US Government As Represented by the Secretary of the Army

Yale University

Yongle Pan

Richard Kounai Chang

Steven Clyde Hill

Aimable Kalume

Gorden W Videen

Kristan Peter Gurton

Jean-Pierre Wolf

Brandon Redding

Jessica A Arnold

Veronique Boutou

Systems and methods for trapping and holding airborne particles using an orienting hollow beam are disclosed. In the various embodiments, an optical trap comprises: a light source for generating a beam of light; optics and/or mechanics for forming and shaping the beam of light into an orienting hollow beam having unequal axisymmetry with a substantially hollow ring geometry cross-section and no angular momentum; an optical focusing element for focusing the orienting hollow beam; and a trapping region where an airborne particle can be present to be trapped and held at or near a focal point of the focused optical focusing element. In this arrangement, the particle is trapped at or near the focal point of the focused orienting hollow beam. In this arrangement, the particle is trapped at or near the focal point of the focused orienting hollow beam. The orienting hollow beam may be made rotatable in some embodiments.

Optical trap using a focused hollow beam of unequal axisymmetry and no angular momentum for trapping and rotating airborne particles

Embodiments of the present invention are directed to systems and methods for trapping and holding airborne particles, for further measurement and characterization. In the various embodiments, an optical trap is provided which generates and uses dual hollow conical beams to trap and hold absorbing and non-absorbing, spherical and irregularly shaped, liquid and solid airborne particles. The optical trap may include: a light source for generating a beam of light; optics for shaping and forming a hollow conical beam having a ring geometry from the beam of light; a trapping region where a particle can be present to be trapped; a first parabolic reflector configured to focus an inner portion of the hollow conical beam to a first focal point in the trapping region; and a second parabolic reflector configured to focus an outer portion of the hollow conical beam to a second focal point in the trapping region.

Optical trapping of airborne particles using dual counter-propagating hollow conical beams

A system for trapping particles in a gas comprising a chamber; an intake for intake of a gas containing at least one particle to be trapped and released, and an outlet for exit of the gas out of the chamber containing at least one particle; a first passage operatively connected to the intake operating to create a flow of a gas containing at least one particle into the chamber, a second passage operatively connected to the outlet for flow of the gas; a third passage operatively connected to a gaseous flow for creating a flow of fluid in a direction substantially opposite to the transfer of gas from the first passage so as to counteract the flow of gas from the first passage; an image sensor for recording an image; and a laser for generating a light beam for forming a photophoretic trap between the first and third passages.

System for sampling and/or analysis of particles in a gaseous environment

Embodiments of the present invention are directed to systems and methods for trapping and holding airborne particles. In the various embodiments, an optical trap is provided which uses a focused hollow-beam for trapping and holding both absorbing and non-absorbing airborne particles. The optical trap comprises: a trapping region where a particle can be present to be trapped; a light source for generating a coherent beam of light; optics for forming a hollow beam having a ring geometry from the coherent beam of light; and a focusing element for focusing the hollow beam to a point in the trapping region. In this arrangement, the particle is trapped at or near the focal point of the focused hollow beam.

Optical trap using a focused hollow-beam for trapping and holding both absorbing and non-absorbing airborne particles

Embodiments of the present invention are directed to systems and methods for continuously sampling particles from air. In one embodiment, a system for continuously sampling particles from air may include: an airflow system configured to continuously draw air including airborne particles into the system; a photophoretic trap that uses photophoretic forces of a laser beam to trap one or more of the airborne particles from the drawn air; a measurement device configured to measure one or more properties of the trapped one or more airborne particles; and a controller configured to repeatedly trap, measure and release one or more airborne particles.

Systems and methods for individually trapping particles from air and measuring the optical spectra or other properties of individual trapped particles

A method and system for detecting composition of a physical space comprising: a laser beam source; an acoustic sensor; a beam focusing mechanism for focusing the laser beam at predetermined points in the physical space to generate a thermal inhomogeneity which results in the propagation of a pressure wave that propagates outward from the predetermined excitation point at a propagation velocity approximating the speed of sound for the particular composition of the media; at least one processor for controlling the timing for the laser beam focusing to generate thermal inhomogeneities; whereby the laser focal point is moved sequentially along the light-of-sight at various excitation points by the beam focusing mechanism approximately at the phase front velocity to define a series of predetermined excitation points and pressure wave propagations such that the series of pressure wave propagations combine to produce a coherent pressure wave detectable by the acoustic sensor.

Remote sensing using coherent sonic wave photoacoustic detection and methods

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.

Method and system for sorting particles sampled from air

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.

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Cheshire, CT, United States of America

Yongle Pan