Analog-Faster-Cheaper-BetterAn Optical Signal Processing View

Terry Turpin

Chief Scientist Essex Corporation

Turpin@essexcorp.com

Facts

• The “The Universe” is analog• Human technology is still mostly analog

– (did you ever see a digital bicycle)• Digital has dominated the information processing and

communications world for more than three decades• Analog processing has been ignored by educational

institutions• There are at least two generations of scientists and engineers

that have never learned analog processing or communications technology

• Analog optical processing in the past as been a small but persistent exception

• Optical communications and analog optical processing are merging the same way that digital processing and digital communications did in the past

Processing Overload

World of Analog Signals

AA

to to

DD

Digital Stream

17,905,340 Tbs!!

(2002 Data!)

Spread Spectrum

Fiber Optic

Microwave

Land Lines

Radio 3,488 Tbs

Television 68,955 Tbs

Telephone 17,300,000 Tbs

Internet 532,897 Tbs

So much information… so little time to process itProcessing power is the key to superiority in a world market

The Information Superiority Problem

Summary of electronic information flows of Summary of electronic information flows of new information in 2002 in terabytesnew information in 2002 in terabytes

… … 17.7 exabytes each year, and growing17.7 exabytes each year, and growing

“Era of Tera”*

*Pat Gelsinger, CTO Intel (Keynote address at Intel Developer Forum Feb 2004)

… a Digital Perspective

Digital Dilemma over Power“Power density is increasing at a rate that implies that

tens of thousands of watts per centimeter (w/cm2) will be needed to scale the performance of Pentium processor architecture over the next several years. But that would

produce more heat than the surface of the Sun…”*

*Pat Gelsinger, CTO Intel (Keynote address at Intel Developer Forum Feb 2004)

… Begins the Age of Optical

*Pat Gelsinger, CTO Intel (Keynote address at Intel Developer Forum Feb 2004)

Optical Processors

*

References to Optical Processors added by Essex Corp.

Analog Optical Processors excel at - Images - Signals - Correlations

Analog Optical Processing Overview

Performance/Application

SometimesSometimesBetter

Watts/cm2AlwaysAlwaysCooler

Bytes/$YesSometimesCheaper

TIPSYesYesFaster

Measured ByFutureToday

Optical Processing

An Unclassified Success in Size, Weight and Power

• Acousto-Optic Spectrometer AOS launched late 1998 on SWAS for a 2 year mission

• 4 channel 1400 point Fourier transform in real time on a 1.4 GHz analog signal

• Compute power is 500 Gigaflops (Sustained) for 12 Watts electrical power

• Analog input eliminated the need for high speed A/D converters

• Mission to study the chemical composition of interstellar clouds

• SWAS would be impossible without the AOS optical computer

Optical Processor/Computer?

Functions most frequently used•Fourier Transform (demultiplexing/multiplexing)•Correlation (pattern detection)•Data distribution and replication

… a machine that performs

mathematical functions with light rather than

electrons

Why go to Analog Optical Processors?

• Speed

• Reduced size and power consumption

• OEO Overhead & Cost are Excessive (optical - electrical - optical)

• Natural Fit: Optical Processing for

- Optical Communications- Images- Signals- Correlations

• Typical improvement is a factor of 50000

AdvantagesAdvantages

Information on Light

• Information is carried by the complex-valued property of light (spatial frequency, amplitude and phase)

• When an information-carrying beam is passed through a special lens or coating, or interfered with another reference beam, light performs mathematical functions

Massive Parallelism

• Operates simultaneously on an entire wave front and more than one variable — e.g., direction, amplitude and phase

• Digital systems are serial in nature

• Example: A lens simultaneously acts on the entire light beam

Computational Set

• Analog optics can perform mathematical functions– add – copy – multiply – Fourier transforms – correlation – convolution

• Operates on one- and two-dimensional arrays of numbers in parallel

• A single analog optical computer “instruction” might require thousands or millions of individual instructions for a conventional computer

Analog Optical Computing

Smaller,Lower Power,Lighter Computers

Many Parallel Electronic

Processors

Optical Computational

Module

Combines the best of both worlds:precision of electronics withmassive computational power of light.

Vs. Supercomputer power where it can’t go now. • Head of a missile• UAV• Mobile ICBM Defenders• Satellites

12 inches square

Cutting Edge Elements

Materials

•Photonic Crystals

•Non-Linear Materials

•Silicon Germanium

•III-V & II-VI Materials Systems•VCELS•Optical Fiber•Optical Amplifiers

•SOA•EDFA

•Optical Correlators•Optical Signal Processors

New Components

Technology•Photon Echo•Optical Tap Delay•Solotons

Example: Analog Optical Encryption

• Digital Encryption– ATM at 10Gbps soon

– No 40 Gbps on horizon

– Protocol specific

– Cost increases linearly with number of signals on a fiber

• Analog Encryption– 5000 Gbps on horizon (ESSEX Eclipse Module)

– Potential for multi-band encryption (L,C, and S)

– Protocol agnostic

– Cost is market driven and grows slowly with capacity on a fiber

– 100 Teraflops for less than 10 Watts of electrical power

Hyperfine Analog Optical Encryptor

Hy

pe

rfin

e D

ev

ice

Phase Key Control

Computer

Phase Key Control

Computer

…

Sub-channelsSub-channels

Analog DecodingAnalog Decoding “ “key”key”

Sub-channelsSub-channels

X GbpsX GbpsWD

M

Dev

ice

X Gbps Device

oror

C Band Comms DeviceC Band Comms Device

Hy

pe

rfine

De

vic

e

…Analog Encoding

“key”

Point APoint A

Point BX GbpsX Gbps

X Gbps Device

WD

M

Device

C Band Comms C Band Comms DeviceDevice

oror

Reflective Phase Reflective Phase Modulator ArrayModulator Array

Reflective Phase Reflective Phase Modulator ArrayModulator Array

How Does it Work?

InputInput

TransmittedTransmitted

RecoveredRecovered

Scrambled PhotonsScrambled Photons

Simulated DataSimulated Data

Terabit Security – Cost Perspective

*

*

*Assumes that aggregate bandwidths *Assumes that aggregate bandwidths above 10 Gbps will be encrypted using above 10 Gbps will be encrypted using multiple 10 Gbps encryptor pairs – 1 multiple 10 Gbps encryptor pairs – 1 pair per wavelength pair per wavelength

** ** Estimated Estimated costs are based on a multiplexed costs are based on a multiplexed optical signal with aggregate bandwidth as optical signal with aggregate bandwidth as indicated, and single optical encryptor pair per indicated, and single optical encryptor pair per optical linkoptical link

****

Additional Advantages

• Analog optical processing provides an alternate approach to thinking about problems

• This alternate approach often leads to solutions that are radically different and sometimes better

• For example, to implement continuous scale change and Fourier transforms on data that has not been sampled or digitized

• Enable solutions to problems that are thought to be too complex to solve economically

• In supercomputing applications the improvement is about a factor of 50000

Summary

• Analog is faster, cheaper and better• Examples are

– Separating signal channels in frequency– Optical Encryption– Optical Communications– Optical Signal Processing

• Analog is a key technology• Analog optical technology will force analog electronics

because of the A/D conversion limitation• In optical communications, analog encryption and

wavelength routing will provide growth at low cost per terabit