N-slit laser interferometer developed
ROCHESTER, N.Y. – Scientists have developed an N-slit laser
interferometer that is suitable for secure terrestrial free-space optical communications
over propagation distances and clear-air turbulence detection.
The device was created by physicists from Interferometric Optics
and the US Army Space and Missile Defense Command. The findings were reported in
the Feb. 3, 2011, issue of Journal of Optics (doi: 10.1088/2040-8978/13/3/035710).
Previously, N-slit interferometers were used for industrial metrology
applications, including microdensitometry, microscopy and optical modulation measurement
of thin-film gratings generated from a variety of manufacturing processes. Advantages
of this type of interferometer include a simple architecture and the use of low-
to medium-power single-transverse-mode narrow-linewidth lasers.
The scientists proved experimentally that the device is a viable
interferometric tool over long free-space propagation paths under fair atmospheric
conditions. In the lab, they demonstrated that very subtle attempts to intercept
the interferometric characters, using microscopic natural fibers, could be detected
by observing the diffraction patterns superimposed over the interferometric signal.
The US Army High Energy Laser Laboratory project was funded through
a subcontract to BAE Systems.
- An instrument that employs the interference of lightwaves to measure the accuracy of optical surfaces; it can measure a length in terms of the length of a wave of light by using interference phenomena based on the wave characteristics of light. Interferometers are used extensively for testing optical elements during manufacture. Typical designs include the Michelson, Twyman-Green and Fizeau interferometers.
The basic interferometer components are a light source, a beamsplitter, a reference...
- optical communications
- The transmission and reception of information by optical devices and sensors.
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