Eva M. Strzelecki

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.

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.

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.

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.

Self-Aligned Optical Holographic Clock Distribution Networks

Several novel optical holographic VLSI clock distribution networks are presented. Cascaded holographic structures used for the realization of these networks have the following unique characteristics: (i) High-density uniform fanouts; (ii) Reduced clock skew problems; and (iii) self-aligned holograms. These clock distribution networks can be either realized in a free-space or single-mode planar waveguide geometry.

Wavelength multiplexer using dispersion-compensated pairs of diffraction gratings in a guided-wave structure

This wavelength division multiplexer (WDM) architecture employs a number of dispersion compensated gratings in a guided-wave structure to perform the major functions of wavelength multiplexing or demultiplexing. The characteristic performance analysis, including wavelength dispersion, effect of beam divergence, and power budget are presented.

Fiber optic compact crossbar switch using holographic couplers in planar geometry

A compact crossbar switch array based on matrix-vector multiplication is proposed. The crossbar is composed of beam splitting and beam combining holographic structures in substrate mode waveguides and a liquid crystal spatial light modulator. A design of a 4 X 4 crossbar is presented.

Integrated compact matrix-vector multipliers for optical interconnect applications

interconnects, where energy constraints are not as stringent as in communications, large scale arrays can be achieved at theexpense of fan-out loss. In addition, broadcast capability is achieved. Such crossbars, based on the principle of matrix-vectormultiplication, require a large scale spatial light modulator (SLM) and elements for collimating and collecting the input andoutput light. This has been done with lenses which are bulky and with fiber couplers2 which require cumbersome alignment.

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.

Holoplanar optical interconnects

A novel optical interconnect technology is presented. It combines single mode waveguides with multiplexed volume waveguide holograms to provide a highly parallel, very wide bandwidth system for VLSI, computer board or backplane computer interconects. Interconnect density and system performance are analyzed. Experimental results of a 1-to-20 waveguide interconnection are presented.