Abstract: Localized measurement of turbulent airflows is provided using enhanced techniques of digital holography with computed tomography. In an implementation, an optical beam is diffracted to produce an array of signal beams which propagate at different angles through a test volume that includes a test article. A reference beam is optically interfered with the array of signal beams after propagating through the test volume, producing a corresponding array of holograms simultaneously detected by a single digital holographic sensor. Digitized versions of the holograms are processed to produce a signal field for each test beam. Computed tomography is then applied to the signal fields to determine path-resolved turbulence measurements.

Abstract: Method and apparatus are provided for NLO switching by first providing a phase-matched SHG grating which outputs a reinforced SHG beam only when two input beams of frequency (.omega.) are present in two modes of such wg. The so encoded NLO switch is operated by directing at least two input pulsed laser beams of frequency (.omega.) into the two modes of the wg to generate a reinforced pulsed output SHG beam and output same from the wg in an NLO switching process. The two input beams desirably have a separate pulse train and the spatial and temporal overlap of the input beams are adjusted such that at least some of the pulses of each pulse train sufficiently overlap to generate and output reinforced SHG pulse signals and thus output an on-off data signal. A detector then reads and processes the output signals. Such NLO switch will allow integrated circuitry to operate at faster rates and to allow, eg.