摘要:
A locally-outcoupled optical resonator has whispering gallery modes existing in a nearly circular resonator. Light is outcoupled by providing a local perturbing feature on the perimeter of the locally-outcoupled cavity resonator. The perturbing feature provides an outcoupling or loss mechanism that asymmetrically interacts with circulating whispering gallery modes, thereby making the resonator capable of uni-directional output.
摘要:
A system and method for monitoring the concentration of micron size pollutants in a gas, such as sulphate aerosols in the ambient air. The gas is drawn through a dichotomous sampler which segregates the larger aerosols from the smaller ones. The smaller sized particles of aerosols are concentrated and then flowed through an inspection chamber having a plurality of optical windows. The sample is illuminated by the light beam from a laser, and a plurality of mirrors provide a light trap to redirect the laser radiation to the sample a large number of times. The Raman scattered radiation from the particles is collected by a mirror and by a lens onto a spectrograph which provides spectrally dispersed radiation according to the molecular constituents of the sample. This radiation is detected and converted to electrical signals providing qualitative and quantitative information as to the pollutant composition and concentration.
摘要:
An aerosol deflection system having a concentration zone expelling an air stream through a first detection zone, a second detection zone, and a deflection zone. The first detection zone activates the second detection zone based upon detection of a suspect aerosol of a pre-selected size. The second detection zone activates the deflection zone when the suspect aerosol of the pre-selected size has a predetermined light-induced-fluorescence signature. The deflection zone directs a pressure pulse at the suspect aerosol having the predetermined light-induced-fluorescence signature to deflect the suspect aerosol from the air stream.
摘要:
Methods and systems for sorting particles entrained in a gaseous stream are disclosed. A representative system, among others, includes a particle scanner, a sorter, which is in pneumatic communication with the particle scanner, and a controller, which is in electrical communication with the particle scanner and sorter. The particle scanner is adapted to receive a gaseous stream and measure a characteristic of a particle entrained in the gaseous stream. The controller is adapted to classify the scanned particle according to the measured characteristic of the particle. The sorter includes an electrically controlled valve. Responsive to the particle being classified as belonging to a first category, the controller signals the valve to deflect the trajectory of the particle.A representative method, among others, for sorting particles entrained in a gaseous stream can be broadly summarized by the following steps: receiving particles in a gaseous stream; classifying a particle from the received stream of particles according to a property of the particle, wherein the particle is classified as belong to one category of a plurality of categories, and wherein the received particle has an initial trajectory; and responsive to the particle being classified as belonging to a first category of the plurality of categories, altering the trajectory of the particle.
摘要:
A particle detector has a chamber defining a pathway that a target particle follows between an entry and an exit point, a solid-state energy source such as an LED, and a re-emission sensor. The energy source imparts energy to the particle between the two points, and the sensor includes an arcuate or multi-planar lens to focus energy re-emitted by the particle. The particle is identifiable by its re-emitted energy spectrum. A scanner re-directs the beam from a single energy source to track the particle between the entry and exit points. Alternatively, the energy source is a plurality of source elements that each scan the particle at a single position. Another embodiment is a chipscale detector system wherein energy source elements are disposed on a source layer, sensor elements are disposed on a sensor layer, and one or more target particles to be detected are retained on a capture layer disposed therebetween.
摘要:
A method for fluorescence probing of particles flowing in a fluid includes defining a trigger volume in the fluid by intersecting a plurality of substantially orthogonally aimed trigger laser beams, each of a different wavelength, detecting light scattered from the vicinity of the trigger volume by a plurality of particle detectors each sensitive to a wavelength corresponding to the wavelength of a trigger laser beam, probing the particles with a pulsed laser triggered by the particle detectors, collecting fluorescence emitted from the particle in a detection volume and focusing it in a detection region, detecting the fluorescence focused in the detection region. The invention also includes devices for carrying out the foregoing method.