Systems and methods for reducing fluorescence and systematic noise in time-gated spectroscopy are disclosed. Exemplary methods include: a method for reducing fluorescence and systematic noise in time-gated spectroscopy may comprise: providing first light using an excitation light source; receiving, by a detector, first scattered light from a material responsive to the first light during a first time window; detecting a peak intensity of the first scattered light; receiving, by the detector, second scattered light from the material responsive to the first light during a second time window; detecting a peak intensity of the second scattered light; recovering a spectrum of the material by taking a ratio of the peak intensity of the first scattered light and the peak intensity of the second scattered light; and identifying at least one molecule of the material using the recovered spectrum and a database of identified spectra.

A method and apparatus for determining a level of background fluorescent light produced during photometric interrogation of a sample is provided. The method includes applying an excitation light to a sample using a laser at a plurality linewidths different from one another, the excitation light at each of the plurality of different linewidths applied at an excitation wavelength operable to cause emission of light from the sample, the light emitted from the sample including Raman scattered light and background fluorescent light; detecting light emitted from the tissue sample at each of the plurality of linewidths using a detector and producing light signals representative of the detected light; and determining a level of the background fluorescent using the light signals representative of the detected light for each of the plurality of different linewidths.

The present invention relates to a method for evaluating the thermal expansion properties of a titania-containing glass body. On the basis of measured values, obtained at a certain temperature, for a physical parameter that changes depending on the titania concentration and a physical parameter that changes depending on the fictive temperature, the thermal expansion coefficient of the titania-containing silica glass body and the slope of the thermal expansion coefficient are calculated using a linear relational expression represented by a plurality of physical properties. The thermal expansion properties of the titania-containing silica glass body are evaluated on the basis of the calculated thermal expansion coefficient and thermal expansion coefficient slope.

Systems and methods for reducing fluorescence and systematic noise in time-gated spectroscopy are disclosed. Exemplary methods include: a method for reducing fluorescence and systematic noise in time-gated spectroscopy may comprise: providing first light using an excitation light source; receiving, by a detector, first scattered light from a material responsive to the first light during a first time window; detecting a peak intensity of the first scattered light; receiving, by the detector, second scattered light from the material responsive to the first light during a second time window; detecting a peak intensity of the second scattered light; recovering a spectrum of the material by taking a ratio of the peak intensity of the first scattered light and the peak intensity of the second scattered light; and identifying at least one molecule of the material using the recovered spectrum and a database of identified spectra.

Systems and methods for reducing fluorescence and systematic noise in time-gated spectroscopy are disclosed. Exemplary methods include: a method for reducing fluorescence and systematic noise in time-gated spectroscopy may comprise: providing first light using an excitation light source; receiving, by a detector, first scattered light from a material responsive to the first light during a first time window; detecting a peak intensity of the first scattered light; receiving, by the detector, second scattered light from the material responsive to the first light during a second time window; detecting a peak intensity of the second scattered light; recovering a spectrum of the material by taking a ratio of the peak intensity of the first scattered light and the peak intensity of the second scattered light; and identifying at least one molecule of the material using the recovered spectrum and a database of identified spectra.

A Raman spectrum inspection apparatus is provided, including: a exciting light source configured to emit an exciting light to a sample to be inspected; an optical device configured to collect an optical signal from a position, which is irradiated by the exciting light, of the sample to be inspected; and a spectrometer configured to generate a Raman spectrum of the sample to be inspected from the received optical signal, wherein an excitation optical path in which the exciting light passes from the exciting light device to the sample to be inspected and a detection optical path in which the optical signal received by the spectrometer passes from the sample to be inspected to the spectrometer are separated from each other.

The present invention relates to a highly portable, highly flexible standard of distance chemical detector such as can be used, for example, for standoff detection of explosives. Aspects of the invention include techniques for portability compactness and ways to diminish influence of fluorescence on Raman spectroscopy. Additional features can include a compact imaging spectrometer, a wirelessly connected smart device for user interface, and an auto-focus/range finder.

An apparatus for identifying materials. The apparatus includes a laser device adapted to produce monochromatic light in the wavelength range of about 400 nm to about 425 nm, a first set of optical components for focusing the laser light on a material sample positioned on a sample stage, a second set of optical components for transmitting light reflected from the material sample, and a spectrograph adapted to receive light reflected from the material sample via at least part of the second set of optical components and adapted to collect data in the Raman shift range of about 100 cm1 to about 1400 cm1. The first set of optical components includes a fiber optic cable adapted to transmit the laser light to the material sample. The second set of optical components includes an objective lens having an opening adapted to receive the fiber optic cable.

A compact, portable Raman spectrometer makes fast, sensitive standoff measurements at little to no risk of eye injury or igniting the materials being probed. This spectrometer uses differential Raman spectroscopy and ambient light measurements to measure point-and-shoot Raman signatures of dark or highly fluorescent materials at distances of 1 cm to 10 m or more. It scans the Raman pump beam(s) across the sample to reduce the risk of unduly heating or igniting the sample. Beam scanning also transforms the spectrometer into an instrument with a lower effective safety classification, reducing the risk of eye injury. The spectrometer's long standoff range automatic focusing make it easier to identify chemicals through clear and translucent obstacles, such as flow tubes, windows, and containers. And the spectrometer's components are light and small enough to be packaged in a handheld housing or housing suitable for a small robot to carry.

A collection optics system for a spectrometer and a Raman spectral system including the collection optics system is provided. The collection optics system is configured to selectively collect a Raman signal from scattered light output from a target object, the collection optics system includes a non-imaging collection unit configured to collect the Raman signal and output the Raman signal, the non-imaging collection unit including an entrance surface on which the scattered light is incident and an exit surface through which the Raman signal is output, and a Raman filter provided on a portion of the entrance surface of the non-imaging collection unit and configured to block the scattered light including a fluorescence signal. Therefore, the collection optics system may suppress reception of the fluorescence signal of the scattered light and selectively collect the Raman signal.