Systems and methods for improved interferometric imaging are presented. One embodiment is a partial field frequency-domain interferometric imaging system in which a light beam is scanned in two directions across a sample and the light scattered from the object is collected using a spatially resolved detector. The light beam could illuminate a spot, a line or a two-dimensional area on the sample. Additional embodiments with applicability to partial field as well as other types of interferometric systems are also presented.

A method for measuring a property of a test object with an interferometer includes: a) providing calibration information relating a focus setting for the interferometer to a position of the test object relative to a reference surface of the interferometer; b) determining the position of the test object relative to the reference surface; and c) using the interferometer to collect interferometric images of the test object for use in measuring the property of the test object.

An automatic calibration optical interferometer comprises: a light source; an optical interference assembly, which divides a low coherent light into a first and a second incident light; an optical sampling assembly, with a first end receiving the first incident light and a partially reflective window at the second end being configured to divide the first incident light into a first reflected light and a first penetrating light configured to be emitted to the test sample; an optical reference assembly, with a reference mirror and an actuator, wherein the optical sampling assembly emits the second incident light to the reference mirror to generate a second reflected light, and the actuator moves the reference mirror; a polychromator, which outputs a displacement signal according to an optical path difference variation between the first and second reflected lights; and a displacement controller, which controls the actuator according to the displacement signal.

An exemplary aspect is a method of processing data acquired by applying an optical coherence tomography (OCT) scan to a sample. The method includes preparing a three dimensional data set acquired from a sample, creating a two dimensional map based on representative intensity values of a plurality of pieces of A-scan data included in the three dimensional data set, placing the three dimensional data set based on the two dimensional map, and executing a process based on at least a partial data set of the three dimensional data set on which placement based on the two dimensional map has been performed.

An OCT imaging method of some exemplary aspects includes acquiring a first three dimensional data set by applying an OCT scan targeting a first three dimensional region of a sample, creating a first two dimensional map based on representative intensity values respectively of a plurality of pieces of A-scan data included in the first three dimensional data set, designating a second three dimensional region of the sample based on the first two dimensional map, acquiring a second three dimensional data set by applying an OCT scan targeting the second three dimensional region, and generating image data from at least part of the second three dimensional data set.

An OCT apparatus of an exemplary aspect includes an OCT scanner, image data generating unit, registration unit, and image data composing unit. The OCT scanner is configured to acquire three dimensional data sets by applying an OCT scan to mutually different three dimensional regions of a sample. The image data generating unit is configured to generate a plurality of pieces of image data from the three dimensional data sets. The registration unit is configured to perform a first registration between the plurality of pieces of image data by applying an image correlation calculation to each of overlap regions in the plurality of pieces of image data. The image data composing unit is configured to compose the plurality of pieces of image data based on a result of the first registration.

An artifact for determining resolution of imaging based on electromagnetic radiation, mechanical waves, or both is presented. The artifact includes a substrate and layers on top of the substrate. The layers include organic material and are stacked on each other in a partially overlapping way so that an edge of a first one of the layers is arranged to intersect with an edge of a second one of the layers. The layers constitute a three-dimensional surface topography where a groove defined by the edges of the first and second ones of the layers is tapering towards a point of intersection between the edges. The resolution is a minimum width of the tapering groove which is revealed by the imaging so that a pre-determined criterion is fulfilled.

Systems and methods for improved interferometric imaging are presented. One embodiment is a partial field frequency-domain interferometric imaging system in which a light beam is scanned in two directions across a sample and the light scattered from the object is collected using a spatially resolved detector. The light beam could illuminate a spot, a line or a two-dimensional area on the sample. Additional embodiments with applicability to partial field as well as other types of interferometric systems are also presented.

An artifact for determining resolution of imaging based on electromagnetic radiation, mechanical waves, or both is presented. The artifact includes a substrate and layers on top of the substrate. The layers include organic material and are stacked on each other in a partially overlapping way so that an edge of a first one of the layers is arranged to intersect with an edge of a second one of the layers. The layers constitute a three-dimensional surface topography where a groove defined by the edges of the first and second ones of the layers is tapering towards a point of intersection between the edges. The resolution is a minimum width of the tapering groove which is revealed by the imaging so that a pre-determined criterion is fulfilled.

The disclosure discloses a phase delay extraction and compensation method in a PGC phase demodulation technology. The sinusoidal phase modulation interference signal is converted into a digital interference signal by an analog-to-digital converter after amplification and filtering, and the digital interference signal is subjected to orthogonal downmixing of first-order, second-order, and fourth-order harmonics simultaneously to obtain three pairs of orthogonal harmonic amplitude signals. The three pairs of orthogonal harmonic amplitude signals are used to extract phase delay, and the result is used to calculate the corresponding phase delay correction coefficients, and the phase delay correction coefficient are multiplied by the corresponding absolute harmonic amplitude signal equal to the sum of the absolute value of the orthogonal harmonic amplitude signals to obtain a new harmonic amplitude signal that is not affected by the phase delay, then the phase to be measured is obtained through the arc tangent operation.