a first number of transversal modes, and the optical fiber (17) has at least one multi-mode fiber into which the light passing out of the first interferometer (10) is injected such that in the optical fiber (17) a second number of transversal modes is stimulated which is conveyed to the second interferometer (20), the second number of transversal modes being substantially greater than the first number of transversal modes.

Abstract: The invention relates to a test device for testing a bonding layer between wafer-shaped samples and a test process for testing the bonding layer. The test device comprises a measuring head for an OCT process that is configured to direct an optical measuring beam at a composite comprising at least two wafer-shaped samples with a bonding layer positioned between them. An optical beam splitter is configured to divert an optical reference beam as a reference arm for distance measurements. An evaluation unit is configured to evaluate layer thickness measurements without a reference arm and distance measurements with a reference arm. An optical switch device is configured to connect and disconnect the reference arm.

Abstract: The invention relates to a system and to a corresponding method for optical coherence tomography having an interferometer (10) and a detector system (30, 31) which comprises a detector (30) for collecting the light reflected by a specimen (1) to be examined and has a sensitivity to the light reflected by the specimen (1). In order to reduce the times required for the most reliable possible recording of interference signals provision is made such that the sensitivity of the detector system (30, 31) to the light reflected by the specimen (1) and impinging on the detector (30) is modulated with a modulation frequency.

Abstract: The present invention provides a light source apparatus capable of producing stable oscillation and performing high-speed wavelength sweeping over a desired wavelength range. A swept light source apparatus in which oscillation wavelength is continuously changeable is provided. The apparatus includes, inside a resonator, an optical amplification medium that amplifies light, a first device configured to disperse light emitted from the optical amplification medium and thus produce beams having different wavelengths, a second device functioning as a non-focusing optical element and configured to collimate the beams having different wavelengths resulting from the dispersion by the first device, and a selecting device configured to select a beam having a specific wavelength from among the beams collimated by the second device. The beam having the specific wavelength selected by the selecting device is fed back to the optical amplification medium.

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: Provided is an optical tomographic imaging apparatus including: a unit for creating a measuring beam and a reference beam from beam of a light source, and generating interference light by combining a return beam resulting from the measuring beam and the reference beam; a unit for detecting the interference light to generate a detection signal; a unit for forming an image of the object based on the detection signal; a unit for designating a specific area in the image; a unit for setting a calculation index and a determination reference range used for determining image quality of the specific area; and a unit for applying calculation processing to a luminance value of the specific area based on the calculation index, determining whether a calculated value obtained as a result of the calculation processing is within the determination reference range, and outputting a detection result.

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: 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: A product critical temperature during freeze drying is determined. The product is imaged using optical coherence tomography (“OCT”). The product is freeze dried while the temperature of the product is measured. The product critical temperature is the temperature at which a product structure event occurs during freeze drying.

Abstract: Provided is an optical tomographic imaging apparatus that is capable of shortening a period of time of focusing at multiple focus positions when images split in a depth direction are obtained by zone focusing. The optical tomographic imaging apparatus includes: a focus position setting device for splitting a zone within a predetermined imaging depth range into multiple focus zones so as to set multiple focus positions; a reference position setting device for setting at least two reference positions in an imaging depth direction within the predetermined imaging depth range; and a focus controlling device for performing control so as to perform focusing at the multiple focus positions sequentially based on focus position information generated by the focus position setting device and a focus condition of in-focus at the at least two reference positions set in advance by the reference position setting device.

Abstract: Provided is a small, highly accurate Fourier spectrometer which enables highly accurate detection of an optical path difference in an interferometer. An element for changing to a narrow band is provided to return reflected light to a second light source (4), and the wavelength of light emitted by the second light source is locked, whereby the position of a movable mirror (8) is measured highly accurately and an optical path length (1) and an optical path length (2) match highly accurately.

Abstract: A photodetector of an OCT device is provided with: a silicon substrate comprised of a semiconductor of a first conductivity type, having a first principal surface and a second principal surface opposed to each other, and having a semiconductor region of a second conductivity type formed on the first principal surface side; and charge transfer electrodes provided on the first principal surface and transferring generated charges. In the silicon substrate, an accumulation layer of the first conductivity type having a higher impurity concentration than the silicon substrate is formed on the second principal surface side, and an irregular asperity is formed in a region opposed to at least the semiconductor region, in the second principal surface. The region in which the irregular asperity is formed on the second principal surface of the silicon substrate is optically exposed.

Abstract: Accordingly, exemplary embodiments of an apparatus probe catheter and method can be provided for irradiating a structure. In particular, an interferometer may forward forwarding an electromagnetic radiation. In addition, a sample arm may receive the electromagnetic radiation, and can include an arrangement which facilitates a production of at least two radiations from the electromagnetic radiation so as to irradiate the structure. Such exemplary arrangement can be configured to delay a first radiation of the at least two radiations with respect to a second radiation of the at least two radiations.

Abstract: An optical sensor, a method of configuring an optical sensor, and a method of using an optical sensor are provided. The optical sensor includes an optical waveguide having a length and a laser source optically coupled to the waveguide. The laser source has a coherence length. Light from the source is transmitted to the waveguide as a first signal propagating along the waveguide in a first direction and a second signal propagating along the waveguide in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the waveguide to generate a third signal. The coherence length is greater than 1 meter or is in a range between 200 microns and 10 centimeters.

Abstract: An optical tomographic image photographing apparatus includes: an OCT optical system for capturing tomographic images of an object to be examined, the OCT optical system including a light source, a splitter for splitting a light from the light source into a measurement optical path and a reference optical path, an optical scanner , and a detector for detecting a spectrum of light obtained by combining the light of the measurement optical path reflected from the object and the light from the reference optical path; a drive unit to move at least a part of optical components of the OCT optical system in an optical axial direction; a monitor to output at least the tomographic image; and a display controller for displaying the tomographic image and identifying information used to determine whether the tomographic image output to the monitor is a normal image or a reverse image.

Abstract: A four-dimensional optical coherence tomography imagining and guidance system includes an optical coherence tomography system, a data processing system adapted to communicate with the optical coherence tomography system, and a display system adapted to communicate with the data processing system. The optical coherence tomography system is configured to provide data corresponding to a plurality of volume frames per second. The data processing system is configured to receive and process the data and provide three-dimensional image data to the display system such that the display system displays a rendered real-time three-dimensional image.

Abstract: An improved interferometer measurement system is presented. In a preferred embodiment, a chirped fiber Bragg grating is used as a reference surface in a Fizeau interferometer arrangement for optical coherence tomography imaging of the eye. The grating creates a virtual reference surface near the sample and allows for a relatively short reference arm while maintaining close to zero delay interference conditions.

Abstract: An apparatus and method for optical coherence tomography are provided. The apparatus includes a light source configured to generate a plurality of beams, a light coupler configured to split the plurality of beams into measurement beams and reference beams, transmit the measurement beams to a target object via a probe, and receive response beams from the probe, a detector configured to detect interference signals based on interference between the response beams and the reference beams, and an image processor configured to generate a first image of the target object based on any one of the interference signals and generate a second image of the target object having image characteristics different from those of the first image based on an other one of the interference signals.

Abstract: Method and apparatus according to an exemplary embodiment of the present invention can be provided. For example, first data associated with a first signal received from at least one region of at least one sample can be provided based on a first modality, and second data associated with a second signal received from the at least one sample can be provided based on a second modality which is different from the first modality. Third data associated with a reference can be received. Further data can be generated based on the first, second and third data. In addition, third data associated with a second signal received from the at least one sample can be obtained. Each of the third data can be based on a further modality which is different from the first modality and the second modality, and the further data can be further determined based on the third data. Further, the first modality can be a spectral-encoded modality, and the second modality can be a non-spectral-encoding modality.

Abstract: A cam face 303a of a cam 303 has a shape depending on the distribution of the light amount in the cross-section of reference light LR. When the cam 303 is rotated by a stepping motor 302, an abutment 312 moves following the displacement of the cam face 302a with the rotation of the cam 303. A light-blocking link 310 rotates about the axis of rotation 311 with the movement of the abutment 312. A shield 313 moves in a first direction with the rotation of the light-blocking link 310 to change the shielding region of the reference light LR. A light-blocking plate 400 can shield the reference light LR from a second direction different from a shielding direction (first direction) by an attenuator 300. The light-blocking plate 400 is moved by a drive mechanism 410 and changes the shielding region.

Abstract: A main controller 211 controls a fiber-end drive mechanism 140 and an attenuator 121 with reference to the received-light amount of interference light LC to cause the following operations (1) and (2) to be executed alternately: (1) moving an emission end 116 to increase the received-light amount to at least an upper limit; and (2) changing the light amount of reference light LR to decrease the received-light amount to at least a lower limit. When the received-light amount specified by an received-light-amount specifying part 212 decreases in response to the movement of the emission end 116 in (1), the main controller 211 controls the fiber-end drive mechanism 140 to return the relative position to the immediately preceding status of this change. The main controller 211 leads the received-light amount of interference light LC by a CCD image sensor 120 to a target value by controlling the attenuator 121 to change the light amount of interference light LC.

Abstract: Dry oxygen, dry air, or other gases such as ozone are hermetically sealed within the package of the external cavity laser or ASE swept source to avoid packaging-induced failure or PIF. PIF due to hydrocarbon breakdown at optical interfaces with high power densities is believed to occur at the SLED and/or SOA facets as well as the tunable Fabry-Perot reflector/filter elements and/or output fiber. Because the laser is an external cavity tunable laser and the configuration of the ASE swept sources, the power output can be low while the internal power at surfaces can be high leading to PIF at output powers much lower than the 50 mW.

Abstract: An apparatus for measuring a layered object comprising a low coherence light source, a coherent light source, and an interferometer including a reference arm and a measurement arm. The reference arm is comprised of a first section of polarization maintaining optical fiber engaged with a first fiber stretcher. The measurement arm is comprised of a second section of polarization maintaining optical fiber engaged with a second fiber stretcher. The first and second fiber stretchers are driven so as to alternatingly vary the lengths of the first section of polarization maintaining optical fiber and the second section of polarization maintaining optical fiber, thereby causing interference signals with the low coherence light when the length of the reference arm is equal to the length of the measurement arm including the distance from the second section of polarization maintaining optical fiber to any of the surfaces of the layers of the object.

Abstract: Provided is an optical tomographic imaging apparatus that is capable of shortening a period of time of focusing at multiple focus positions when images split in a depth direction are obtained by zone focusing. The optical tomographic imaging apparatus includes: a focus position setting device for splitting a zone within a predetermined imaging depth range into multiple focus zones so as to set multiple focus positions; a reference position setting device for setting at least two reference positions in an imaging depth direction within the predetermined imaging depth range; and a focus controlling device for performing focusing at the multiple focus positions sequentially based on focus position information generated by the focus position setting device and a focus condition of an in-focus state for the at least two reference positions set in advance by the reference position setting device.

Abstract: Coherent and compact supercontinuum light sources for the mid IR spectral regime are disclosed and exemplary applications thereof. The supercontinuum generation is based on the use of highly nonlinear fibers or waveguides. In at least one embodiment the coherence of the supercontinuum sources is increased using low noise mode locked short pulse sources. Compact supercontinuum light sources can be constructed with the use of passively mode locked fiber or diode lasers. Wavelength tunable sources can be constructed using appropriate optical filters or frequency conversion sections. Highly coherent supercontinuum sources further facilitate coherent detection schemes and can improve the signal/noise ratio in lock in detection schemes.

Abstract: A new broadband source having a discrete set of spectral emission lines having high peak power in each line is provided by placing a gain medium in a reflective cavity comprising reflective front and back surfaces. A cavity feedback factor less than unity is achieved by providing reflectivity of one surface substantially lower than the reflectivity of the other surface such that spontaneous emission in the gain medium is linearly amplified just below the lasing threshold. In an alternative arrangement, a movable external back surface placed at a prescribed distance from the gain medium provides a means to achieve a free spectral range and finesse of the emission lines to match a pitch of a detector array in a SD-OCT system. By simultaneously providing high power to each detector element of the array, sensitivity and imaging speed of SD-OCT system are significantly improved.

Abstract: In a wavelength detector and an OCT including the same, the wavelength detector includes a wavelength filter by which at least one of the diffraction beams of a coherent input light is selected as a selection beam having a desired frequency by using a flat plate and at least a slit penetrating through the flat plate. The pixel having image data of an OCT image is mapped to the frequency of the selection beam by one to one, thereby improving uniformity of the resolution of the OCT image along a depth of the inspection object. The frequency of the selection beam is determined by an optical spectrum analyzer before initiating the OCT inspection to the object.

Abstract: A system for performing alignment of two wafers is disclosed. The system comprises an optical coherence tomography system and a wafer alignment system. The wafer alignment system is configured and disposed to control the relative position of a first wafer and a second wafer.

Abstract: A new broadband discrete spectrum light source comprising a gain medium placed in a feedback cavity is disclosed. A design for a feedback cavity including reflectors having raised-edge reflectivity is presented. Bandwidth enhancement is achieved by selectively enhancing the intensity of the discrete emission lines near the band edges of the gain medium spectrum. The bandwidth of a broadband discrete spectrum light source is further enhanced by digitally applying a spectral correction to each detected signal according to a predetermined correction profile. A combined effect of using a broadband discrete spectrum light source and applying spectral correction to the detected signal in an imaging system such as a Spectral Domain Optical Coherence Tomography (SD-OCT) imaging system, results in a desired spectral profile and a bandwidth necessary to achieve higher depth resolution for obtaining high quality diagnostic images.

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: The surface shape measuring system includes an illumination unit including a main light source, a focusing lens, and a projection lens; a beam splitter to split illumination light emitted respectively irradiated onto a reference surface and a measurement surface; a light detecting element to capture an interference pattern; and a control computer to obtain surface shape data through white-light interference pattern analysis from an image captured and detect whether or not the measurement surface is defective from the obtained data, wherein a subsidiary light source to provide falling illumination to the target object; and two-dimensional data and three-dimensional data regarding the surface shape of the target object are obtained by selectively intermitting the turning-on of the main light source and the subsidiary light source and the irradiation of the illumination light onto the reference surface.

Abstract: An optical imaging device which receives an optical collimated input beam, the device having a pair of axicon lenses through which a beam is directed to generate a collimated ring beam, wherein the ring beam is scattered from a substance to generate a return beam, and to bypass a reflector that redirects the return beam to prevent the return beam from interfering with the input beam; and a detector which detects an image projected by the return beam.

Abstract: An image forming method uses an optical coherence tomography as to an optical axis direction of plural pieces of image information of an object. First image information of an object is obtained at a first focus with respect to an optical axis direction to then object. A focusing position is changed by dynamic focusing from the first focus to a second focus along the optical axis. The second image information of the object is obtained at the second focus. A third image information, tomography image information of the object and including a tomography image of the first focus or the second focus, is obtained by Fourier domain optical coherence tomography. A tomography image or a three-dimensional image of the object is formed in positional relation, in the optical axis direction, between the first image information and the second image information using the third image information.

Abstract: In accordance with preferred embodiments of the present invention, a method for imaging tissue, for example, includes the steps of mounting the tissue on a computer controlled stage of a microscope, determining volumetric imaging parameters, directing at least two photons into a region of interest, scanning the region of interest across a portion of the tissue, imaging layers of the tissue, sectioning a portion of the tissue, capturing the sectioned tissue, and imaging additional layers of the tissue in a second volume of the tissue, and capturing each portion of sectioned tissue, and processing three-dimensional data that is collected to create a three-dimensional image of the region of interest. Further, captured tissue sections can be processed, re-imaged, and indexed to their original location in the three dimensional image.

Abstract: A device for establishing geometric values at least from a first region (MB1) and from a second region (MB3), distanced from the first region (MB1), of a transparent or diffusive object, comprises a coherence tomograph with an object arm, a reference arm, a detector arm, and a light source (ALQ) for emitting light. The device has a first path, formed by the object arm and/or the reference arm, having a first optical path length and a second path having a second optical path length, along which the light emitted by the light source (ALQ) can propagate.

Abstract: Interferometric path length measurements using frequency-domain interferometry form the basis of several measurement techniques, including optical frequency domain reflectometry (OFDR), optical coherence tomography (OCT), and frequency-modulated continuous wave (FMCW) radar and lidar. A phase-sensitive and self-referenced approach to frequency-domain interferometry yields absolute and relative path length measurements with axial precision orders of magnitude better than the transform-limited axial resolution of the system.

Abstract: Systems and methods are disclosed for optical coherence tomography (OCT). For example, imaging can use optical phase modulators based on optical delay lines that, in conjunction with a swept-source laser, can be used to achieve heterodyne swept source optical coherence tomography (SSOCT). These techniques resolve the complex conjugate ambiguity in SSOCT, thereby doubling the usable imaging range. This increased imaging range has numerous important clinical applications in ophthalmology, cardiology and radiology, as well as applications in small animal and non-biological imaging. These methods are superior to prior disclosed methods requiring acousto-optic or electro-optic modulators with respect to complexity, efficiency, imaging speed and image quality.

Abstract: In one aspect of the present invention, an apparatus includes a first light source for generating a broadband light, and a second light source for generating a monochromatic light, a beamsplitter optically coupled to the first light source for receiving the broadband light and splitting the received broadband light into a reference light and a sample light, a reference arm optically coupled to the beamsplitter for receiving the reference light and returning the received reference light into the beamsplitter, and a sample arm optically coupled to the beamsplitter and the second light source for combining the sample light and the monochromatic light, delivering the combined sample and monochromatic light to the target of interest, collecting a backscattering light and a Raman scattering light that are generated from interaction of the sample light and the monochromatic light with the target of interest, respectively, returning the backscattering light into the beamsplitter so as to generate an interference sign

Abstract: A light source device includes an optical resonator that includes an optical gain medium amplifying light and an optical waveguide having wavelength dispersion of a refractive index, and an optical modulator that modulates an intensity of the light in the optical resonator. An oscillation wavelength of an optical pulse is varied according to a modulation frequency of the optical modulator. The optical modulator can adjust transmittance of the light passing through the optical modulator, and a duty ratio of a transmission time of the light passing through the optical modulator is less than 50%.

Abstract: The invention provides a hybrid OCT scanning device which improves OCT scanning of targets, including adaption for a ophthalmic targets (i.e. cornea, retina and fovea areas). The invention provides a movable beam modifying element which is adapted to be interposed in the probe radiation directed to the target, and the interposition of the movable element is synchronous with the periodicity of the OCT scan beam. The beam modifying element may include any of angular deflection regions, optical delay regions, or combinations of deflection and delay regions. Such regions of deflection and/or delay translate into a governable scan range, both lateral and depth, of a target region.

Abstract: Imaging and visualization systems, instruments, and methods using optical coherence tomography (OCT) are disclosed. A method for OCT image capture includes determining a location of a feature of interest within an operative field. The method also includes determining a relative positioning between the feature of interest and an OCT scan location. Further, the method includes controlling capture of an OCT image at a set position relative to the feature of interest based on the relative positioning.

Abstract: A system and method for microscale measurement and imaging of the group refractive index of a sample. The method utilizes a broadband confocal high-numerical aperture microscope embedded into an interferometer and a spectrometric means, whereby spectral interferograms are analyzed to compute optical path delay of the beam traversing the sample as the sample is translated through the focus of an interrogating light beam. A determination of group refractive index may serve to disambiguate phase ambiguity in a measurement of refractive index at a specified wavelength. Spatial resolution of object characterization in three dimensions is achieved by imaging the object from multiple viewpoints.

Abstract: An optical detector system comprises a hermetic optoelectronic package, an optical bench installed within the optoelectronic package, a balanced detector system installed on the optical bench. The balanced detector system includes at least two optical detectors that receive interference signals. An electronic amplifier system installed within the optoelectronic package amplifies an output of at least two optical detectors. Also disclosed is an integrated optical coherence tomography system. Embodiments are provided in which the amplifiers, typically transimpedance amplifiers, are closely integrated with the optical detectors that detect the interference signals from the interferometer. Further embodiments are provided in which the interferometer but also preferably its detectors are integrated together on a common optical bench. Systems that have little or no optical fiber can thus be implemented.

Abstract: The disclosed automatic calibration systems and methods provide a repeatable way to detect internal catheter reflections and to shift the internal catheter reflections to calibrate an image.

Abstract: An optical coherence analysis system comprising: a first swept source that generates a first optical signal that is tuned over a first spectral scan band, a second swept source that generates a second optical signal that is tuned over a second spectral scan band, a combiner for combining the first optical signal and the second optical signal for form a combined optical signal, an interferometer for dividing the combined optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample, and a detector system for detecting an interference signal generated from the combined optical signal from the reference arm and from the sample arm. In embodiments, the swept sources are tunable lasers that have shared laser cavities.

Abstract: A system and method for artifact suppression in soft-field tomography are provided. One method includes obtaining an excitation pattern and applying the excitation pattern to an object, wherein the excitation pattern includes a plurality of frequency components. The method also includes measuring a response at one or more of a plurality of transducers coupled to the object and separating the responses among the plurality of frequency components to suppress one or more artifacts.

Abstract: An image forming method uses an optical coherence tomography as to an optical axis direction of plural pieces of image information of an object. First image information of an object is obtained at a first focus with respect to an optical axis direction to then object. A focusing position is changed by dynamic focusing from the first focus to a second focus along the optical axis. The second image information of the object is obtained at the second focus. A third image information, tomography image information of the object and including a tomography image of the first focus or the second focus, is obtained by Fourier domain optical coherence tomography. A tomography image or a three-dimensional image of the object is formed in positional relation, in the optical axis direction, between the first image information and the second image information using the third image information.

Abstract: The invention relates to a system for optical coherence tomography having an interferometer (20), a detector (30) with a first number of detector elements for collecting light, and an optical fiber (29) with a second number of individual fibers for transmitting light from the interferometer (20) to the detector (30). In order to increase the compactness of the system with at the same time high image quality provision is made such that the detector elements have a first center-center distance and the individual fibers have a second center-center distance, the first center-center distance between the detector elements being greater than the second center-center distance between the individual fibers.

Abstract: An image data set acquired by an optical coherence tomography (OCT) system is corrected for effects due to motion of the sample. A first set of A-scans is acquired within a time short enough to avoid any significant motion of the sample. A second more extensive set of A-scans is acquired over an overlapping region on the sample. A-scans from the first set are matched with A-scans from the second set. Comparison of the OCT scanner coordinates that produced each A-scan in a matching pair reveals the displacement of the sample between acquisition of the first and second A-scans in the pair. Estimates of the sample displacement are used to correct the transverse and longitudinal coordinates of the A-scans in the second set, to form a motion-corrected OCT data set.

Abstract: An optical coherence tomography device is disclosed for improved imaging. Reduced levels of speckle in the images generated by the device are obtained by forming a B-scan from a plurality of A-scans, wherein each resolution cell of the B-scan is generated through compounding of a subset of the A-scans and wherein at least some of the subset of A-scans are separated by at least half the diameter of a speckle cell both tangent to and orthogonal to the B-scan at that cell.