A method for multi-spectral scattering-matrix tomography includes a step of splitting an input light signal into an incident light signal and a reference light signal. The sample light signal is directed to a sample in either a reflection configuration or a transmission configuration such that an output light signal includes light scattered from or transmitted through the sample. The incident signal and the reference light signal are directed to a camera angled to allow for amplitude and phase to be calculated by off-axis holography. A total light signal is measured with a camera that is a coherent sum of the reference light signal and the output signal. The total light signal for each light frequency and each incident angle are collected as collected total light signal data. A computing device derives an image of the sample from a calculated reflection matrix or transmission matrix or both of them.

A method for determining a retardance of a layer of a sample. The method includes: transmitting a first portion of a polarized light to a sample arm of an optical system and a second portion of the polarized light to a reference arm of the optical system; combining first return light returned from the sample arm and second return light from the reference arm; detecting, using a detector, the combined light along a first polarization state and a second polarization state to produce polarization data, the second polarization state being different from the first polarization state; determining, using a processor coupled to the detector, polarization states of light returning from upper and lower surfaces of a layer of the sample based on detecting the combined light; and determining, using the processor, a retardance of the layer of the sample based on the determined polarization states.

A method for infrared chemical imaging through nondegenerate two-photon absorption includes a step of providing pulsed or continuous wave radiation having pumping photons at near-infrared wavelength and providing pulsed or continuous wave radiation that having mid-infrared photons at a mid-infrared wavelength with peak intensities less than 50 W/cm.sup.2. The mid-infrared photons are directed onto a target sample. The method also includes a step of spatially and temporally overlapping the mid-infrared photons with the pumping photons. The mid-infrared photons and the pumping photons are directed onto a camera having an array or matrix of imaging devices. Characteristically, the sum of photon energy for each temporally and spatially overlapping mid-infrared photons and pumping photons is greater than or equal to the bandgap energy.

An imaging system for cell-based therapies is provided. The imagining system includes one or more optical tags configured for insertion into a cell or biological tissue, an excitation light source configured to illuminate the one or more optical tags; a detector configured to measure optical emission of the one or more optical tags; an imaging subsystem configured to determine a three-dimensional location of each of the one or more optical tags in the cell or biological tissue; and a controller in electrical communication with the excitation light source, the detector, and the imaging subsystem. Each of the one or more optical tags has a contrasting feature and includes a fluorescent material. The contrasting feature may be defined by at least one of a refractive index, shape, color, and laser emission of each optical tag of the one or more optical tags.

An apparatus for performing diffuse optical imaging of a patient, said apparatus comprising: a computer; at least one sensor module comprising at least one optical source, at least one photodetector, and calibration data specific to said at least one sensor module; means for communicating between said computer and said at least one sensor module; means for automatically accessing said calibration data; and means for adjusting said apparatus in order to produce calibrated measurements.

A device for optical detection of analytes in a sample includes at least two optoelectronic components. The optoelectronic components include at least one optical detector configured to receive a photon and at least one optical emitter configured to emit a photon. The at least one optical emitter includes at least three optical emitters disposed in a flat, non-linear arrangement, and the at least one optical detector includes at least three optical detectors disposed in a flat, non-linear arrangement. The at least three optical emitters and the at least three optical detectors include at least three different wavelength characteristics.

A method and device for determining the depth and fluorophore concentration of a fluorophore concentration below the surface of an optically absorbing and scattering medium suitable for use in fluorescence-based surgical guidance such as in tumor resection is described. Long-wavelength stimulus light us used to obtain deep tissue penetration. Recovery of depth is performed by fitting measured modulation amplitudes for each spatial frequency to precomputed modulation amplitudes in a table of modulation amplitudes indexed by optical parameters and depth.

A surgical suturing tracking system is disclosed. The surgical suturing tracking system is configured to detect and guide a suturing needle during a surgical suturing procedure. The surgical suturing track system comprises a control circuit configured to predict a path of a needle suturing stroke after receiving an input from a clinician, detect an embedded tissue structure, and assess proximity of the predicted path and the detected embedded tissue structure.

Modulation-encoded light, using different spectral bin coded light components, can illuminate a stationary or moving (relative) target object or scene. Response signal processing can use information about the respective different time-varying modulation functions, to decode to recover information about a respective response parameter affected by the target object or scene. Electrical or optical modulation encoding can be used. LED-based spectroscopic analysis of a composition of a target (e.g., SpO2, glucose, etc.) can be performed; such can optionally include decoding of encoded optical modulation functions. Baffles or apertures or optics can be used, such as to constrain light provided by particular LEDs. Coded light illumination can be used with a focal plane array light imager receiving response light for inspecting a moving semiconductor or other target. Encoding can use orthogonal functions, such as an RGB illumination sequence, or a sequence of combinations of spectrally contiguous or non-contiguous colors.

An inspection system (1600), a lithography apparatus, and an inspection method are provided. The inspection system (1600) includes an illumination system (1602), a detection system (1606), and processing circuitry (1622). The illumination system generates a first illumination beam (1610) at a first wavelength and a second illumination beam (1618) at a second wavelength. The first wavelength is different from the second wavelength. The illumination system irradiates an object (1612) simultaneously with the first illumination beam and the second illumination beam. The detection system receives radiation (1620) scattered by a particle (1624) present at a surface (1626) of the object at the first wavelength. The detection system generates a detection signal. The processing circuitry determines a characteristic of the particle based on the detection signal.