Three-dimensional light trap for reflective particles

Patent · Tue Aug 17 04:00:00 EDT 1999

OSTI ID:678601

Neal, D R

A system is disclosed for containing either a reflective particle or a particle having an index of refraction lower than that of the surrounding media in a three-dimensional light cage. A light beam from a single source illuminates an optics system and generates a set of at least three discrete focused beams that emanate from a single exit aperture and focus on to a focal plane located close to the particle. The set of focal spots defines a ring that surrounds the particle. The set of focused beams creates a ``light cage`` and circumscribes a zone of no light within which the particle lies. The surrounding beams apply constraining forces (created by radiation pressure) to the particle, thereby containing it in a three-dimensional force field trap. A diffractive element, such as an aperture multiplexed lens, or either a Dammann grating or phase element in combination with a focusing lens, may be used to generate the beams. A zoom lens may be used to adjust the size of the light cage, permitting particles of various sizes to be captured and contained. 10 figs.

• Research Organization: Sandia Corporation
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• Assignee: Sandia Corp., Albuquerque, NM (United States)
• Patent Number(s): US 5,939,716/A/
• Application Number: PAN: 8-832,144
• OSTI ID: 678601
• Country of Publication: United States
• Language: English

Related Subjects

44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
CONTAINMENT
LIGHT SOURCES
OPTICAL SYSTEMS
PARTICLES
RADIATION PRESSURE
REFLECTIVITY
VISIBLE RADIATION