Abstract:
There is disclosed a method for assessing a cancer status of biological tissue having the steps of: obtaining a Raman spectrum indicating a Raman spectroscopy response of the biological tissue, the Raman spectrum captured using a fiber-optic probe of a fiber-optic Raman spectroscopy system; inputting the Raman spectrum into a boosted tree classification algorithm of a computer program, and using the boosted tree classification algorithm for comparing, in real-time, the captured Raman spectrum to reference data and assessing the cancer status of the biological tissue based on said comparison, the reference data being previously determined based on a set of reference Raman spectra indicating Raman spectroscopy responses of reference biological tissues wherein each of the reference biological tissues is associated with a known cancer status; and generating a real-time output indicating the assessed cancer status of the biological tissue.
Abstract:
A two-core optical fiber is provided for use in Brillouin distributed fiber sensor applications and systems. The two-core fiber includes a first and second core. Each core is configured to exhibit a Brillouin frequency shift greater than 30 Mhz relative to the other core. Further, each core possesses temperature and strain coefficients that differ from the other core. The cores can be configured to produce Brillouin frequency shift levels of at least 30 Mhz relative to one another. These differences in shift levels may be effected by adjustment of the material compositions, doping concentrations and/or refractive index profiles of each of the cores. These optical fibers may also be used in BOTDR- and BOTDA based sensor systems and arrangements.
Abstract:
L'invention concerne un dispositif (100) de détection et/ou de dosage d'hydrogène destiné à la surveillance d'une installation (1). Ledit dispositif (100) comporte une première fibre optique de mesure (10) destinée à équiper l'installation (1), et un système optique (20) relié optiquement à la première fibre optique de mesure (10) et adapté pour mesurer la variation d'au moins un paramètre de la première fibre optique de mesure (10). Le système optique (20) est adapté effectuer la mesure du paramètre le long de la première fibre optique (10) selon le principe de la mesure du type Brillouin. L'invention concerne également un procédé de mise en œuvre d'un tel dispositif (100)
Abstract:
L'invention concerne un capteur à fibre permettant la propagation de la lumière infrarouge à au moins une longueur d'onde de 0.8 à 25 micromètres, la fibre comportant successivement sur sa longueur un premier tronçon (23) de guidage de l'onde infrarouge, un deuxième tronçon (25) de détection destiné à venir en contact avec un milieu extérieur pour détecter des signatures infrarouges perturbant la propagation des ondes évanescentes se propageant le long de la fibre (2), et un troisième tronçon (27) de guidage de l'onde infrarouge. L'invention est caractérisée en ce que dans le deuxième tronçon (25) de fibre ayant la fonction de détection la fibre (2) est constituée d'une partie courbe dont le rayon de courbure est localement inférieur à 2.3 millimètres.
Abstract:
An apparatus for estimating a parameter at distributed locations, the apparatus including: an optical fiber having: a first series of fiber Bragg gratings (FBGs) and configured to measure the parameter at a portion of the distributed locations; a second series of FBGs and configured to measure the parameter at another portion of the distributed locations; and an optical interrogator configured to illuminate the optical fiber and to receive light signals resulting from the illumination, the light signals including first light signals from the first series of FBGs within a first range of wavelengths, second light signals from the second series of FBGs within a second range of wavelengths, and other light signals within a third range of wavelengths, the ranges of wavelengths being distinct from each other; wherein the first light signals and the second light signals are used to estimate the parameter at the distributed locations.
Abstract:
The present invention relates to a method and system of array imaging that extends or maximizes the longevity of the sensor array by minimizing the effects of photobleaching. The imaging system has a light source, a variable exposure aperture, and a variable filter system. The system extends the longevity of sensors by (1) using the variable exposure aperture to selectively expose sections of the sensor array containing representative numbers of each type of sensor, and/or (2) using the variable filter system to control the intensity of the excitation light, providing only the intensity required to induce the appropriate excitation and increasing that intensity over time as necessary to counteract the effects of photobleaching.
Abstract:
A fiber-optic sensor can have a Michelson sensor portion and a Mach-Zehnder sensor portion. A first splitter-coupler can be configured to split incoming light between a first fiber portion and a second fiber portion. A first polarization-phase conjugation device can be configured to conjugate a polarization phase of incident light corresponding to the first fiber portion, and a second polarization-phase conjugation device can be configured to conjugate a polarization phase of incident light corresponding to the second fiber portion. Each of the first and second polarization-phase conjugation devices can be configured to reflect light toward a detector and through the respective first and second fiber portions. A coupler can be configured to join light in the first fiber portion with light in the second fiber portion, and a third fiber portion can be configured to receive light from the coupler and to illuminate a second detector.
Abstract:
A device and method for tracking a spectral response. The device and method including inputting light to a waveguide medium having a plurality of perturbation sensors disposed in a spaced relationship in the waveguide medium; receiving a plurality of signals reflected from the plurality of perturbation sensors; retrieving from the received signals, data representing a plurality of signal values, each signal value comprising at least a magnitude value and a wavelength value; identifying within the plurality of signal values, at least a first signal value and a second signal value, being in an overlap state; estimating, for at least some of the plurality of perturbation sensors, an expected signal value; associating each expected signal value with a respective signal value from the plurality of signal values; updating each expected signal value with the associated signal value.