The Optical Turing Machine (OTM) is an approach to digital optical processing that supports computation in the same format used for high-speed transmission. This talk identifies the key capabilities required to support native digital optical processing for typical in-network functions including forwarding, security, and filtering. Current analog and binary digital approaches – including optical transistors – are considered and shown insufficient for optical networks. The requirements for developing optical communication and computation using a single encoding are presented, as are the capabilities required for network computation. Recent results in regenerating N-PSK signals using non-degenerate PSA and multilevel amplitude squeezing are presented, with an analysis of several alternate approaches and their compatibility with optical computation. OTM was motivated by the need to support optical Internet routing, and this talk also presents the design for such a router based on decomposing the steps required for IP packet forwarding. Implementations of hop-count decrement and header matching are coupled with a recent simulation-based approach to variable-length packet merging that avoids recirculation, resulting in an all-optical data plane. A method for IPv4 checksum computation is presented and the implications of this design are considered, including the potential for chip and system integration.
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