In an ophthalmic imaging apparatus of some aspect examples, a data acquiring unit acquires data by applying an OCT scan to an eye. An image constructing unit constructs an image from the data acquired. A focal position changing unit is provided to the measurement arm. A scan controller controls the data acquiring unit according to a scan pattern including first and second partial patterns that are continuous patterns for central and peripheral regions of an OCT scan application area, respectively. A focus controller controls the focal position changing unit such that a first focal position is applied in parallel with an OCT scan of at least part of the first partial pattern and a second focal position is applied in parallel with an OCT scan to at least part of the second partial pattern.

Amplitude decorrelation measurement is sensitive to transverse flow and immune to phase noise in comparison to Doppler and other phase-based approaches. However, the high axial resolution of OCT makes it very sensitive to the pulsatile bulk motion noise in the axial direction, resulting in unacceptable signal to noise ratio (SNR). To overcome this limitation, a novel OCT angiography technique based on the decorrelation of OCT signal amplitude due to flow was created. The full OCT spectrum can be split into several narrower spectral bands, resulting in the OCT resolution cell in each band being isotropic and less susceptible to axial motion noise. Inter-B-scan decorrelation can be determined using the narrower spectral bands separately and then averaged. Recombining the decorrelation images from the spectral bands yields angiograms that use the full information in the entire OCT spectral range. Such images showed significant improvement of SNR for both flow detection and connectivity of microvascular networks when compared to other amplitude-decorrelation techniques. Further, creation of isotropic resolution cells can be useful for quantifying flow having equal sensitivity to axial and transverse flow. Such improved non-invasive imagery can be useful in the diagnosis and management of a variety of diseases.

The invention relates to an interferometric method, in which the light scattered by an object is imaged onto an electronic camera, wherein a sample light component is assigned to scattering sites on a sectional face in the interior of the object. This sample light component can he separated from the contributions of the other sample light components by processing of the camera image and leads to a sectional image. A particular advantage of the invention lies in the fact that multiple parallel sectional faces can be exposed sequentially at predetermined intervals from each other in the interior of the object. Such a sequence of sectional images can be used to calculate a solid model of the object.

The invention is applicable in particular to the live retina and allows a three-dimensional retina scan within a few seconds with a cost-effective and, if necessary, hand-held device.

Application options are in the fields of ophthalmology and in biometry.

System and method for geometric correction of OCT data representing a scan obtained by means of optical coherence tomography imaging of a sample. First scan morphological data relating to a morphology of the sample in the scan are obtained. Then reference morphological data relating to a reference morphology of the sample are obtained. For each of one or more scans of OCT data scan morphological data are compared with the reference morphological data to determine a relative geometric transformation of the morphology of the scan with respect to the reference morphology. Corrected scan is generated by performing on the OCT data representing the scan a transform that relates to the determined relative geometric transformation.

A sensor for a vibration imaging system is provided. The sensor includes a transmitter configured to project an array of laser beams onto a surface of an object such that neighboring beams in the array of laser beams are frequency shifted relative to each other, an interferometer configured to mix radiations reflected from neighboring points on the surface of the object such that the radiations from neighboring points interfere with one another, a photodetector array configured to produce output signals representative of the interfering beams, a demodulator configured to demodulate the output signals, and a computing device configured to calculate a deformation profile for the object based on the demodulated output signals.

A method performs phase shift interferometry to detect irregularities of a surface of a wafer after the wafer has been placed into an interferometer and while the wafer is vibrating. Additionally, a system and a non-transitory computer-readable storage medium have computer-executable instructions embodied thereon for performing phase shift interferometry to detect irregularities of a surface of a wafer after the wafer has been placed into an interferometer and while the wafer is vibrating.

Aspects concern an optical coherence tomography (OCT) system for imaging of a sample, comprising: a sample arm for directing light onto the sample, the sample arm comprises sample arm optics comprising a dispersive element to generate an extended source for illuminating the sample: a reference arm: a detector for detecting an interference signal from light that is reflected from the reference arm and light that is back-reflected or back-scattered from the sample; and a scanner for scanning the extended source across the sample along a fast axis and a slow axis such that a plurality of partial-spectrum frames is obtained at the detector: wherein the dispersive element is orientable such that the extended source is disposed at a non-zero angle to the fast axis.

Disclosed are several technical approaches of using low coherence interferometry techniques to create an autofocus apparatus for optical microscopy. These approaches allow automatic focusing on thin structures that are positioned closely to reflective surfaces and behind refractive material like a cover slip, and automated adjustment of focus position into the sample region without disturbance from reflection off adjacent surfaces. The measurement offset induced by refraction of material that covers the sample is compensated for. Proposed are techniques of an instrument that allows the automatic interchange of imaging objectives in a low coherence interferometry autofocus system, which is of major interest in combination with TDI (time delay integration) imaging, confocal and two-photon fluorescence microscopy.

The tomographic image capturing device of the present invention comprises a display means (18) configured to: split light from a light source (11) into measurement light and reference light and cause the measurement light and the reference light to be incident to an object (E) and a reference object (49), respectively; capture tomographic images of the object (E) on the basis of interference light generated by superposition of the measurement light reflected from the object (E) and the reference light reflected from the reference object (49); and display tomographic pictures of the object generated on the basis of the captured tomographic images. The tomographic image capturing device has a first image capturing mode and a second image capturing mode. The first image capturing mode is a mode in which the measurement light is two-dimensionally scanned by raster scan to be incident to the object (E) and the tomographic images of the object (E) are captured. The second image capturing mode is a mode in which the measurement light is two-dimensionally scanned by raster scan to be incident to the object (E) and the tomographic images of the object (E) are captured. The raster scan in the second image capturing mode is thinned from the raster scan in the first image capturing mode. The display means (18) is configured to be switchable between a first display mode and a second display mode. The first display mode is a mode in which a plurality of tomographic pictures including a region of interest of the object (E) is selected from among the tomographic pictures generated on the basis of the tomographic images captured in the second image capturing mode and only the selected plurality of tomographic pictures is displayed. The second display mode is a mode in which all of the tomographic pictures generated on the basis of the tomographic images captured in the second image capturing mode are in turn displayed. The capturing of the tomographic images in the first image capturing mode is performed after separately performing a first adjustment operation and a second adjustment operation for adjustment of an image capturing condition necessary for capturing the tomographic images in the first image capturing mode. The first adjustment operation is based on the tomographic pictures displayed in the first display mode. The second adjustment operation is based on the tomographic pictures displayed in the second display mode.

Described herein is an optical coherence tomograph (OCT) angiography technique based on the decorrelation of OCT signal amplitude to provide flow information. The full OCT spectrum can be split into several narrower spectral bands, resulting in the OCT resolution cell in each band being isotropic and less susceptible to axial motion nose. Inter-B-scan decorrelation can be determined using the individual spectral bands separately and then averaged. Recombining the decorrelation images from the spectral bands yields angiograms that use the full information in the entire OCT spectral range. Such images provide significant improvement of signal-to-noise ratio (SNR) for both flow detection and connectivity of microvascular networks compared to other techniques. Further, creation of isotropic resolution cells can be useful for quantifying flow having equal sensitivity to axial and transverse flow.