Abstract:
An apparatus and method are provided. In particular, at least one first electro-magnetic radiation may be provided to a sample and at least one second electro-magnetic radiation can be provided to a non-reflective reference. A frequency of the first and/or second radiations varies over time. An interference is detected between at least one third radiation associated with the first radiation and at least one fourth radiation associated with the second radiation. Alternatively, the first electro-magnetic radiation and/or second electro-magnetic radiation have a spectrum which changes over time. The spectrum may contain multiple frequencies at a particular time. In addition, it is possible to detect the interference signal between the third radiation and the fourth radiation in a first polarization state. Further, it may be preferable to detect a further interference signal between the third and fourth radiations in a second polarization state which is different from the first polarization state. The first and/or second electro-magnetic radiations may have a spectrum whose mean frequency changes substantially continuously over time at a tuning speed that is greater than 100 Tera Hertz per millisecond.
Abstract:
A spectral imaging apparatus includes: a spectral transmittance variable element having a spectral transmittance characteristics such that a transmittance periodically varies with wavelength and being capable of changing the variation period, for converting light from an object under observation into light having a plurality of peak wavelengths; a light extracting device for extracting, from the light having a plurality of peak wavelengths, light for imaging that contains a peak wavelength proximate to a predetermined command wavelength designated by a user and light for calibration that contains a peak wavelength other than the peak wavelength proximate to the command wavelength; an image sensor for capturing an image of the object under observation formed of the light for imaging; a detector for detecting, from the light for calibration, the peak wavelength other than the peak wavelength proximate to the command wavelength; and a control unit including, an operation processing section that calculates the peak wavelength that is proximate to the command wavelength and is contained in the light for imaging, from the peak wavelength that is other than the peak wavelength proximate to the command wavelength, is contained in the light for calibration and is detected by the detector, calculates an amount of shift between the peak wavelength proximate to the command wavelength as calculated and the command wavelength, and determines an amount of adjustment of the variation period on a basis of the amount of shift, and a drive processing section that drives the spectral transmittance variable element for changing the variation period.
Abstract:
A combination of a focusing means, and a filtering means which naturally adjusts the cross-sectional area of a beam of electromagnetic radiation passed to the focusing means as a function of wavelength, optionally as an element of an ellipsometer or polarimeter system.
Abstract:
A compact, ultra-sensitive, inexpensive NIR spontaneous Raman spectrometer is presented. High sensitivity is achieved by the use of a multi-pass cell configuration combined with the electromotive properties of silicon crystal surface. A thin layer of silicon oxide chemisorbs molecules, which stick to its surface without altering their spectroscopic signatures. This new Raman spectrometer may be used to detect less than 40 ng (≈0.5 n mol) of ammonium nitrate deposited on the silicon surface with the signal-to-noise ratio better than 50 during 0.1 s recording time and for an illuminated area of 2×10−8 m2. These results may be useful in many areas, for example the foundation of an extended project to record the dissolved NO3− ions in a large river such as the Mississippi.
Abstract:
A device for detecting gas concentrations includes a movable coded filter. An optical element is positioned to receive gas filtered light and spectrally separate the gas filtered light. A photo detector is positioned to receive the spectrally separated light through slits in the moveable coded filter to provide an AC signal representative of a selected gas.
Abstract:
An imaging spectrometer provides substantially simultaneous areal spectroscopy and image generation to provide improved analysis of possible skin cancer.
Abstract:
A miniaturized imaging system is provided that operates in multiple modes, including a coherent anti-stokes Raman scattering (CARS) mode. The imaging system includes: a laser delivery subsystem that generates an excitation signal; a scanning mechanism configured to receive the excitation signal from the laser delivery subsystem and direct the excitation signal through an optics subsystem onto a sample, such that the optics subsystem compensates for chromatic aberration in the excitation signal; and a dichroic mirror that receives emission from the sample in a backward direction and directs the emission along a collection path to a detector. The light source for the laser delivery subsystem may be a single femtosecond pulse laser.
Abstract:
This invention is to make the detection sensitivities as even as possible among a plurality of specimens to be inspected in an analyzer that leads light transmitted from the plurality of specimens to be inspected to a single spectrometer via optical fibers, the analyzer includes first and second light guide members provided for every first and second specimen to be inspected so as to lead the light obtained from each of the specimens to be inspected to a photo-detecting part, and light projection side end portions of a plurality of optical fiber elements composing the first and second light guide members are arranged in mixture.
Abstract:
A spectrophotometer includes a plurality of LEDs arranged in a circular array, each having a calibrated power input determined by the use of pulse width modulation and each having a unique wavelength band determined by the utilization of a unique fluorescent phosphor coating or lens. At least one of the LEDs comprising a phosphor-free high energy UV LED. Light reflected to the spectrophotometer is divided into predetermined wavelength ranges through the utilization of a linear variable filter and photo detectors wherein the analog signal from a photo detector is converted to a digital value through the use of auto-ranging gain technique.
Abstract:
A method for designing the spatial partition of a filter module used in an aperture-multiplexed imaging system. The filter module is spatially partitioned into filter cells, and the spatial partition is designed by considering data captured at the sensor in light of an application-specific performance metric.