Design and implementation of a modulator-based free-space optical backplane for multiprocessor applications

Abstract

Design and implementation of a free-space optical backplane for multiprocessor applications is presented. The system is designed to interconnect four multiprocessor nodes that communicate by using multiplexed 32-bit packets. Each multiprocessor node is electrically connected to an optoelectronic VLSI chip which implements the hyperplane interconnection architecture. The chips each contain 256 optical transmitters (implemented as dual-rail multiple quantum-well modulators) and 256 optical receivers. A rigid free-space microoptical interconnection system that interconnects the transceiver chips in a 512-channel unidirectional ring is implemented. Full design, implementation, and operational details are provided.

Surface-normal electro-optic-polymer modulator with silicon subwavelength grating

“…Having inherent compatibility with dense 2-D array integration, they have found wide range of potential applications, including high-capacity optical interconnects [1,2], freespace optical communications [3], dynamic beam forming and adaptive optics [4,5]. Surface-normal modulators based on liquid crystals and micro-electromechanical systems (MEMS) are relatively mature; but their operating speed is typically in a range from kHz up to MHz [4,5,6].…”

“…Surface-normal modulators based on liquid crystals and micro-electromechanical systems (MEMS) are relatively mature; but their operating speed is typically in a range from kHz up to MHz [4,5,6]. On the other hand, high-speed surface-normal intensity modulators with bandwidth beyond GHz range have been demonstrated by using multiple-quantum-well (MQW) semiconductor materials [1,2,3]. These devices, however, require complicated epitaxial structures and are inherently absorptive, which makes them unsuitable for some applications.…”

Integration strategies for micro-optical systems

“…Here we use 'micro-optical' to include any system in which light propagates as an unguided wave in at least part of the system, and where the optical beams have dimensions of microns to millimeters. Computer interconnects typically require parallel point-to-point links, and examples of such systems include intra-chip links [1], interchip links [2] and interboard systems [3,4], where light is relayed via either single channel microlenses or microlens image relays. However, a point-to-point link can also incorporate a complex remapping of the parallel data array, as demonstrated in reference [2] in order to perform information processing tasks.…”

“…constructed (see Figure 1(a)) [4,19,20]. However, whilst this approach was well suited to 'demonstrator' systems, it was not obvious whether it could be extended to a manufacturable system.…”

Optical link optimization using embedded forward error correcting codes

“…The Canadian government has funded a 10-year national program to develop the architectures and technologies for a multiterabit free-space optical backplane, and a system demonstrator is described in [8]. As part of the architectural innovation, the use of simple embedded FEC built directly onto a 2-D CMOS/VCSEL optical transceiver was proposed in [6].…”