Translations of an object in a plurality of different spatial directions are measured using a plurality of interferometers to detect interference with light that has been reflected from a diffusively reflective surface, preferably using diffuse reflection from the same planar surface to measure in each of the different spatial directions. At least the interferometers that measure translation in directions that are not perpendicular to the surface each comprises a single mode fiber and a collimator configured to transmit the outgoing light to the object successively through the single mode fiber and the collimator, and to collect reflection into the single mode fiber with the collimator both along a same beam direction. It has been found that, when reflection of a beam with a beam direction at an oblique angle to a diffusively reflective surface is used, the interference resulting from translation of the object is due substantially only to translation in the beam direction.

An Optical Coherence Tomography receiver may include prisms, polarizing beam splitters, reflectors, lenses, and a photodetector array arranged in a compact package. Sample and reference beams are combined into an interference beam and split in two. The two resulting interference beams are then split into two polarization sates each. The optical path lengths for both pairs of interference beams with the same polarization state are equal or nearly equal.

Methods, devices, and systems for processing information are disclosed. An example device may comprise a metastructure comprising a plurality of physical features configured to transform an analog signal according to a kernel of an integral equation. The device may comprise one or more waveguides coupled to the metastructure and configured to recursively supply a transformed analog output signal of the metastructure to an input of the metastructure to iteratively cause one or more transformed analog signals output from the metastructure to converge to an analog signal representing a solution to the integral equation.

Methods, devices, and systems for processing information are disclosed. An example device may comprise a metastructure comprising a plurality of physical features configured to transform an analog signal according to a kernel of an integral equation. The device may comprise one or more waveguides coupled to the metastructure and configured to recursively supply a transformed analog output signal of the metastructure to an input of the metastructure to iteratively cause one or more transformed analog signals output from the metastructure to converge to an analog signal representing a solution to the integral equation.

Techniques are described for monitoring the degradation of electrochemical cells. A battery monitoring system monitors, for each of one or more cells of a plurality of cells in a battery, an amount of mechanical deformation using one or more measuring devices. The battery monitoring system determines a number of cells of the plurality of one or more monitored cells for which the monitored amount of mechanical deformation exceeds a deformation threshold. The battery monitoring system determines whether the determined number of cells exceeds a threshold number of cells with an amount of mechanical deformation exceeding the deformation threshold. Responsive to determining the determined number of cells exceeds the threshold number of cells, the battery monitoring system sends a notification that the battery is degraded beyond an acceptable limit.

Techniques are described for monitoring the degradation of electrochemical cells. A battery monitoring system monitors, for each of one or more cells of a plurality of cells in a battery, an amount of mechanical deformation using one or more measuring devices. The battery monitoring system determines a number of cells of the plurality of one or more monitored cells for which the monitored amount of mechanical deformation exceeds a deformation threshold. The battery monitoring system determines whether the determined number of cells exceeds a threshold number of cells with an amount of mechanical deformation exceeding the deformation threshold. Responsive to determining the determined number of cells exceeds the threshold number of cells, the battery monitoring system sends a notification that the battery is degraded beyond an acceptable limit.

Retinal imaging systems and related methods employ a user specific approach for controlling the reference arm length in an optical coherence tomography (OCT) imaging device. A method includes restraining a user's head relative to an OCT imaging device. A reference arm length adjustment module is controlled to vary a reference arm length to search a user specific range of reference arm lengths to identify a reference arm length for which the OCT image detector produces an OCT signal corresponding to the retina of the user. The user specific range of reference arm lengths covers a smaller range of reference arm lengths than a reference arm length adjustment range of the reference arm length adjustment module.

The optical interference tomographic imaging device is provided with: a wavelength sweeping laser light source; a branching unit that branches light emitted from the wavelength sweeping laser light source to object light and reference light; an irradiation unit that scans a predetermined range by irradiating different positions on the surface of the measurement target object with the object light outputted from the branching unit; a measurement unit that, after irradiation on the measurement target object, generates information about a change in the interference light intensity ratio between the reference light and the object light scattered from the measurement target object; and a control unit that, on the basis of the information about the change in the interference light intensity ratio generated by the measurement unit, acquires structure data in the depth direction of the measurement target object.

The optical interference tomographic imaging device is provided with: a wavelength sweeping laser light source; a branching unit that branches light emitted from the wavelength sweeping laser light source to object light and reference light; an irradiation unit that scans a predetermined range by irradiating different positions on the surface of the measurement target object with the object light outputted from the branching unit; a measurement unit that, after irradiation on the measurement target object, generates information about a change in the interference light intensity ratio between the reference light and the object light scattered from the measurement target object; and a control unit that, on the basis of the information about the change in the interference light intensity ratio generated by the measurement unit, acquires structure data in the depth direction of the measurement target object.

An apparatus for adjusting a beam path for tracking an object includes an illumination unit to generate an illumination light beam, an optical unit with a beam expander optical unit and a beam deflection unit, the beam expander optical unit being configured to divergently expand the illumination light beam and the beam deflection unit being configured to deflect the illumination light beam spatially about two different axes of rotation, a detector unit to capture a light beam reflected by the object in response to an illumination by the illumination light beam and to generate a measurement signal, an evaluation and control unit to evaluate the measurement signal and configured to determine a manipulated variable for setting an effective focal length of the beam expander optical unit and/or for setting a spatial alignment of the beam deflection unit based on the information item in respect of the illumination of the object.