Abstract:
Raman spectroscopy systems include an analyte, a radiation source configured to emit incident radiation having a wavelength, and a detector that is capable of detecting only radiation having wavelengths within a detectable range that includes at least one wavelength corresponding to hyper Raman scattered radiation scattered by the analyte. The wavelength of the incident radiation is outside the detectable range. In particular systems, all wavelengths of radiation that are scattered in the direction of the detector impinge on the detector. Raman spectroscopy methods include providing an analyte and irradiating the analyte with incident radiation having a wavelength, providing a detector capable of detecting only wavelengths of radiation within a detectable range that does not include the wavelength of the incident radiation, and detecting Raman scattered radiation scattered by the analyte. A continuous path free of radiation filters may be provided between the analyte and the detector.
Abstract:
The disclosed methods and apparatus concern Raman spectroscopy using metal coated nanocrystalline porous silicon substrates. Porous silicon substrates may be formed by anodic etching in dilute hydrofluoric acid. A thin coating of a Raman active metal, such as gold or silver, may be coated onto the porous silicon by cathodic electromigration or any known technique. In certain alternatives, the metal coated porous silicon substrate comprises a plasma-oxidized, dip and decomposed porous silicon substrate. The metal-coated substrate provides an extensive, metal rich environment for SERS, SERRS, hyper-Raman and/or CARS Raman spectroscopy. In certain alternatives, metal nanoparticles may be added to the metal-coated substrate to further enhance the Raman signals. Raman spectroscopy may be used to detect, identify and/or quantify a wide variety of analytes, using the disclosed methods and apparatus. In some disclosed methods, Raman spectroscopy may be used to detect nucleotides, purines or pyrimidines at the single molecule level.
Abstract:
An interferometer includes a resonant cavity having a movable mirror and at least one fiber optic component acting as a fixed mirror. A surface of the fiber optic component is coated with a reflective film. An actuator is coupled to the movable mirror, such that when a scattered optical beam is coupled to the cavity, interference occurs between the surface of the fiber optic component coated with reflective film and a surface of the movable mirror facing the surface of the fiber optic component coated with reflective film. The reflective film on the surface of the fiber optic component causes closely spaced spectral lines within the scattered optical beam to be suitably resolved.
Abstract:
Devices, systems, and methods for enhancing Raman spectroscopy and hyper-Raman are disclosed. A molecular analysis device for performing Raman spectroscopy comprises a substrate and a laser source disposed on the substrate. The laser source may be configured for emanating a laser radiation, which may irradiate an analyte disposed on a Raman enhancement structure. The Raman enhancement structure may be disposed on the substrate or apart from the substrate. The molecular analysis device also include a radiation receiver disposed on the substrate and configured for receiving a Raman scattered radiation, which may be generated by the irradiation of the analyte and Raman enhancement structure.
Abstract:
A gas leakage monitoring method and system capable of ensuring safety of a gas utilization facility by visualizing invisible-to-naked-eye leakage gas and/or flame of leakage gas into the form of an image. The gas leakage monitoring method comprises the steps of collecting a detected light of a particular wavelength, which is caused by leakage gas and/or a flame of the leakage gas, in a space to be monitored, converting the detected light into an electronic image, amplifying and then converting the electronic image into an optical image again, and imaging the spatial intensity distribution of the particular wavelength light. The gas leakage monitoring system comprises first means for collecting a detected light of a particular wavelength, which is caused by leakage gas and/or a flame of the leakage gas, in a space to be monitored, second means for converting the detected light into an electronic image, and amplifying and then converting the electronic image into an optical image again, and third means for imaging the spatial intensity distribution of the particular wavelength light.
Abstract:
A method to fabricate an optical scattering probe and the method includes the steps of a) depositing an conductive layer on a substrate followed by depositing a noble metal layer on top of the conductive layer and then an aluminum layer on top the noble metal layer; b) anodizing the aluminum layer to form a porous aluminum oxide layer having a plurality of pores; and c) etching the plurality of pores through the aluminum oxide layer and the noble metal layer for forming a nano-hole array. In a preferred embodiment, the step of etching the plurality of pores through the aluminum oxide layer and the noble metal layer further comprising a step of widening the pores followed by removing the aluminum oxide layer for forming a plurality of noble metal column on top of the conductive layer.
Abstract:
An improved optical sensor and methods for measuring the presence of various materials or constituents in a fluid sample uses one or more reactive materials in a fluid environment. The reactive materials have optical properties that change in the presence of one or more target materials that may be present in the environment. One or more optical emitters generate light that is directed to the reactive material(s), and one or more optical detectors receive light from the reactive material(s), and the presence or absence of the target material is determined based on the light received at the optical detector(s). The reactive material(s), emitter(s), and detector(s) are selected based on the desired target material to be sensed.
Abstract:
The invention concerns a Raman spectrometry apparatus containing a source of excitation (14), optical means (16) of excitation directing a beam of excitation (15) derived from that source on the sample (17), means (18) for collecting the energy diffused by the sample (17) containing an inlet diffusion slot (19), a spectral dispersion system (20), means for selecting the Raman energy (23), a detector (22), optical detection means (21) directing the Raman energy thus collected and selected to the detector (22). According to the invention, the optical means (16) of excitation cause the beam of excitation (15) to be dispersed by the dispersion system (20), said optical means (16) of excitation containing an inlet slot (24) and an outlet slot of excitation constituted by the inlet diffusion slot (19) and selecting the wavelength of excitation.
Abstract:
Compositions and methods utilizing Raman Spectroscopy to detect and determine, directly or indirectly, the concentration of water treatment polymers in water or methods for measuring or quantifying the amount of water treatment polymer in a sample, such as an industrial, commercial, or municipal water sample, are provided. The compositions contain water treatment polymers that have been modified to include one or more Raman-active functional groups. The methods utilize Raman spectroscopy to detect the presence or amount of water treatment polymer either directly or indirectly. The method provides the ability to detect or measure the amount of active water treatment polymer remaining in the sample.
Abstract:
The invention provides a system and method for automatic real-time monitoring for the presence of a pathogen in water using coherent anti-stokes Raman scattering (CARS) microscopy. Water sample trapped in a trapping medium is provided to a CARS imager. CARS images are provided to a processor for automatic analyzing for the presence of image artifacts having pre-determined features characteristic to the pathogen. If a match is found, a CARS spectrum is taken and compared to a stored library of reference pathogen-specific spectra for pathogen identification. The system enables automatic pathogen detection in flowing water in real time.