Single Fiber Optical IO on standard 0.35 um CMOS

Nan Marie JokerstMartin A. Brooke

Duke UniversityDepartment of Electrical and Computer Engineering

email: mbrooke@ee.duke.edu

HUB

Asymmetric or symmetricbandwidth link in each direction

Home Interface

Emitter stacked on top ofdetector for bi-directional link

•Co-located, stacked thin film emitters and detectors for bi-directional interface

•Single fiber between the hub and home

•Alignment tolerant for low cost packaging

Si CMOS Receiver and Transmitter Circuits

Thin film emitterThin filmdetector

Optical fiber

Previousresult for co-locatedemitter/detector pair

Home Interface Implementation Using a Single Fiber Bi-Directional Fiber Link

Si CMOS Rxand Tx Circuits

Thin film emitterThin filmdetector

Optical fiber

• The co-location of the emitter and detector enables single fiber bi-directional communication

• For asymmetric, low cost interconnection, detector

will run at 1 Gbps, and LED emitter at ~100 Mbps.

For faster emitter, edge emitter and mirror will be

used.

Co-Located Emitter and Photodetectorfor Single Fiber Bi-Directional Link

Transceiver: Laser Driver and TIA

RCE InGaAs LED50 m diameter with 30m aperture

I-MSM GaAs PD 150 m detector diameter

Measurements from Circuit With Integrated Stacked Devices

I-MSM photoreceiver eye diagram at 1Gbps

RCE LED optical transmitter eye-diagram at 40 Mbps (LEDs are slow)