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.

A method of determining a displacement comprises: generating an interferometric superoscillatory field from coherent electromagnetic radiation, the interferometric superoscillatory field comprising an interference pattern between a reference field and a superoscillatory field; detecting with a detector a first set of intensity distributions of the interferometric superoscillatory field, each intensity distribution from a different polarisation state of the electromagnetic radiation; detecting with the detector a second set of intensity distributions of the interferometric superoscillatory field, each intensity distribution from the same polarisation states of the electromagnetic radiation as the first set of intensity distributions; extracting a first local wavevector distribution from the first set of intensity distributions and a second local wavevector distribution from the second set of intensity distributions; comparing the first local wavevector distribution and the second local wavevector distribution to identify any change in position of one or more features in the local wavevector distributions; and ascertaining that a lateral displacement has occurred between the interferometric superoscillatory field and the detector if a change in position is identified.

A splitting and recombining optical component with an increased field of view while maintaining or only minimally increasing the space requirements therefor is provided. Further, the combination of the changes in physical geometry and refractive index of the beam splitting and recombining optical device can increase the field of view of a system while maintaining, or even reducing, the mass of the system in which the present beam splitting and recombining optic may be utilized

A simultaneous phase-shift point diffraction interferometer and method for detecting wave aberration. The interferometer comprises an ideal spherical wave generation module, an optical system to be measured, an image plane mask, a polarization phase shift module, a two-dimensional polarization imaging photodetector and a data processing unit. Single photodetector is adopted to realize simultaneous detection of more than three phase shift interference patterns, and has the advantages that environmental interference suppression, a flexible optical path, high measurement accuracy, and calibration of system errors of the interferometer may be realized.

A non-confocal point-scan Fourier-domain optical coherence tomography, OCT, imaging system, comprising: a scanning system arranged to perform a two-dimensional point scan of a light beam across an imaging target, and collect light scattered by the imaging target; a light detector arranged to generate a detection signal based on an interference between a reference light and the light collected by the scanning system. The OCT imaging system further comprises hardware arranged to: generate complex volumetric OCT data of the imaging target based on the detection signal, the OCT data including a component which, when the OCT data is processed to generate an enface projection of the OCT data, provides a defocusing and/or distortion in the enface projection; and generate corrected OCT data by executing a correction algorithm which uses phase information in the OCT data to remove at least some of the component from the OCT data.

A laser interference device includes: a measurement mirror being movable in an X direction; a reference mirror disposed at a position different from a position of the measurement mirror in a Y direction; a beam splitter having a splitting surface that divides a laser beam into a measurement light and a reference light; a first light guide configured to guide the measurement light incident from the beam splitter and emit the measurement light toward the measurement mirror; and a second light guide configured to guide the reference light incident from the beam splitter and emit the reference light toward the reference mirror, in which a first distribution path formed by the first light guide and a second distribution path formed by the second light guide are mutually equal in a mechanical path length and an optical path length.

A laser interference device includes: a measurement mirror being movable in an X direction; a reference mirror disposed at a position different from a position of the measurement mirror in a Y direction; a beam splitter having a splitting surface that divides a laser beam into a measurement light and a reference light; a first light guide configured to guide the measurement light incident from the beam splitter and emit the measurement light toward the measurement mirror; and a second light guide configured to guide the reference light incident from the beam splitter and emit the reference light toward the reference mirror, in which a first distribution path formed by the first light guide and a second distribution path formed by the second light guide are mutually equal in a mechanical path length and an optical path length.

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 $\frac{2\pi }{N}$
phase-shifting interval (where, $N=2\left(\mathrm{fix}\left(\frac{\mathrm{ceil}\left(1/s\right)}{2}\right)+1\right),$
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.

A method of determining a displacement comprises: generating an interferometric superoscillatory field from coherent electromagnetic radiation, the interferometric superoscillatory field comprising an interference pattern between a reference field and a superoscillatory field; detecting with a detector a first set of intensity distributions of the interferometric superoscillatory field, each intensity distribution from a different polarisation state of the electromagnetic radiation; detecting with the detector a second set of intensity distributions of the interferometric superoscillatory field, each intensity distribution from the same polarisation states of the electromagnetic radiation as the first set of intensity distributions; extracting a first local wavevector distribution from the first set of intensity distributions and a second local wavevector distribution from the second set of intensity distributions; comparing the first local wavevector distribution and the second local wavevector distribution to identify any change in position of one or more features in the local wavevector distributions; and ascertaining that a lateral displacement has occurred between the interferometric superoscillatory field and the detector if a change in position is identified.

Provided are systems and methods for using laser interferometry to measure moving objects. Systems provided include laser interferometry systems comprising: a laser emitter configured to emit a laser beam; a beam splitter configured to split the emitted laser beam into a first split beam directed towards a deflector and a second split beam, wherein the first split beam comprises a first beam diameter and a second beam diameter, the first beam diameter being greater than the second beam diameter, and the second split beam comprises a third beam diameter and a fourth beam diameter, the third split beam diameter being greater than the fourth beam diameter; and a deflector configured to deflect the first split beam to intersect with the first split beam, wherein the first beam diameter and the third beam diameter are parallel.