The present disclosure relates to systems, vehicles, and methods relating to imaging and object detection using polarization-based detection of infrared light. An example system includes at least one infrared detector configured to detect infrared light corresponding to a target object within a field of view. The infrared light includes at least one of a first polarization or a second polarization. The system also includes a controller configured to carry out operations. The operations include receiving, from the at least one infrared detector, information indicative of infrared light corresponding to the target object. The operations also include determining, based on the received information, a polarization ratio corresponding to the target object. The polarization ratio comprises a first polarization intensity divided by a second polarization intensity. The operations also include determining, based on the polarization ratio, that the infrared light corresponding to the target object comprises direct light or reflected light.

The system and method for imaging having filter containing polarized elements, multispectral elements or both being oscillated in circular or linear motion so each individual pixel will view a scene thru the individual filters. The motion of the filter is synchronized with a frame rate of an imager. In one example this is accomplished by micro actuators. Each pixel sampling feeds a processor detection algorithm that determines if a multispectral/polarization signature is present in the scene.

The system and method for imaging having filter containing polarized elements, multispectral elements or both being oscillated in circular or linear motion so each individual pixel will view a scene thru the individual filters. The motion of the filter is synchronized with a frame rate of an imager. In one example this is accomplished by micro actuators. Each pixel sampling feeds a processor detection algorithm that determines if a multispectral/polarization signature is present in the scene.

A method of measuring optical properties of a specimen includes generating illumination light at a plurality of illumination wavelengths and, for each of the plurality of illumination wavelengths, directing the illumination light to impinge on the specimen, collecting sample light passing through the specimen, and detecting the collected sample light using a polarization state analyzer to form a set of polarization channels. The method also includes receiving a calibration tensor, converting the set of polarization channels for each of the illumination wavelengths into Stokes parameter maps using the calibration tensor, denoising the Stokes parameter maps, and deconvolving the Stokes parameter maps to provide density, anisotropy, and orientation measurements of the specimen. The method can multiplex intrinsic density, anisotropy, and orientation measurements of the specimen and density, anisotropy, and orientation measurements of labeled fluorescent molecules.

Methods, systems and devices are disclosed to detect and compensate wavefront errors associated with light that spans a large range of wavelengths and different polarization states. One example system includes an optical wavefront sensor that is positioned to receive input light after propagation through a turbulent medium, such as air or water or other liquids, and to detect a wavefront error associated with at least one spectral component of the received light that has a plurality of spectral components. The system further includes a wavefront compensator that is positioned to receive the input light and to simultaneously effectuate wavefront corrections for the plurality of spectral components of the input light based on the detected wavefront error.

Methods, systems and devices are disclosed to detect and compensate wavefront errors associated with light that spans a large range of wavelengths and different polarization states. One example system includes an optical wavefront sensor that is positioned to receive input light after propagation through a turbulent medium, such as air or water or other liquids, and to detect a wavefront error associated with at least one spectral component of the received light that has a plurality of spectral components. The system further includes a wavefront compensator that is positioned to receive the input light and to simultaneously effectuate wavefront corrections for the plurality of spectral components of the input light based on the detected wavefront error.

Systems and methods of performing a stress measurement of a chemically strengthened glass using a light-scattering polarimetry system include adjusting the intensity of a light beam from a light source in an illumination system using a rotatable half-wave plate and a first polarizer operably disposed between the light source and a rotating light diffuser that has a rotation time t.sub.R. The first polarizer is aligned with a second polarizer in a downstream optical compensator to have matching polarization directions by rotating the rotatable half-wave plate to a position where the exposure time t.sub.E falls within an exposure range t.sub.R≤t.sub.E. The method also includes performing an exposure using the exposure time t.sub.E to obtain the stress measurement. One or both of the half-wave plate and first polarizer can be tilted to avoid deleterious back-reflected light from entering the light source.

Systems and methods of performing a stress measurement of a chemically strengthened glass using a light-scattering polarimetry system include adjusting the intensity of a light beam from a light source in an illumination system using a rotatable half-wave plate and a first polarizer operably disposed between the light source and a rotating light diffuser that has a rotation time t.sub.R. The first polarizer is aligned with a second polarizer in a downstream optical compensator to have matching polarization directions by rotating the rotatable half-wave plate to a position where the exposure time t.sub.E falls within an exposure range t.sub.R≤t.sub.E. The method also includes performing an exposure using the exposure time t.sub.E to obtain the stress measurement. One or both of the half-wave plate and first polarizer can be tilted to avoid deleterious back-reflected light from entering the light source.

A system is described that combines spectropolarimetry with scatterometry. The system uses an annular mirror and liquid crystal devices to control the angle of the incident light cone, the polarization and wavelength, an imaging setup and one or more video cameras so that spectroseopic-polarimetric-scatterometric images can be grabbed rapidly. The system is also designed to incorporate additional imaging modes such as interference, phase contrast, fluorescence and Raman spectropolarimetric imaging.

Disclosed herein systems and methods of performing spoof resistant object recognition. In certain embodiments, a system for object recognition includes: an illumination device configured to illuminate an object; a sensor device, wherein the sensor device receives illumination light reflected off the object which includes polarization information; a processor; memory including programming executable by the processor to: calculate the polarization information from the illumination light; use the polarization information to determine whether the object is a real 3D object. It has been discovered that polarization information may be utilized to determine whether an object is a 3D object or a flat (2D) object. Thus, the polarization information may be utilized to differentiate from an image of a 3D object and a photograph of an object.