Disclosed is a stitching-measurement device adapted for performing stitching-measurement on a surface of a concave spherical lens, including: an interferometer, a reference lens, a first plane mirror, a second plane mirror, a first adjustment mechanism, a second adjustment mechanism, a concave spherical object to be measured, a motion table and a control mechanism, the first plane mirror being mounted on the first adjustment mechanism configured to change a position of the first plane mirror; the second plane mirror being mounted on the second adjustment mechanism configured to change a position of the second plane mirror; the concave spherical object to be measured being placed on the motion table configured to change a position of the concave spherical object to be measured; the control mechanism communicating with the interferometer, the first adjustment mechanism, the second adjustment mechanism, and the motion table for issuing control signals, wherein by the first adjustment mechanism and the second adjustment mechanism, an included angle between the first plane mirror and the second plane mirror is adjusted in such a way that light beam incident on the concave spherical object to be measured is inclined by a first angle relative to light beam emitted from the reference lens, thereby avoiding an operation of inclining the concave spherical object to be measured during the stitching-measurement.

A method and apparatus for characterizing the surface form of an optical element, in particular a mirror or a lens element of a microlithographic projection exposure apparatus, includes: carrying out a plurality of interferometric measurements, in each of which an interferogram is recorded between a test wave emanating from a portion of the optical element in each case and a reference wave, the position of the optical element relative to the test wave being altered between these measurements, and calculating the figure of the optical element on the basis of these measurements. This calculation is carried out iteratively such that, in a plurality of iteration steps, the figure of the optical element is ascertained in each case by carrying out a forward calculation, each of these iteration steps being based in each case on a reference wave that was adapted based on the preceding iteration step.

In some embodiments, systems, methods, and media for multiple reference arm spectral domain optical coherence tomography are provided which, in some embodiments, includes: a sample arm coupled to a light source; a first reference arm having a first path length; a second reference arm having a longer second path length; a first optical coupler that combines light from the sample arm and the first reference arm; a second coupler that combines light from the sample arm and the second reference arm; and an optical switch comprising: a first input port coupled to the first optical coupler; a second input coupled to the second coupler via an optical waveguide that induces a delay at least equal to an acquisition time of an image sensor; and an output coupled to the image sensor.

An exemplary system for generating an image(s) of a sample(s) can include, for example, an imaging arrangement that can include a superluminescent diode (SLD) configured to generate a radiation(s) to be provided to the sample(s), and a spectrometer configured to (i) sample an A-line sampling rate of at least about 200kHz, (ii) receive a resultant radiation from the sample(s) based on the sampling rate, and (iii) generate information based on the resultant radiation, and a computer hardware arrangement configured to generate the image(s) of the sample(s) based on the information received from the spectrometer. The imaging arrangement can be an interferometric imaging arrangement, which can be an optical coherence tomography imaging (OCT) arrangement. The computer hardware arrangement can be further configured to facilitate a plurality of b-scan acquisitions of the sample(s) and facilitate the b-scan acquisitions in order to generate the image(s).

In some embodiments, systems, methods, and media for multiple reference arm spectral domain optical coherence tomography are provided which, in some embodiments, includes: a sample arm coupled to a light source; a first reference arm having a first path length; a second reference arm having a longer second path length; a first optical coupler that combines light from the sample arm and the first reference arm; a second coupler that combines light from the sample arm and the second reference arm; and an optical switch comprising: a first input port coupled to the first optical coupler; a second input coupled to the second coupler via an optical waveguide that induces a delay at least equal to an acquisition time of an image sensor; and an output coupled to the image sensor.

A method, including: obtaining, by a processor, imaging data from a vessel; detecting, using the processor, an inner wall of the vessel based on the imaging data; identifying, using the processor, a plurality of visible edge portions of an outer wall of the vessel based on the imaging data; fitting, using the processor, a continuous surface model to the plurality of identified visible edge portions of the outer wall; and detecting, using the processor, the outer wall of the vessel based on fitting the continuous surface model to the plurality of identified visible edge portions of the outer wall such that the imaging data has defined therein a wall area between the inner wall and the outer wall of the vessel.

A low-coherence interferometer apparatus for determining information on interfaces of an object including: a polychromatic light source; an optical system generating a measurement optical beam and a reference optical beam; a delay line introducing a variable optical delay between the optical beams; detection optics combining the beams, and producing a spectral signal representative of an optical-power spectral density of the resulting interference signal; a control and processing module acquiring a plurality of spectral signals for a plurality of optical delays, determining, for each spectral signal, optical retardation information between interfering beams within a spectral measurement range, analyse the variation in the retardations, and assign the optical retardation determined on the basis of the different spectral signals to interface curves, corresponding to straight lines with positive, negative, zero or almost-zero gradient, depending on the respective optical delay of the acquisition of the spectral signals, and to deduce information of the object.

In some embodiments, systems, methods, and media for multiple reference arm spectral domain optical coherence tomography are provided which, in some embodiments, includes: a sample arm coupled to a light source; a first reference arm having a first path length; a second reference arm having a longer second path length; a first optical coupler that combines light from the sample arm and the first reference arm; a second coupler that combines light from the sample arm and the second reference arm; and an optical switch comprising: a first input port coupled to the first optical coupler; a second input coupled to the second coupler via an optical waveguide that induces a delay at least equal to an acquisition time of an image sensor; and an output coupled to the image sensor.

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.

System and method for profiling of a surface with lateral scanning interferometer the optical axis of which is perpendicular to the surface. In-plane scanning of the surface is carried out with increments that correspond to integer number of pixels of an employed optical detector. Determination of height profile of a region-of-interest that is incomparably larger than a FOV of the interferometer objective is performed in time reduced by at least an order of magnitude as compared to time required for the same determination by a vertical scanning interferometer.