Abstract:
A Raman spectroscopy based system and method for examination and interrogation provides a method for rapid and cost effective screening of various protein-based compounds such as bacteria, virus, drugs, and tissue abnormalities. A hand-held spectroscope includes a laser and optical train for generating a Raman-shifting sample signal, signal processing and identification algorithms for signal conditioning and target detection with combinations of ultra-high resolution micro-filters and an imaging detector array to provide specific analysis of target spectral peaks within discrete spectral bands associated with a target pathogen.
Abstract:
An optical system of a high-resolution imaging spectrograph intended for deep ultraviolet Raman spectroscopy, including an entrance aperture constituted by a slit, followed by a collimating objective, with a dispersive element located between the collimating objective and the subsequent focusing objective is provided. A multichannel radiation detector is arranged behind the focusing objective. The collimating objective is formed at least by a main mirror, wherein the focussing objective is formed by a set of lenses. The dispersion element is formed at least by one diffraction grating 4 and/or an optical prism.
Abstract:
A multimode local probe microscope having a resonator, a first electrode, and a second electrode, an excitation source adapted to generate mechanical resonance in the resonator, a metal tip fastened to the resonator, movement mechanism for imparting relative movement between the local probe and a sample and adapted to bring the end of the tip to within a distance Z lying in the range 0 to 100 nm, and detector for detecting at least one electrical signal representative of friction forces at the terminals of said electrodes. The metal tip is electrically connected to the output second electrode and the microscopy apparatus includes amplifier and filter for amplifying and filtering signals relating to the friction forces and to the tunnelling current in a single electronic circuit, and configured for regulating the distance Z between the end of the tip and the surface of the sample.
Abstract:
The present disclosure concerns a method and detector (10) for detecting an analyte (1) in a sample volume (2), such as nitrosamine in an amine solvent. The method comprises measuring a resonance Raman spectrum (I1) with a first light beam (P1) matching an electronic transition of the analyte (1). The detection of the analyte is enhanced by measuring an off-resonance Raman spectrum (I2) using a second light beam (P2) that is shifted in wavelength at least 10 nm away from the electronic resonance. The resonance Raman signal (S1) of the analyte (1) is isolated from the background (Q1, Q2) by a difference analysis between the resonance and off-resonance Raman spectra (I1, I2). The method and detector (10) can be employed for detecting nitrosamine in a carbon capture process or plant (20) that employs an amine solvent.
Abstract:
This invention is within the technical field of corundum appraisal, and it involves an examination method to determine whether corundum has undergone beryllium diffusion treatment. Procedurally, a highly sensitive Raman spectrometer (S/N>10,000) is used to scan and examine the samples. The spectrometer is fitted with a tailor-made probe having a large facula and surface area. Specially developed software is then used to perform an intensity correction and a background elimination to obtain a specific Raman spectral range (250-120 cm-1) with the corrected intensity and a smooth baseline. The corrected and standardized Raman characteristic peak at 804 cm-1 (side-band) is used as a basis to determine whether the corundum has undergone beryllium diffusion treatment. This invention method has the advantages of being non-destructive, simple, fast, and practical. Also, it can accurately determine whether corundum has been treated.
Abstract:
Disclosed herein is a system (10) for measuring light induced transmission or reflection changes, in particular due to stimulated Raman emission. The system comprises a first light source (12) for generating a first light signal having a first wavelength, a second light source (14) for generating a second light signal having a second wavelength, an optical assembly (16) for superposing said first and second light signals at a sample location (18), and a detection means (24) for detecting a transmitted or reflected light signal, in particular a stimulated Raman signal caused by a Raman-active medium when located at said sample location. Here in at least one of the first and second light sources (12, 14) is one or both of actively controllable to emit a time controlled light pattern or operated substantially in CW mode and provided with an extra cavity modulation means (64) for generating a time controlled light pattern. The detection means (24) is capable of recording said transmitted or reflected light signal, in particular stimulated Raman signal, as a function of time.
Abstract:
An autofocus Raman spectrometer system includes a laser probe assembly, a microprocessor, adjustable stages and a driving means. The laser probe assembly includes an excitation means, a focusing optics provided to focus an excitation beam from the excitation means onto a sample and generate Raman scattering spectrum, a collection optics for collecting the Raman scattering spectrum, and a spectrographic detector for generating a Raman spectrum based on the Raman scattering intensity received from the collection optics. The microprocessor receives the Raman spectra signal therefrom. The laser probe assembly is situated on the adjustable stage. The driving means is coupled to the microprocessor and configured to drive the stage to move with respect to the sample. The microprocessor generates a command to the driving means for moving a position of the adjustable stage to achieve an optimal optical focus based on signal intensity of the spectra peaks measured by the spectrographic detector.
Abstract:
A transmission-reflectance swappable Raman device and a method thereof are disclosed. The excitation light is selectively directed to the sample in one direction for generating the transmission Raman signal in transmission mode or in another direction for generating the reflectance Raman signal in reflectance mode. The content of an analyte in a sample can be determined by analyzing transmission and reflectance Raman signal.
Abstract:
Methods of obtaining a multidimensional image of a sample are provided comprising (a) directing a first coherent light pulse having a first frequency ω1 and a first wave vector k1 at a first location in the sample, (b) directing a second coherent light pulse having a second frequency ω2 and a second wave vector k2 at the first location, (c) directing a third coherent light pulse having a third frequency ω3 and a third wave vector k3 at the first location and (d) detecting a coherent output signal having a fourth frequency ω4 and a fourth wave vector k4. At least two, but optionally all three, of the coherent light pulses each excite a different transition to a discrete quantum state (e.g., transitions to vibrational states or to electronic states) of a molecule or molecular functionality in the sample. Steps (a)-(d) are repeated at a sufficient number of other locations in the sample to provide the multidimensional image.
Abstract:
A raman spectrum measuring method for drug inspection is provided, comprising: measuring raman spectrum of a sample to be inspected to acquire an original raman spectrum curve of the sample; determining whether the original raman spectrum curve has a characterizing portion, and if not, measuring a mixture of the sample and an enhancing agent to acquire an enhanced raman spectrum curve of the sample; and if the original raman spectrum curve of the sample to be inspected has a characterizing portion, comparing the original raman spectrum curve of the sample with data in an original raman spectrum database of a drug to determine whether the sample contains the drug, otherwise, comparing the enhanced raman spectrum curve of the sample with data in an enhanced raman spectrum database of the drug to determine whether the sample to be inspected contains the drug.