No abstract

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.

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.

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.

The benefits of using optics for massively parallel interconnects between electronic processors are well known. Additional flexibility can be achieved if optical switches are used to create reconfigurable optical interconnects. The enhanced efficiency of holograms placed in optical resonators has been proposed for the use in passive interconnects [1,2], for active devices [3], and for dense wavelength division multiplexing [4]. If a diffraction grating is placed inside a resonator, such as a Fabry-Perot resonator, its interaction length, and consequently its efficiency, can be significantly increased because of multiple paths of the optical beam inside a cavity in resonance. As a result, a combination of the characteristics of diffraction gratings and optical resonators is achieved: the direction of light can be changed and the efficiency of the diffracted beam exhibits peaks similar to that of a Fabry-Perot resonator. If the cavity can be tuned, the features of resonated holograms can be utilized for switching of light beams in optical interconnects. However, optical resonators pose great fabrication difficulties primarily due to stringent alignment requirements. We propose and demonstrate holographically recorded tunable Fabry-Perot resonators for the use in this optical interconnect configuration. Simultaneous recording of two high efficiency reflection gratings, which replace regular mirrors, removes the alignment problems. In addition, the use of volume holographic materials with refractive index modulation allows recording of multiplexed gratings to create multiple mirror resonators in a compact form which results in a much higher effective efficiency of the resonated grating.