Apparatus are described herein related to augmenting human vision by means of adaptive polarization filter grids. A preferred embodiment is described as smart sunglasses, realized as see through head mountable device (HMD) configured to reduce glare originating from polarized light. Each eyeglass of the HMD is associated with a grid comprising a plurality of dynamically configurable polarization filters placed in the path of the light. A polarization analyzer module analyzes the polarization characteristics of a field of view and performs an optimization calculation. The polarization analyzer controls the said grid via a controller module in such a way that the filter state of each grid element can be addressed separately. The grid of polarization filters causes the polarization characteristics of the incident light to be adapted in such a way as to reduce glare and/or to provide a user of the said head mountable device with an enhanced visual perception of the field of view. The user of the described head mountable device has the option of selection between a plurality of polarization enhancement modes, such as horizontal or vertical polarization filtering only or a hybrid mode combining both horizontal and vertical polarization filtering on an individual basis for each grid element. Additionally smart window and smart mirror embodiments of the described adaptive polarization filter grids are introduced.

A method and apparatus are disclosed for measuring polarization of electromagnetic illumination. The method includes the steps of modulating a polarization state of illumination received from a target object to generate modulated intensity illumination, selectively measuring an intensity of the modulated intensity illumination by periodically gating an exposure of an imaging device to the modulated intensity illumination at a first gating frequency; responsive to the measured intensity, determining polarization parameters of the received illumination, and generating image data corresponding to the target object with a plurality of the polarization parameters, wherein the illumination from the target object is modulated in accordance with a first frequency and the first gating frequency is associated with and synchronized with at least the first frequency.

A photo-acoustic polarimetric remote sensing apparatus includes a telescope that directs visible light photons from an object. A polarizing beam splitter is in optical alignment with the telescope. The polarizing beam splitter has first and second pathways corresponding to first and second polarization states, respectively. The first and second pathways are substantially perpendicular. A first photodetector is in optical alignment with the first pathway, and a second photodetector is in optical alignment with the second pathway. At least one processor is in communication with the first and second photodetectors. The at least one processor generates a signal corresponding to a degree of linear polarization of the photons over time, and the signal is indicative of an acoustic signature of the object.

The system includes a modulatable illumination source configured to illuminate a surface of a sample disposed on a sample stage, a detector configured to detect illumination emanating from a surface of the sample, illumination optics configured to direct illumination from the modulatable illumination source to the surface of the sample, collection optics configured to direct illumination from the surface of the sample to the detector, and a modulation control system communicatively coupled to the modulatable illumination source, wherein the modulation control system is configured to modulate a drive current of the modulatable illumination source at a selected modulation frequency suitable for generating illumination having a selected coherence feature length. In addition, the present invention includes the time-sequential interleaving of outputs of multiple light sources to generate periodic pulse trains for use in multi-wavelength time-sequential optical metrology.

A combination of a focusing element, and a filtering element which naturally adjusts the cross-sectional area of a beam of electromagnetic radiation passed through the focusing element as a function of wavelength over a specified range of wavelengths, wherein the filtering element is not uniform, but rather varies as a selection from the group consisting of: optical density and/or thickness is greatest near the center thereof; and optical density and/or thickness is smallest near the center thereof;
and can demonstrate neutral density characteristics outside the specified range of wavelengths. The combination of a focusing element, and a filtering element can optionally be present in an ellipsometer or polarimeter system.

An photosensitive device, the sensor comprising: a plurality of photosensitive units distributed in an array, each photosensitive unit configured to receive and convert light signal, wherein the photosensitive unit comprises a detecting element and a polarizer, the detecting element comprises a carbon nanotube structure comprising a plurality of carbon nanotubes oriented along the same direction, and the polarizer is configured to generate polarized light to irradiate a part surface of the carbon nanotube structure; a measuring device configured to measure temperature differences or potential differences generated in the carbon nanotube structure by irradiating; a data processor configured to analyze and calculate the potential differences or the temperature differences to obtain the wavelength of the light signal.

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 spectroscopic-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.

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 spectroscopic-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.

In some embodiments, a collection system of a semiconductor metrology tool includes a chuck to support a target from which an optical beam is reflected and an aperture mask to provide an adjustable aperture for the reflected optical beam. The aperture mask includes a plurality of opaque plates with adjustable positions. The collection system also includes a spectrometer to receive the reflected optical beam. The aperture mask is situated between the chuck and the spectrometer along the optical axis.

In some embodiments, a collection system of a semiconductor metrology tool includes a chuck to support a target from which an optical beam is reflected and an aperture mask to provide an adjustable aperture for the reflected optical beam. The aperture mask includes a plurality of opaque plates with adjustable positions. The collection system also includes a spectrometer to receive the reflected optical beam. The aperture mask is situated between the chuck and the spectrometer along the optical axis.