Examples of the disclosure relate to an apparatus (101), a wearable electronic device and an optical arrangement for optical coherence tomography. The apparatus comprises an optical coherence tomography system (103) and an optical arrangement (105). The optical arrangement comprises at least one means for beam shaping (109) configured to shape a beam of light from the optical coherence tomography system. The optical arrangement also comprises at least one minor (111) positioned so that light from the means for beam shaping is incident on the at least one minor. The at least one mirror is configured to move in at least one direction relative to the optical coherence tomography system.

A method for wavefront measurement of optical imaging system based on grating shearing interferometry, the grating shearing interferometer comprising: a light source and illumination system, an optical imaging system to be tested, a one-dimensional diffraction grating plate, a two-dimensional diffraction grating plate, a two-dimensional photoelectric sensor and a computing unit. The one-dimensional diffraction grating plate and the two-dimensional diffraction grating plate are respectively placed on the object side and the image side of the optical imaging system to be tested. By collecting N sets of interferograms with a

[00001]$\frac{2.Math.}{N}$

phase-shifting interval (where,

[00002]$N=2.Math.\left(\mathrm{fix}\left(\frac{\mathrm{ceil}\left(1/s\right)}{2}\right)+1\right),$

s is the shear ratio of the grating shearing interferometer), combined with a certain phase retrieval algorithm, the influence of all high-order diffraction beams on the phase retrieval accuracy is eliminated, and finally the wavefront measurement accuracy for the optical imaging system is improved.

Provided is a fast parallel optical coherence tomographic image generating method including dispersing light into N spectral regions .sub.1 through .sub.N sequentially from a low frequency wavelength to a high frequency wavelength, the light being emitted from a broadband light source of a fast parallel optical coherence tomographic image generating apparatus, N being an integer greater than or equal to 2, splitting the light emitted from the broadband light source to be incident on a sample and a reference mirror, partitioning the sample into N image regions P.sub.1 through P.sub.N, discretely controlling a beam scanner such that the light emitted from the broadband light source is incident on the sample at a position changed by a preset distance, acquiring an interference spectral image through interference light formed in response to interference of measurement light and reference light, and generating a tomographic image of the sample using the interference spectral image.

A method is provided for observing structure and function of individual cells in a living human eye, comprising: using an adaptive optics optical coherence tomography (AO-OCT) system to image a volume of a retinal patch including numerous cells of different types, as for example, ganglion cells; using 3D subcellular image registration to correct for eye motion, including digitally dissecting the imaged volume; and using organelle motility inside the cell to increase cell contrast and to measure cell temporal dynamics.

Disclosed are devices and techniques based on optical coherence tomography (OCT) technology in combination with optical actuation. A system for providing optical actuation and optical sensing can include an optical coherence tomography (OCT) device that performs optical imaging of a sample based on optical interferometry from an optical sampling beam interacting with an optical sample and an optical reference beam; an OCT light source to provide an OCT imaging beam into the OCT device which splits the OCT imaging beam into the optical sampling beam and the optical reference beam; and a light source that produces an optical actuation beam that is coupled along with the optical sampling beam to be directed to the sample to actuate particles or structures in the sample so that the optical imaging captures information of the sample under the optical actuation.

A method of forming a Chemically Vapour Deposited polymeric conformal coating on a surface of a part (23). The method comprises placing the part (23) and a deposition regulator (28) in a deposition chamber (22); dispersing a gas into the chamber (22) from which the polymeric coating is deposited on the surface. The deposition regulator (28) is configured to control a localised flow of the gas in the deposition chamber (22) to promote a more uniform layer thickness of the polymeric coating on the surface.

A measurement arrangement and a method for measuring a wavefront aberration of an imaging optical system (10) of a microlithographic projection exposure apparatus. The method includes separate measurement of respective wavefront aberrations of different partial arrangements (M1; M2; M3; M1, M3) of the optical elements.

An optical system includes a light source, an interferometer, and a detector. The interferometer includes a scanner and a lens system disposed downstream of the scanner. The scanner is configured to direct a portion of the optical beam along one of a plurality of different directions within a scanning range. The lens system is configured to project the portion of optical beam to an imaging area defined by a field of view of the optical system, the lens system comprising a first lens, wherein an aspect of the first lens is adjustable so as to render the field of view adjustable without adjusting the scanning range of the scanner. The detector is configured to receive a reflected portion of the optical beam that reflects from an object placed within the imaging area.

Interference fringes in a bullseye pattern are produced by a measurement module by interfering a flat reference beam with a spherical beam reflected by a sphere connected to the tip of a probe in point contact with a test object. The bullseye interferogram is registered at a detector and analyzed conventionally to produce a position measurement of the tip of the probe. A beam correction module is used to align the bullseye interferogram with the illumination axis of the measurement module. By combining at least three such measurement modules in a coordinate measurement machine, the three-dimensional position of the probe and of its point contact with the test object can be obtained from analysis of the bullseye interferograms registered by the detectors with high precision and greatly reduced Abbe error.

The Solid-State distinct-unidirectional photonic interferometer is an onboard opto-electronic navigational instrument that utilizes propagation of light within the instrument for continuously and independently, from other sources, detecting and measuring position, orientation, displacement, and rates of the displacement of an object in motion from within and from the motion itself.