Methods, apparatuses, and systems for detecting and classifying individual airborne biological and non-biological particles, in real time, based on particle size and polarized elastic scatter. Auto-fluorescence content may also be used along with particle size and polarized elastic scatter for further orthogonal classification. With polarized elastic scattering, the degree of linear or circular depolarization produced from particle morphology, refractive index, internal asymmetric structures and molecular optical activity can be used for classifying individual airborne particles. Alternatively, circular intensity differential scattering (CIDS) or linear intensity differential scattering (LIDS) can be used to discriminate individual particles.

Various aspects are directed to systems and methods for assessing neural activity of a neural region having multiple subfields. In certain embodiments, a method includes evoking a cellular electrical response in at least one subfield due to neural activity in the neural region, capturing image data of the electrical response at a level sufficiently detailed in space and time to differentiate between polarization-based events of two respective portions of the subfield, and then assessing neural activity by correlating space and time information, from the captured data, for the two respective portions of the sub-field. Other more specific aspects of the invention involve different preparation and neural stimulation approaches which can vary depending on the application.

Photoluminescence from a sample detector is detected using an array of photo-sensitive detectors. At least one first photo-sensitive detector of the array is provided with a first type of linear polarization filter and at least one second photo-sensitive detector is provided with a second type of linear polarization filter. The first type of linear polarization filter has a plane of polarization which is at angled with respect to a plane of polarization of said second type of polarization filter.

A light source having first and second wire-grid polarizers and a laser that emits a beam of linearly polarized light that is characterized by a propagation direction is disclosed. The first wire-grid polarization filter is characterized by a first linear polarization pass direction and a first actuator for causing the first linear polarization pass direction to rotate relative to the beam of linearly polarized light. The second wire-grid polarization filter is characterized by a second linear polarization pass direction and a second actuator for causing the second linear polarization pass direction to rotate relative to the beam of linearly polarized light. A controller sets the first and second linear polarization pass directions to provide linearly polarized light having a specified polarization direction.

A device, a method and a system for optically determining particle properties, in particular size and reflectivity. The device includes at least one light source assembly having at least one light source, a polarizer assembly, at least one sample holderwhich can be illuminated by the least one light source assemblyfor accommodating particle preparations to be investigated, at least one analyzer assembly, and at least one imaging device with at least one color-resolving matrix image sensor. The device is designed to guide light reflected by a particle preparation and having a color-coded polarization to the at least one matrix image sensor.

The invention describes a device (1) for characterizing the rough profile of a tissue sample comprising: a laser source (2) that illuminates the surface (100) of the tissue; a photodetector (3) that receives the light backscattered by the surface (100) of the tissue; and further a displacement means (4) configured to alternate between a first position wherein a rotating ground glass (5) is disposed within the path of the laser beam towards the surface (100), a second position wherein a rotating half wave blade (6) is disposed within the path of the laser beam towards the surface (100); and a third position wherein within the path of the laser beam towards the surface (100) neither the ground glass plate (5) nor the half wave blade (6) are arranged, or the half wave blade (6) is arranged in a fixed non-rotating position.

A light source having first and second wire-grid polarizers and a laser that emits a beam of linearly polarized light that is characterized by a propagation direction is disclosed. The first wire-grid polarization filter is characterized by a first linear polarization pass direction and a first actuator for causing the first linear polarization pass direction to rotate relative to the beam of linearly polarized light. The second wire-grid polarization filter is characterized by a second linear polarization pass direction and a second actuator for causing the second linear polarization pass direction to rotate relative to the beam of linearly polarized light. A controller sets the first and second linear polarization pass directions to provide linearly polarized light having a specified polarization direction.

Methods, devices and systems for estimating polarization characteristics of materials based on partial polarimetry are described. One example method for estimating polarization characteristics of a material includes illuminating the material with incident light, which can be unpolarized or have a particular polarization state. Two polarimetric measurements are conducted based on the interaction of the incident light with the material. The two polarimetric measurements detect light having orthogonal polarization states, and the interaction of the incident light with the material includes a depolarizing interaction. The method additionally includes determining an estimated coherency matrix eigenvalue and an estimated Mueller matrix throughput parameter using the first and the second polarimetric measurements, and determining an estimate of a full depolarizing Mueller matrix by extrapolating a reduced-rank Mueller matrix to obtain all sixteen elements of the depolarizing Mueller matrix that identifies the polarization characteristics of the material.