Abstract:
A portable system and method for analyzing biological tissue samples and detecting analytes associated with tissue oxygenation using a conformal filter. A conformal filter, which may comprise a tunable filter, is configured to filter interacted photons conforming to a spectral shape correlated with an analyte of interest. Conformal filter configurations may be selected by consulting a modified look-up table associated with an analyte. An iterative methodology may be used to calibrate a conformal design for an analyte of interest, refine a previous conformal filter design for an analyte of interest, and/or generate a new conformal filter design for an analyte of interest.
Abstract:
There is provided a method for referencing and correcting the beating spectrum generated by the interference of the components of a frequency comb source. The proposed method allows monitoring of variations of a mapping between the source and the beating replica. This can then be used to compensate small variations of the source in Fourier transform spectroscopy or in any other interferometry application in order to overcome the accuracy and measurement time limitations of the prior art. Constraints on source stability are consequently reduced.
Abstract:
Application of digital light processor (DLP) systems in an imaging ellipsometer or imaging polarimeter with a focusing means, sample and detector arranged to meet the Scheimpflug condition.
Abstract:
A system and method is provided for improved fluorescence decay time measurement. A digital heterodyning technique is disclosed in which a photon detector is sampled at a rate slightly faster than a digitally pulsed excitation signal. A resulting cross correlation frequency is low enough to be read by inexpensive electronics such as by a field programmable gate array. Phase information in the signal provides correlation with corresponding photon detections.
Abstract:
A method of detecting a target gas includes the step of traversing a target area with a gas-filter correlation radiometer having a field of view oriented towards the target area. The gas-filter correlation radiometer receives reflected radiation in a passband from the target area and produces gas-filter correlation radiometer signals from the received reflected radiation. A surface reflectivity spectral profile of the target area is determined. The presence of the target gas in the target area is then determined based upon the received reflected radiation and the surface reflectivity spectral profile of the target area.
Abstract:
A system and method is provided for improved fluorescence decay time measurement. A digital heterodyning technique is disclosed in which a photon detector is sampled at a rate slightly faster than a digitally pulsed excitation signal. A resulting cross correlation frequency is low enough to be read by inexpensive electronics such as by a field programmable gate array. Phase information in the signal provides correlation with corresponding photon detections.
Abstract:
An airborne/spaceborne oil spill detection method includes the step of providing a moderate-resolution-imaging-spectroradiometer and sensing the spectral reflections from two optical bands one of which is in the near inferred range. The spectral contrast shift from two adjacent areas of water are calculated and a warning issued when an oil spill or other contaminant is detected. A system for detecting an oil spill or other contaminant on the surface of water is also disclosed.
Abstract:
Application of digital light processor (DLP) systems in monochromator, spectrophotometer or the like systems to mediate selection of individual wavelengths, and/or to image elected regions of a sample in an imaging ellipsometer, imaging polarimeter, imaging reflectometer, imaging spectrophotometer, and/or to provide chopped beams.
Abstract:
A correlation spectrometer can detect a large number of gaseous compounds, or chemical species, with a species-specific mask wheel. In this mode, the spectrometer is optimized for the direct measurement of individual target compounds. Additionally, the spectrometer can measure the transmission spectrum from a given sample of gas. In this mode, infrared light is passed through a gas sample and the infrared transmission signature of the gasses present is recorded and measured using Hadamard encoding techniques. The spectrometer can detect the transmission or emission spectra in any system where multiple species are present in a generally known volume.
Abstract:
A method for determining the autocorrelation function q(τ) of an optical signal, including the steps of: determining the times (ti) of occurrence of pulses corresponding to photons: calculating, for a predetermined set of pulses (w), the function s(w)=Σie−jwti, where e−jwti=coswti+jsinwti, the summing-up being performed over all the received pulses determining square S(w) of the module of function s(w), and calculating the Fourier transform g(τ) of power spectrum S(w) for a predetermined set of time interval values.
Abstract translation:一种用于确定光信号的自相关函数q(τ)的方法,包括以下步骤:确定与光子相对应的脉冲的出现次数(ti):对于预定脉冲组(w)计算函数s (w)= SigmaΣ i = iΣ i = 0 iΣ i = 在所有接收到的脉冲上执行功能s(w)的模块的平方S(w),并计算预定的一组时间间隔值的功率谱S(w)的傅里叶变换g(τ)。