Biomedical subjects

Timothy D Wilkinson

Publications and source records attributed to Timothy D Wilkinson.

4 recordsLinked to original sources

PubMed2006

Resolution in optically addressed spatial light modulators based on dye-doped liquid crystals.

Dye-doped nematic liquid crystals (LCs) are studied as materials for single-layer optically addressed spatial light modulators. The dopant is 2,5-azo-substituted anthraquinone (ASAQ) dye. The resolution in the ASAQ-doped LC systems does not depend on the device thickness (in the 5-125 microm range). The efficiency increases with the increase of the thickness and begins to saturate in devices thicker than 40 microm. The limiting resolution in the thick devices is 400 line pairs per millimeter. The limitations of performance (efficiency and resolution) in the studied systems are discussed.

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PubMed2006

Aberration correction in an adaptive free-space optical interconnect with an error diffusion algorithm.

Aberration correction within a free-space optical interconnect based on a spatial light modulator for beam steering and holographic wavefront correction is presented. The wavefront sensing technique is based on an extension of a modal wavefront sensor described by Neil et al. [J. Opt. Soc. Am. A 17, 1098 (2000)], which uses a diffractive element. In this analysis such a wavefront sensor is adapted with an error diffusion algorithm that yields a low reconstruction error and fast reconfigurability. Improvement of the beam propagation quality (Strehl ratio) for different channels across the input plane is achieved. However, due to the space invariancy of the system, a trade-off among the beam propagation quality for channels is obtained. Experimental results are presented and discussed.

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PubMed2006

Cross-talk analysis in a telecentric adaptive free-space optical relay based on a spatial light modulator.

We present an analysis of the performance limit of an adaptive multichannel free-space optical interconnect based on a spatial light modulator (SLM). The SLM function is to provide an active alignment of the signal beam in the detector plane. A thorough cross-talk analysis based on the diffractive properties of an ideal SLM in an isoplanatic optical system is shown. We analyze the performance in terms of the bit-error rate (BER) due to cross talk between different channels in the optical interconnect for different alignment states and for different phase-modulation schemes.

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PubMed2004

Design and analysis of an adaptive board-to-board dynamic holographic interconnect.

We describe the design and analysis of an adaptive free-space optical interconnect between two circuit boards in a standard electronic backplane. An array of vertical-cavity surface-emitting lasers is used as the transmitter, and this communicates with a detector array on the receiver circuit board. Routing is achieved with a holographic crossbar that has a ferroelectric liquid-crystal spatial light modulator to display binary phase computer-generated holograms. A detailed analysis of a 48-channel interconnect designed to operate at 1 (Gbytes/s)/channel indicates that such a switch will operate successfully given typical components and card misalignments.

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