Abstract:
A method of Raman detection for a portable, integrated spectrometer instrument includes directing Raman scattered photons by a sample to an avalanche photodiode (APD), the APD configured to generate an output signal responsive to the intensity of the Raman scattered photons incident thereon. The output signal of the APD is amplified and passed through a discriminator so as to reject at least one or more of amplifier noise and dark noise. A number of discrete output pulses within a set operational range of the discriminator is counted so as to determine a number of photons detected by the APD.
Abstract:
An optical spectroscopy tool is provided. In one embodiment a highly efficient means by which moderate resolution spectroscopy may be performed in the vacuum ultraviolet (VUV) is described. In one embodiment the techniques can be used as a high throughput spectrometer to spatially disperse wavelengths in and around the VUV in such a manner as to generate a substantially flat field focal plane, suitable for use in combination with an array detector. Some embodiments utilize prism based spectrometers. Some embodiments utilize detector elements that may be movable and/or located within the spectrometer. In some embodiments, collimated light may be provided as an input to the spectrometer.
Abstract:
A technique is provided for generating and subsequently monitoring the controlled environment(s) within an optical metrology instrument in such a manner as to minimize absorbing species within the light path of the metrology instrument and to minimize the build-up of contaminants on the surfaces of optical elements that may result in performance degradation. Both evacuation and backfill techniques may be utilized together along with a monitoring technique to determine if the environmental is suitable for measurements or if the environment should be regenerated. The optical metrology instrument may be an instrument which operates at wavelengths that include vacuum ultra-violet (VUV) wavelengths.
Abstract:
Weak signals scattered from analytes at multiple wavelengths can be summed to illuminate either a single detector or a multiplicity of detectors, offering the possibility of concentrating the spectral energy on a smaller total detector area. In addition, a method is disclosed whereby a calibration of the resulting signal for a given analyte can be obtained by means of measuring the quantity of water in the sample volume and by means of measuring the salinity of the fluid in the sample volume.
Abstract:
A cartridge and cartridge system for use in an apparatus for analyzing a sample is provided. The cartridge has one or more light sources and/or optical systems and other components that are specific for a certain type of application such as fluorescence, absorbance, or luminescence. The light source, optical systems, and other components for a specific application are housed in a single cartridge. The system has a plurality of cartridges for different applications for a multimode instrument. The cartridges are removably engaged with the apparatus in a “plug-in” format such that one cartridge may be removed from the apparatus and another cartridge may be easily installed.
Abstract:
A downhole fluid analysis system comprises an input light signal that is directed through a fluid sample housed in a sample cell. The input light signal may originate from a plurality of light sources. A light signal output from the sample cell is then routed to two or more spectrometers for measurement of the represented wavelengths in the output light signal. The output of the spectrometers is then compared to known values for hydrocarbons typically encountered downhole. This provides insight into the composition of the sample fluid. Additionally, the input light can be routed directly to the two or more spectrometers to be used in calibration of the system in the high temperature and noise environment downhole.
Abstract:
Systems and methods for providing multi-spectral image capability using an integrated multi-band focal plane array that, in one example, may be employed to simultaneously image in the visible spectrum and infrared spectrum using an integrated dual-band focal plane array, e.g., by including visible imaging circuitry within read out integrated circuitry (ROIC) used to readout infrared detector elements within the same pixel element/s.
Abstract:
An endoscope having an optical guide that is optically coupled to a first broadband light source and a second laser light source that emits light at a wavelength in a range of 350 nm to 420 nm. The endoscope has an image sensor at a distal end and collects a reflectance image including red, green and blue components with the image sensor in response to illumination by said broadband light source. The image sensor also collects an autofluorescence image having a blue component, a green component and a red component. A processor processes the fluorescence image by determining a ratio of the fluorescence image and the reflectance image to provide a processed fluorescence image.
Abstract:
An apparatus for performing real-time analysis of a subterranean formation fluid includes a light source configured to transmit at least a sample signal through a sample of the subterranean formation fluid and a reference signal, at least one photodetector configured to continuously detect the sample and reference signals, and an electronics assembly configured to compensate for drift in the detected sample signal in real-time based on the value of the detected reference signal.
Abstract:
A spectroscopy system is provided which is optimized for operation in the VUV region and capable of performing well in the DUV-NIR region. Additionally, the system incorporates an optical module which presents selectable sources and detectors optimized for use in the VUV and DUV-NIR. As well, the optical module provides common delivery and collection optics to enable measurements in both spectral regions to be collected using similar spot properties. The module also provides a means of quickly referencing measured data so as to ensure that highly repeatable results are achieved. The module further provides a controlled environment between the VUV source, sample chamber and VUV detector which acts to limit in a repeatable manner the absorption of VUV photons. The use of broad band data sets which encompass VUV wavelengths, in addition to the DUV-NIR wavelengths enables a greater variety of materials to be meaningfully characterized. Array based detection instrumentation may be exploited to permit the simultaneous collection of larger wavelength regions.