Free space adaptive optical interconnect, using a ferroelectric liquid crystal SLM for beam steering

A free-space, board-to-board, adaptive optical interconnect demonstrator has been developed. Binary phase gratings displayed on a Ferroelectric Liquid Crystal Spatial Light Modulator are used to maintain data transfer at 1.25Gbps, given varying optical misalignment © 2005 Optical Society of America.

Cost-effective 10 Gb/s polymer-based chip-to-chip optical interconnect

Board-level optical links are an attractive alternative to their electrical counterparts as they provide higher bandwidth and lower power consumption at high data rates. However, on-board optical technology has to be cost-effective to be commercially deployed. This study presents a chip-to-chip optical interconnect formed on an optoelectronic printed circuit board that uses a simple optical coupling scheme, cost-effective materials and is compatible with well-established manufacturing processes common to the electronics industry. Details of the link architecture, modelling studies of the link's frequency response, characterisation of optical coupling efficiencies and dynamic performance studies of this proof-of-concept chip-to-chip optical interconnect are reported. The fully assembled link exhibits a -3 dBe bandwidth of 9 GHz and -3 dBo tolerances to transverse component misalignments of ±25 and ±37 μm at the input and output waveguide interfaces, respectively. The link has a total insertion loss of 6 dBo and achieves error-free transmission at a 10 Gb/s data rate with a power margin of 11.6 dBo for a bit-error-rate of 10 -12. The proposed architecture demonstrates an integration approach for high-speed board-level chip-to-chip optical links that emphasises component simplicity and manufacturability crucial to the migration of such technology into real-world commercial systems. © 2012 The Institution of Engineering and Technology.

Free space adaptive optical interconnect, using a ferroelectric liquid crystal SLM for beam steering

A free-space, board-to-board, adaptive optical interconnect demonstrator has been developed. Binary phase gratings displayed on a Ferroelectric Liquid Crystal Spatial Light Modulator are used to maintain data transfer at 1.25Gbps, given varying optical misalignment.© 2005 Optical Society of America.

Analysis of the effect of transverse modes on free-space optical interconnect performance

Vertical-cavity surface-emitting lasers (VCSELs) and microlenses can be used to implement free space optical interconnects (FSOIs) which do not suffer from the bandwidth limitations inherent in metallic interconnects. A comprehensive link equation describing the effects of both optical and electrical noise is introduced. We have evaluated FSOI performance by examining the following metrics: the space-bandwidth product (SBP), describing the density of channels and aggregate bandwidth that can be achieved, and the carrier-to-noise ratio (CNR), which represents the relative strength of the carrier signal. The mode expansion method (MEM) was used to account for the primary cause of optical noise: laser beam diffraction. While the literature commonly assumes an ideal single-mode laser beam, we consider the experimentally determined multimodal structure of a VCSEL beam in our calculations. It was found that maximum achievable interconnect length and density for a given CNR was significantly reduced when the higher order transverse modes were present in Simulations. However, the Simulations demonstrate that free-space optical interconnects are still a suitable solution for the communications bottleneck, despite the adverse effects introduced by transverse modes.