A waveguide interferometer includes a multicore fiber used a multicore waveguide, where the multicore waveguide includes a coupler section formed by tapering a portion of the multicore waveguide so that one core though which a light source is fed is optically coupled to another core that is terminated differently that the core into which the source signal is provided. The terminations respond differently upon being exposed to an environmental condition or substance, and the difference in response to the environmental condition or substance results in a shift in interference of the light reflected back through the multicore waveguide, which is detected with a detector on the same side of the multicore waveguide as the light source.

Aspects of the present disclosure describe Rayleigh fading mitigation via short pulse coherent distributed acoustic sensing with multi-location beating-term combination. In illustrative configurations, systems, methods, and structures according to the present disclosure employ a two stage modulation arrangement providing short interrogator pulses resulting in a greater number of sensing data points and reduced effective sectional length. The increased number of data points are used to mitigate Rayleigh fading via a spatial combining process, multi-location-beating combining (MLBC) which uses weighted complex-valued DAS beating results from neighboring locations and aligns phase signals of each of the locations, before combining them to produce a final DAS phase measurement. Since Rayleigh scattering is a random statistic, the MLBC process allows capture of different statics from neighboring locations with correlated vibration/acoustic signal. The combined DAS results minimize a total Rayleigh fade, in both dynamic fading and static fading scenarios.

Interferometric speckle visibility spectroscopy methods, systems, and non-transitory computer readable media for recovering sample speckle field data or a speckle field pattern from an off-axis interferogram recorded by one or more sensors over an exposure time and determining sample dynamics of a sample being analyzed from speckle statistics of the speckle field data or the speckle field pattern.

A method and an apparatus are directed to characterizing a continuously moving 3D object via interferometry-based scanning. The method includes repeatedly forming several depth characterizations of the 3D object along respective scan lines of a plurality of scan lines on the surface of the 3D object. During this scanning, the 3D object is undergoing its continuous motion. The method further includes combining the determined depth characterization along the scan lines of the plurality of scan lines to form a depth map representing at least a depth of a portion associated with a location on the surface of the 3D object in the third direction on a grid of locations arranged in the first and second directions. Forming the depth characterizations includes scanning a frequency-dispersed pulsed optical signal in a first direction across the continuously moving 3D object, said 3D object moving in a second direction substantially orthogonal to the first direction. The scanned optical signal forming scan lines on a surface of the 3D object in a third direction substantially orthogonal to the first direction and the second direction.

The present disclosure is directed toward low-coherence interferometry imaging systems comprising a common-path interferometer that is at least partially integrated as part of a planar lightwave circuit is disclosed. Imaging systems in accordance with the present disclosure are implemented in integrated optics without the inclusion of highly wavelength-sensitive components. As a result, they exhibit less wavelength dependence than PLC-based interferometers of the prior art. Further, common-path interferometer arrangements in accordance with the present disclosure avoid polarization and wavelength dispersion effects that plague prior-art PLC-based interferometers. Still further, an integrated common-path interferometer is smaller and less complex than other integrated interferometers, which makes it possible to integrate multiple interferometers on a single chip, thereby enabling multi-signal systems, such as plane-wave parallel OCT systems.

There are provided devices, systems and methods utilizing interferometric retro-reflection displacement/vibration meter. In particular, there are provided laser interferometer devices, systems and methods for measuring three-axis small angle displacements and vibrations of a body.

A gyroscope of the present invention includes a moving standing light wave generator to generate three moving standing light waves, an atomic beam source to continuously generate an atomic beam in which individual atoms are in the same state, an interference device that exerts a Sagnac effect through interaction between the atomic beam and the three moving standing light waves and a monitor to detect angular velocity or acceleration by monitoring an atomic beam from the interference device. The atoms are alkaline earth metal atoms, alkaline earth-like metal atoms, stable isotopes of alkaline earth metal atoms or stable isotopes of alkaline earth-like metal atoms.

Various optical systems equipped with diode laser light sources are discussed in the present application. One example system includes a diode laser light source for providing a beam of radiation. The diode laser has a spectral output bandwidth when driven under equilibrium conditions. The system further includes a driver circuit to apply a pulse of drive current to the diode laser. The pulse causes a variation in the output wavelength of the diode laser during the pulse such that the spectral output bandwidth is at least two times larger the spectral output bandwidth under the equilibrium conditions.

An ophthalmic imaging apparatus includes: a detector arranged to detect, as an interference signal, interference light resulting from returning light and reference light, the returning light being light from an object to be inspected to which measurement light is radiated, the reference light corresponding to the measurement light; a converter arranged to convert the detected interference signal that is an analog signal to a digital signal; and an arithmetic processing unit configured to generate a tomographic image of the object to be inspected by using the converted interference signal. The arithmetic processing unit uses a plurality of components obtained from the converted interference signal to generate the tomographic image, the plurality of components including a component having a frequency higher than a Nyquist frequency of the converter and a component having a frequency lower than the Nyquist frequency of the converter.

An electro-optical system has a laser drive electronic circuit, a laser light source and an optical interferometer, forming a closed loop. The laser drive electronic circuit is arranged to receive a reference frequency as input, and a beat frequency as feedback. The laser drive electronic circuit generates a drive output based on a phase difference between the reference frequency and the beat frequency. The optical interferometer, coupled to the laser light, generates optical energy at the beat frequency.