Paul Kessler Rosenberg

A High-Speed Optical Multi-Drop Bus for Computer Interconnections

Buses have historically provided a flexible communications structure in computer systems. However, signal integrity constraints of high-speed electronics have made multi-drop electrical busses infeasible. Instead, we propose an optical data bus for computer interconnections. It has two sets of optical waveguides, one as a fan-out and the other as a fan-in, that are used to interconnect different modules attached to the bus. A master module transmits optical signals which are received by all the slave modules attached to the bus. Each slave module in turn sends data back on the bus to the master module. Arrays of lasers, photodetectors, waveguides, microlenses, beamsplitters and Tx/Rx integrated circuits are used to realize the optical data bus. With 1 mW of laser power, we are able to interconnect 8 different modules at 10 Gb/s per channel. An aggregate bandwidth of over 25 GB/s is achievable with 10 bit wide signaling paths.

A High-Speed Optical Multidrop Bus for Computer Interconnections

Signal integrity constraints of high-speed electronics have made multidrop electrical buses infeasible. This high-speed alternative uses hollow metal waveguides and pellicle beam splitters that interconnect modules attached to the bus. With 1 mw of laser power, the bus can interconnect eight modules at 10 gbps per channel and achieves an aggregate bandwidth of more than 25 gbytes per second with 10-bit-wide signaling paths.

Low cost, injection molded 120 Gbps optical backplane

A low cost, blind mate, injection molded optical backplane is presented. The optical backplane consists of a 12 channel optical broadcast bus operating at 10 Gbps/channel with six blind mate optical output ports spaced 1U apart.

Low Cost, Injection Molded 120 Gbps Optical Backplane

A low cost, blind mate, injection molded optical backplane is presented. The optical backplane consists of a 12 channel optical broadcast bus operating at 10Gbps/channel with six blind mate optical output ports spaced 1U apart.

Universal Photonic Interconnect for Data Centers

Tb/s class, co-packaged CWDM optical engine based on 4 wavelength VCSELs around 1μm is presented. The capability to scale bandwidth and link distance > 2km using single mode VCSELs and standard SMF28 fiber is demonstrated.

OPTOPUS: Optical Backplane for Data Center Switches

An all optically connected data center switch with a Multi-Bus Optical Backplane is demonstrated. The broadcast bus is based on a multimode zig-zag star coupler capable of 1:6 optical broadcast on 12 multi-mode GI fiber channels.

CWDM transceiver for mid-board optics

The need for additional IO bandwidth for data center device interconnection is well established. Optical interconnects can deliver required bandwidth along with energy and space efficiency at a cost that encourages adoption. To this end, we are developing an optical transceiver incorporating multimode VCSEL emitters in a coarse wavelength division multiplex (CWDM) system capable of transmission at 25Gbps per channel, 100Gbps/fiber, and a maximum aggregate bidirectional data rate of 1.2Tbps. Electrical connection to the transceiver can be made by solder reflow or LGA connector, and optical connection is made by means of a custom optical connector supporting CWDM transmission.

Progress towards low cost Tbps optical engines

A low cost Tb/s class CWDM optical engine prototype based on four different wavelength VCSELs around 1um is presented. 100Gbps operation per fiber is demonstrated.

2D optoelectronic engines with wafer scale self-aligned optical cores

A 24 channels (2×12) surface mount, solder reflowable, optoelectronic engine using MEMS manufacturing techniques, wafer scale packaging, and passive alignment is presented. A fiber optic link operating at 16.5 Gbps/channel was demonstrated.

Injection molded optical backplane for broadcast architecture

A low cost, blind mate, injection molded optical backplane is presented. The optical backplane is comprised of 12 channel optical broadcast buses, operating at 10Gbps/channel with six blindmate optical output ports spaced 1U apart.