A system is provided for observing objects on a substrate which includes a light source that emits polarized light rectilinearly along a first direction, a holder that receives said substrate having a surface and includes objects, wherein at least one of the holder or the substrate are translucent or opaque, a detector that collects the backscattered light from the interaction between the light emitting by the light source and the objects, a polarization splitter and a quarter-wave plate wherein the polarization splitter and the quarter-wave plate are arranged so that the polarization splitter directs light towards the substrate through the quarter-wave plate, and wherein the light forms a beam and the system modifies the size of the beam. The system thus allows one to observe objects on a non-transparent substrate.

A micro object detection apparatus includes an optical system. The first optical system includes a first reflection region, a second reflection region, and a light reception element. The first reflection region has an ellipsoidal shape, and reflects scattered light scattered when irradiation light hits a particle to direct the scattered light to the light reception element, by utilizing two focal point positions of the ellipsoidal shape. The second reflection region reflects scattered light coming from the particle to direct the scattered light to the first reflection region, so that the scattered light is directed to the light reception element by utilizing the ellipsoidal shape of the first reflection region. The light flux diameter of the scattered light reflected by the second reflection region is larger than the particle, at the position of the particle at which the scattered light is generated.

An apparatus for spectroscopic tissue analysis is disclosed. The apparatus comprises: a light delivery system configured to direct an excitation signal on to a tissue sample; a light collection system configured to collect a backscattered signal comprising diffuse reflectance photons backscattered by the tissue sample; an imaging device; a spectrometer; an optical adaptor configured to direct a first portion of the backscattered signal to the imaging device and a second portion of the backscattered signal to the spectrometer; and an analysis system configured to apply polar decomposition to spectral image data of the tissue captured by the imaging device and the spectrometer and thereby derive polarization metrics for the tissue sample.

A defect inspection method includes irradiating a sample with laser, condensing and detecting scattered light beams, processing signals that detectors have detected and extracting a defect on a sample surface, and outputting information on the extracted defect. Detection of the scattered light beams is performed by condensing the scattered light beams, adjusting polarization directions of the condensed scattered light beams, mutually separating the light beams depending on the polarization direction, and detecting the light beams by a plurality of detectors. Extraction of the defect is performed by processing output signals from the detectors by multiplying each detection signal by a gain, discriminating between a noise and the defect, and detecting the defect.

Apparatus and associated methods relate to determining metrics of water particles in clouds by directing light pulses at a cloud and measuring a peak, a post-peak value and a high-frequency fluctuation of light signals reflected from the cloud. The light pulses include: a first pulse having circularly polarized light of a first wavelength; and a second pulse of a second wavelength. The reflected light signals include: a first reflected light signal having left-hand circular polarization of the first wavelength; a second reflected light signal having right-hand circular polarization of the first wavelength; and a third reflected light signal of the second wavelength. An extinction coefficient and a backscatter coefficient are determined based on the measured peak and post-peak slopes of the first and second reflected light signals. The measured high-frequency fluctuations of the three reflected light signals can be used to calculate cloud particle sizes.

Laser speckle microrheology is used to determine a mechanical property of a biological tissue, namely, an elastic modulus. Speckle frames may be acquired by illuminating a coherent light and capturing back-scattered rays in parallel and cross-polarized states with respect to illumination. The speckle frames may be analyzed temporally to obtain diffuse reflectance profiles (DRPs) for the parallel-polarized and cross-polarized states. A scattering characteristic of particles in the biological tissue may be determined based on the DRPs, and a displacement characteristic may be determined based at least in part on a speckle intensity autocorrelation function and the scattering characteristic. A size characteristic of scattering particles may be determined based on the DRP for the parallel polarization state. The mechanical property may be calculated using the displacement and size characteristics.

Systems and methods are provided for measuring spectral hemispherical reflectance. One embodiment is a system that includes a laser that emits a beam of light, and an optical chopper disposed between the laser and a sample. The chopper blocks the beam while the chopper is at a first angle of rotation, redirects the beam along a reference path while the chopper is at a second angle of rotation, and permits the beam to follow a sample path through the chopper and strike the sample while the chopper is at a third angle of rotation. The system also includes a hollow sphere that defines a slot through which the sample path and reference path enter the sphere. The hollow sphere includes a spectral hemispherical reflectance detector, a mount that receives the sample at the sphere, and an actuator that rotates the sphere about an axis that intersects the sample.

A method for assessing the condition of a tissue sample includes the steps of: 1. illuminating the sample with incident electromagnetic radiation exhibiting P polarization types, 2. for each of the P polarization types, inspecting the scattered incident radiation for at least one and possibly all of Q polarization types; 3. establishing a transfer function M relating the intensity of the P polarization types of the incident radiation to the intensity of the polarization types for which the scattered radiation was inspected; 4. comparing the established transfer function to one or more reference transfer functions; and 5. reaching a conclusion about the condition of the tissue sample based on the comparison.

System and method for determining a viscoelastic modulus of a sample with the use of optical data and an average size of light-scattering particles, of such sample, that has been derived from the optical data in reliance of angular dependence of a radiant flux profile determined from laser speckles formed by the sample and, in required, on a refractive index mismatch between light-scattering particles and sample medium hosting such particles. The determination is optionally carried out by taking into account at least one of absorption coefficient and reduced scattering coefficient of the sample, which are also determined from the same optical data. Laser speckle may be formed for different combinations of polarization states of sample-illuminating light and detected light and/or different wavelengths to account for polydisperse nature of the sample.

A device for imaging one dimension nanomaterials is provided. The device includes an optical microscope with a liquid immersion objective, a laser device, and a spectrometer. The laser device is configured to provide an incident light beam with a continuous spectrum. The spectrometer is configured to obtain spectral information of the one dimensional nanomaterials.