Multiplexed holographic Fabry-Perot étalons.

We discuss a multiplexed holographic Fabry-Perot étalon that includes a multiplexed hologram in a novel holographic Fabry-Perot étalon. Two unique advantages can be achieved by using the multiplexed holographic Fabry-Perot étalon: coherently coupled fabrication of holographic Fabry-Perot mirrors significantly reduces the need to have the nearly flat surfaces typically required in conventional Fabry-Perot etalons, and the angular-wavelength multiplexing capability of a multiplexed hologram can be added to the tunable narrow-band filtering capability of Fabry-Perot étalons. Several types of multiplexed holographic Fabry-Perot étalon are experimentally demonstrated.

Highly parallel single-mode multiplanar holographic interconnects.

We present theoretical and experimental results of a novel highly parallel multiplanar holographic interconnect design. It combines single-mode integrated optics with highly efficient volume holography and holographic waveguide couplers. A multiple-plane optical bus was fabricated. The interconnect density and power budget of the system are presented. This new type of very-large-scale integrated interconnect can provide performance benefits for local area networks and highly parallel supercomputing systems.

Optical polynominal processing based on a cascaded holographic structure.

An optical polynomial processor is investigated to evaluate a general class of nonlinear functions. The polynomial processor is based on a cascaded holographic array that is reconstructed by an off-Bragg laser beam. By means of cascaded off-Bragg reconstructions, a series of polynomial terms can be obtained in parallel at light-transmitted speed.

Optically addressed variable-efficiency waveguide grating for switching arrays.

An optically addressed waveguide grating switch is described and demonstrated. Its structure includes a planar slab waveguide with a surface relief grating and an active-material cladding layer. Photoinduced birefringence due to a polarized argon laser beam causes modulation of the refractive index of the cladding in the grating region and modulation of diffraction efficiency of the waveguide grating.

Optical multiplanar VLSI interconnects based on multiplexed waveguide holograms.

Optical interconnects for very large scale integration systems based on planar waveguide holograms are analyzed. The combination of low loss waveguides and multiplexed waveguide holograms allows the construction of various compact planar architectures with high interconnect density and low insertion loss. The long interaction lengths possible in planar structures result in high angular and wavelength selectivity. Holographic grating couplers and multiplexed planar holograms for 1-to-3 interconnects and 1-to-3 multiple wavelength interconnects were fabricated.

A survey of aflatoxin levels in peanut meal imported into Poland for animal feedingstuffs.

Peanut meals (366 samples) imported into Poland from Brazil and India during 1984-86 for use in animal feedingstuffs were analysed for aflatoxins B1 and B2. Average levels of contamination were 71 micrograms per kg for aflatoxin B1 and 16 micrograms per kg for aflatoxin B2 with total concentrations ranging from 2 to 750 micrograms per kg.

Levels of aflatoxin B1, bacteria and fungi in feed and food in 1971 - 1987.

Totally 39% out of 8371 feed and their component samples were contaminated by aflatoxin B1. Mean contamination was 36µg/kg with maximum yield 10100 µg/kg. Contamination of samples by total count of organisms, mean contamination and maximum yield, respectively was: 1) bacteria 99%, 2.2×10(6), 2.4×10(8); 2) proteolytic bacteria 94%, 1.2×10(5), 3.0×10(6);3) moulds 98%, 1.3×10(5), 9.0×10(6); 4) yeasts 44 %, 3.3×10(4), 3.6×10(6). The samples were contaminated in 92 % byAspergillus spp, in 71% byAspergillus flavus, in 83% byPenicillium spp, and in 20% byFusarium spp with mean contamination 8.3×104, 1.1×10(3), 4.2×10(4), 5.0×10(3) , and maximum yield 6.8×10(6), 1.0×10(5), 5.0×10(6), 1.5×10(6), respectively. Totally 8.5% of strains were aflatoxinogenic and 4.4% of the strains were isolated from feed and 21 % of the strains from grain/nut.

Country cured ham as a possible source of aflatoxin.

Of 10 fungi isolated from a heavily molded country cured ham, 4 were identified as toxigenic strains of Aspergillus flavus.