David Calhoun

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The rising popularity of cloud computing and big data applications has led to massive volumes of rack-to-rack traffic featuring diverse communication patterns denoted as *-cast that combines unicast, multicast, incast and all-to-all cast. Effective support of these traffic patterns in data center networks is still an open problem. We propose a hybrid(More)
With the rapidly increasing aggregate bandwidth requirements of data centers there is a growing interest in the insertion of optically interconnected networks with high-radix transparent optical switch fabrics. Silicon photonics is a particularly promising and applicable technology due to its small footprint, CMOS compatibility, high bandwidth density, and(More)
— Realizing small-footprint and energy-efficient optical switching fabrics is of crucial importance to solve the data movement challenges faced by optical interconnection networks. This letter demonstrates silicon photonic 2 × 2 full crossbar switching functionality based on a single microring. The ultra-compact device is shown to successfully switch data(More)
—Silicon photonic interconnection networks can provide significant advantages in bandwidth densities and data communication energy efficiencies over electronic-interconnected systems. However, due to the circuit switched nature of photonics, the latencies associated with circuit setup and reconfiguration must be managed to avoid added delays in application(More)
A programmable control system for wavelength locking WDM channels on microring arrays is used to demonstrate arbitrary demultiplexing and selection of fast switchable wavelengths. Successful data measurements verify the functionality within an interconnection network implementation. 1. Introduction Chip-scale optical interconnects that employ novel silicon(More)
—Optical interconnects, which support the transport of large bandwidths over warehouse-scale distance, can help to further scale data-movement capabilities in high performance computing (HPC) platforms. However, due to the circuit switching nature of optical systems and additional peculiarities, such as sensitivity to temperature and the need for wavelength(More)
iOS is Apple's mobile operating system and is presently used on the iPhone, iPad, and iPod Touch. The hardware platforms associated with the iOS operating system provide a powerful platform for sensor applications. In this paper, we provide a case study on the development of a digital multimeter (DMM) using an iPod Touch. The DMM case study addresses the(More)
We review the requirements and expectations of future Supercomputer architectures, analyse how transparent optical networking might contribute to these future systems scalable performance, and develop the most immediate challenges for optical system developers in this context. Introduction Over the past few decades, Supercomputers performance as signified(More)
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