Provided is a system for range detection including at least one beam source arrangement configured to provide illumination of certain coherence length, an optical arrangement, and a detection arrangement including at least one detector unit.

A system for sensing microbends and micro-deformations in three-dimensional space is based upon a distributed length optical fiber formed to include a group of offset cores disposed in a spiral configuration along the length of the fiber, each core including a fiber Bragg grating that exhibits the same Bragg wavelength. A micro-scale local deformation of the multicore fiber produces a local shift in the Bragg wavelength, where the use of multiple cores allows for a complete micro-scale modeling of the local deformation. Sequential probing of each core allows for optical frequency domain reflectometry (OFDR) allows for reconstruction of a given three-dimensional shape, delineating location and size of various microbends and micro-deformations.

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.

Methods and apparatus are presented for multichannel optical coherence tomography. Light from a wavelength tuneable or steppable optical source is separated into one or more sample beams and one or more reference beams, and the one or more sample beams directed onto a sample to form one or more interaction regions. A plurality of returning probe beams are collected and mixed with the one or more reference beams to form an interference pattern comprising a plurality of interferograms having at least two distinct carrier frequencies. The multichannel optical apparatus can be provided with polarisation discrimination by mixing the returning probe beams with two orthogonally polarised reference beams to form one or more interference patterns each comprising a plurality of interferograms having at least two distinct carrier frequencies. In preferred embodiments each interferogram has a distinct carrier frequency, which may be provided by ensuring that each returning probe beam has a distinct propagation angle with respect to a reference beam. Also presented is a means of generating a plurality of beamlets from a sample beam using a nonreciprocal optical splitter configured to split a beam propagating in a forwards direction into a plurality of beamlets, and to transmit without splitting a beam propagating in the reverse direction.

An OCT system for measuring a retina as part of an eye health monitoring and diagnosis system. The OCT system includes an OCT interferometer, where the interferometer comprises a light source or measurement beam and a scanner for moving the beam on the retina of a patient's eye, and a processor configured to execute instructions to cause the scanner to move the measurement beam on the retina in a scan pattern. The scan pattern is a continuous pattern that includes a plurality of lobes. The measurement beam may be caused to move on the retina by the motion of a mirror that intercepts and redirects the measurement beam. The mirror position may be altered by the application of a drive signal to one or more actuators that respond to the drive signal by rotating the mirror about an axis or axes.

An OCT system for measuring a retina as part of an eye health monitoring and diagnosis system. The OCT system includes an OCT interferometer, where the interferometer comprises a light source or measurement beam and a scanner for moving the beam on the retina of a patient's eye, and a processor configured to execute instructions to cause the scanner to move the measurement beam on the retina in a scan pattern. The scan pattern is a continuous pattern that includes a plurality of lobes. The measurement beam may be caused to move on the retina by the motion of a mirror that intercepts and redirects the measurement beam. The mirror position may be altered by the application of a drive signal to one or more actuators that respond to the drive signal by rotating the mirror about an axis or axes.

An exemplary system can be provided which can include, for example, a plurality of source arrangements configured to provide a plurality of electro-magnetic radiations to at least one of at least one sample or at least one reference structure, a first arrangement configured to receive a first radiation(s) from the reference structure(s), a second arrangement configured to receive a second radiation(s) from the sample(s), where a portion(s) of the second radiation(s) can be in an invisible spectrum, a third arrangement configured to combine the first radiation(s) and the second radiation(s) into a third radiation(s), and a fourth arrangement configured to convert the third radiation(s) into a further radiation in a visible spectrum based on the at least one portion.

Provided is a swept light source including one end surface coupled to a wavelength filter constituted of a diffraction grating and an end mirror via a light deflector and another end surface including a gain medium facing an output coupling mirror and which configures a laser cavity between the end mirror and the output coupling mirror, wherein a drive voltage having an AC voltage on which a DC bias voltage is superimposed is output from a control voltage source of the light deflector to an electrode pair of an electro-optic crystal, light is radiated from a light emitter to the electro-optic crystal, and incident light from the gain medium incident along an optical axis perpendicular to a direction of an electric field formed by the control voltage is deflected in a direction parallel to the electric field, so that wavelength sweeping is performed.

A method for determining characteristics of a test cavity, the method includes for each of a plurality of optical frequencies within a bandwidth of a tunable laser, measuring interference signals from the test cavity and a reference cavity having a known characteristic. The method includes determining values for the plurality of optical frequencies from the measured interference signals from the reference cavity and the known characteristic of the reference cavity, and determining the characteristic of the test cavity using the determined values of the plurality of optical frequencies.

An optical interrogation system, e.g., an OFDR-based system, measures local changes, of index of refraction of a sensing light guide subjected to a time-varying disturbance. Interferometric measurement signals detected for a length of the sensing light guide are transformed into the spectral domain. A time varying signal is determined from the transformed interferometric measurement data set. A compensating signal is determined from the time varying signal which is used to compensate the interferometric measurement data set for the time-varying disturbance. Further robustness is achieved using averaging and strain compensation. The compensation technique may be applied along the length of the light guide.