BREAKTHROUGH SINGLE-CHIP LINEAR OPTICAL AMPLIFIER HERALDS NEW ERA IN OPTICAL NETWORK EQUIPMENT ECONOMICS

Source: Genoa Corp.

100x Size Reduction, Cost Make World s First Multi-wavelength, Chip-based Optical
Amplifier Design-critical for Metro DWDM Optical Network Equipment

FREMONT, CA. Genoa Corporation, a next-generation optical semiconductor company in
Fremont, CA, announced today the world s first single-chip, linear optical amplifier (LOA) - a small, cost-effective
semiconductor device capable of amplifying light in optical communications networks. The LOA
represents the first semiconductor-based optical or "photonic" amplifier able to simultaneously amplify
dozens of different wavelengths of light without distortion, even if those wavelengths are unpredictably
switched in and out of the communications path. The tiny chip, which, when packaged, is about the size of a
sugar cube, is expected to find wide application in optical network equipment ranging from optical cross-connects,
high-speed routers, optical add-drop multiplexers, transponders, and DWDM systems, particularly in
metropolitan applications.

"As the expansion of optical networks into metro applications gains momentum," said Scott Clavenna,
president of PointEast Research, LLC, "an effective, low-cost, distortion-free means to amplify light is
becoming crucial. Network equipment manufactures do not have the luxury of using current technology,
which is often mismatched both technically and economically with the needs of the metro service providers.
Orders of magnitude reductions in cost, footprint, and power are needed almost immediately."
The problem, said Clavenna, is that photonic equipment - that which manages photons of light rather
that electrons - has not yet made the equivalent leap that electronics did following the invention of the
transistor amplifier in 1948. It was that tiny amplifier in fact - a small semiconductor crystal capable of
accurately boosting weak electrical signals - that ultimately led to today s 40-million transistor integrated
circuit, and gave rise to the modern era. "What has been missing," said Clavenna, "is the optical equivalent
of that transistor - a well behaved, linear optical amplifier built as a microchip."

Today s announcement marks the first time that "equivalent" device has ever been produced. Just
like the silicon transistor, the linear optical amplifier is manufactured on a semiconductor chip - in this case
Indium Phosphide, using a planar manufacturing process. Planar fabrication ultimately will allow more than
one optical amplifier - and later other integrated optical devices - to be simultaneously manufactured on the
same chip. Such manufacturing techniques resulted in the revolutionary integrated circuit, and are a
requirement to the ultimate attainment of the much anticipated optical IC.

The LOA is capable of the crosstalk-free amplification of lightpaths containing dozens or more
channels encoded in different wavelengths - or colors - of light. It also is free of distortion when used in a
switching environment, where the number of channels carried on the lightpath from moment to moment is
unpredictable.

These two characteristics are of vital importance to equipment designers and service providers.
Today s high-speed optical communications networks gain their impressive capacity by the sharing of single
fiber-optic strands by dozens - and increasingly hundreds - of different channels encoded by wavelength, a
methodology called "dense wavelength division multiplexing," or "DWDM." Consequently, for any optical
amplifier to be useful in all but limited single-channel applications, it must be able to amplify DWDM signals
without crosstalk. That is, the amplifier s output must be an exact - or "linear" copy of its input. Crosstalk is
a phenomenon familiar to cell phone users whose reception is occasionally garbled by the mixture of several
other calls. It can similarly garble optical communications. Previous attempts at single-chip optical
amplifiers have failed to solve this problem.

Additionally, practical networking applications, particularly in the fast-growing metropolitan
networks, need to be able to quickly switch different wavelengths in or out of single fibers without impacting
the fidelity of the communications - a task which previous technologies are struggling to accommodate.
The linear optical amplifier meets both these requirements, as well as being 1/100 th the size of
current technology.

Amplification in the Optical Network
Amplifiers take small signals and boost them - higher current, higher voltage, or in the case of optical
communications networks, brighter pulses of light. They have always been crucial because, in part, the
farther signals have to travel - whether electronic or photonic - the weaker they get. Additionally, traveling
through even the most carefully constructed networking equipment causes losses - especially with light - that
must be made up.

In the optical network, which until recently was used predominantly for inter-city, intercontinental
"long-haul" applications, signals have to be amplified every 50 to 80 kilometers, as the fibers that carry the
photons gradually absorb them. Such amplification has traditionally been provided by a device called an
EDFA, for "erbium-doped fiber amplifier." The EDFA is a complex hybrid optical and electronics module -
about the size of a videocassette - that costs anywhere from $5,000 to 30,000. One EDFA is required for each
fiber needing amplification.

Like the LOA, the EDFA can amplify DWDM signals without crosstalk. However, unlike the LOA, it
cannot reliably be used in most switching applications, or designs where the engineer cannot closely control
the total power of the signals - precisely the types of requirements needed in metropolitan optical network
equipment. Indeed, in "metro" networking equipment, such limitations and the workarounds they create,
combined with the EDFA s large size and extreme cost, make its use impractical. And yet, amplifiers will be
of crucial importance to metro networking equipment.

The LOA
The linear optical amplifier is a single-chip, semiconductor-based amplifier that is to the EDFA-type
optical amplifier what the transistor was to the vacuum tube. Like the transistor, it is tiny; a single LOA chip
is about 1 millimeter square. Even when packaged in its typical enclosure, it is about the size of a sugar
cube. By contrast, the EDFA is 100 times larger.

According to Rick Gold, president and CEO of Genoa, the LOA is ideal for metropolitan optical
networking equipment. "The same pace of integration that the electronics industry enjoyed from 1959 -
when the multi-transistor IC was invented - until today will rapidly become mission-critical for photonics, which
comparatively, is today still in the Dark Ages. Nowhere will rapid integration, vast cost reduction, and
totally new design strategies be more important than in the exploding metro market."

The LOA is the much-anticipated breakthrough, said Gold. "Like the transistor amplifier before it, the
LOA is disruptive technology - technology that enables profoundly novel and totally unforeseen design
approaches for both old and new problems." PointEast s Clavenna agrees. "The linear optical amplifier will
finally enable the design of appropriately-priced, compact, and inexpensive-to-operate metro networking
equipment." According to a November 2000 report from RHK, spending for such equipment will exceed $11.4
billion in 2004.

How the LOA Works
Semiconductor-based optical amplifiers amplify light as it passes through a crystal such as
Indium Phosphide according to the same quantum-mechanical principles that make a transistor work.
However, such light amplifiers have an inherent defect: introducing a second signal into the
semiconductor while it is amplifying another wavelength will cause the amplified version of each signal
to take on some of the characteristics of the other. This is crosstalk.

Crosstalk between multiple wavelengths occurs because each signal passing through the
semiconductor varies, or "modulates" the amplifier gain - that is, the amount of amplification - as seen
by the other signals. The net result is that each signal takes on some of the characteristics of the
others. The resulting distortion is quite similar to that encountered by digital cell phone users who
experience the wireless equivalent of "crossed wires." In optical communications, crosstalk renders
the output signals unusable.

The linear optical amplifier avoids this problem by pumping a virtually unlimited supply of
photons - the particles that make up light - into the heart of the amplifier, using a laser. Like the tons
of lead in the keel of a sailboat that ballasts it against gusts of wind, the ballast laser perfectly
counteracts the tendency of the semiconductor to react adversely to "gusts" of photons - the incoming
signal pulses - and, ultimately, keeps the gain of the amplifier perfectly constant, or "linear." In a
linear amplifier, output signals are absolute, faithful copies (within required design limits) of the
original inputs.

What is unique about the Genoa linear optical amplifier, and the crux of Genoa s breakthrough,
is that the ballast laser is built right into the chip itself. Using a unique process invented by Genoa s
founders, the amplifier and the ballast laser are manufactured simultaneously as one monolithic
structure in Indium Phosphide. In actual operation, the multiple-wavelength signals to be amplified
pass horizontally through the chip, directly through the path of the laser, which is busily pumping
photons of light vertically in the same chip. As previously described, the ballast photons precisely
counteract signal-induced variations in the gain of the amplifier, making it linear.

Genoa s LOA chip, with its intrinsic vertical-cavity, surface-emitting laser, is a unique, new
type of semiconductor structure. It is the subject of numerous pending and granted patents. The
technology is expected by Genoa to ultimately be viewed as an enabling technology for true optical
ICs.

"Genoa s product is aiming at one of the most important challenges in optical networking - the
signal loss caused as extra functions are added," said Dr. John Ryan, principal and chief analyst at RHK.
"The kinds of amplifiers used in optical networks now are too expensive to use in short-distance, metro
network applications, or inside optical equipment. Genoa s single-chip products are a major step in
resolving this."

Availability and Pricing
Customer tests of the new Genoa Linear Optical Amplifier are currently underway and
commercial samples will be available later this year. Pricing has not been set as of press time. First
products will be available in an industry standard 14-pin butterfly package.

About Genoa Corporation
Genoa is a next-generation optical semiconductor company that has made fundamental
breakthroughs leading to the design and manufacture of well-behaved, single-chip linear optical
amplifiers. Genoa s disruptive LOA technology is expected to revolutionize the economics of major
segments of the optical communications industry by permitting levels of system integration previously
only enjoyed by purely electronic products.

Genoa s first product is the Genoa linear optical amplifier, a well-behaved, single-chip indium-phosphide
linear optical amplifier optimized for use in metropolitan optical network applications. The
Genoa LOA replaces contemporary optical amplifiers 100 times as large with a simple, reliable, cost-effective
device suitable for use in the today s demanding dense wavelength-division multiplexing
(DWDM) applications.

Genoa s unique, indium-phosphide-based linear optical amplifier technology is the subject of
several dozen fundamental issued or pending design and manufacturing patents. The company, with
80+ employees, has research, development, wafer fabrication and manufacturing facilities at its
Fremont, CA, headquarters, and in Eindhoven, The Netherlands. Funding to date is approximately $95
million; investors include August Capital, Bessemer Venture Partners, Global Crossing, Investor AB,
Levensohn Capital, Meritech Capital Partners, Oak Investment Partners, and WorldCom Ventures.
Genoa was founded in 1998 by leaders in optical amplifiers and semiconductor lasers.

GENOA CORPORATION
41762 CHRISTY STREET
FREMONT, CA 94538
(510) 979-3000 FAX: (510) 656-6731
www.GENOA.COM

For more press information contact:
Abigail Johnson/Paul Michelson
Roeder-Johnson Corporation
(650) 802-1850
abigail@roederj.com/paul@roederj.com

For more product information contact:
Genoa Corporation
Fremont, CA
(510) 979-3000 /Fax: (510) 656-6731
info@genoa.com