Arthur E. T. Chiou

Optical interconnection using photorefractive dynamic holograms

On decrit une nouvelle methode pour definir une nouvelle configuration des interconnexions optiques en utilisant des hologrammes dynamiques dans des cristaux photorefractifs

Parallel image subtraction using a phase-conjugate Michelson interferometer.

A phase-conjugate Michelson interferometer using an internally self-pumped barium titanate crystal as reflectors has been constructed to perform parallel image subtraction, intensity inversion, and exclusive or logic operation. These operations are independent of the optical path differences and phase aberration.

Beam cleanup using photorefractive two-wave mixing

Photorefractive two-wave mixing exhibits energy transfer without phase cross talk. Such a phenomenon can be used to clean up wave-front aberrations of laser beams. We report the cleanup of spatial and temporal phase aberration using photorefractive two-wave mixing in a strontium barium niobate crystal.

Photorefractive Nonlinear Optics And Optical Computing

This paper describes various nonlinear optical phenomena in photorefractive media and selected applications in optical computing. These phenomena include optical phase conjugation, two- and four-wave mixing, and real-time holography. The applications include image amplification and subtraction, logic and matrix operations, and optical interconnection.

Optical matrix–vector multiplication through four-wave mixing in photorefractive media

We propose and describe a new method of optical matrix-vector multiplication by using four-wave mixing in photorefractive media. Using a BaTiO(3) crystal, we have demonstrated such a parallel multiplication. The results are presented and discussed.

Laser-beam cleanup using photorefractive two-wave mixing and optical phase conjugation.

Using photorefractive two-wave mixing in a strontium barium niobate (Sr(x)Ba(1-x)Nb(2)O(6)) crystal in conjunction with a self-pumped barium titanate (BaTiO(3)) phase conjugator, we have demonstrated the cleanup of a phase-distorted laser beam. A clean seed beam is amplified by the phase-aberrated pump beam through the photorefractive two-wave mixing process. The optical phase conjugation is used to eliminate the phase aberration introduced by the photorefractive gain medium.

Energy efficiency of optical interconnections using photorefractive holograms

We propose and demonstrate the use of a Fourier transform to achieve maximum energy efficiency in a photorefractive optical interconnection. The results of experimental investigations on reconfigurable optical interconnections using photorefractive holograms in a barium titanate crystal are presented and discussed. High energy efficiency is achieved by matched amplification at the Fourier plane.

Image amplification by two-wave mixing in photorefractive crystals

Coherent amplification of images by two-wave mixing in photorefractive crystals is examined with attention given to processing in the Fourier domain. It is shown that the gain that is experienced as the probe image traverses the crystal is approximately uniform across the image. The gain can be expressed as a function of the average probe to pump intensity ratio. Experimental verification is given to support the theory.

Anisotropic cross talk in an optical interconnection by using a self-pumped phase-conjugate mirror at the Fourier plane

Experimental evidence that the cross talk that is due to Bragg degeneracy of the multiplexed volume holograms in a self-pumped phase conjugator at the Fourier plane is reduced along the horizontal direction but not the vertical direction is described. A qualitative explanation is given, and its implication on other anisotropic properties of Fourier-transformed volume holograms under broad conditions is discussed.

2 x 8 photorefractive reconfigurable interconnect with laser diodes

We report the demonstration and characterization of a 2 x 8 optical reconfigurable interconnect with laser diodes at 780 nm and a ferroelectric liquid crystal spatial light modulator in conjunction with a photorefractive barium titanate crystal. The photorefractive holograms improve the energy efficiency by 6 to 10 dB over the conventional approach.