Sabeus Adds Mode-Coupling Patent to Growing Portfolio of High Concept Technologies.

Business Editors/High-Tech Writers

CHATSWORTH, Calif.--(BUSINESS WIRE)--June 13, 2002

"Connectionless" Optical Coupling Seen as an Enabling Technology for

Low-cost Device Manufacture

Sabeus Photonics, Inc, the technology leader in the design and manufacture of high-concept optical components, today revealed details of its novel "mode-coupling" technology that promises to dramatically reduce the cost of manufacturing certain components for use in the optical communications network. The technology was recently granted U.S. Patent No. 6,360,038, adding to Sabeus' growing portfolio technologies that achieve precise or complex results using elegant and deceptively-simple methodologies.

Mode coupling provides a selective means for light traveling through an optical fiber to be forced to jump to a physically-adjacent fiber or other optical "waveguide" such as a chip, and continue entirely in the second medium, with virtually no loss in power. The effect can be engineered to apply to light of specific wavelengths while ignoring others, thus making the technology extremely valuable for use in DWDM (dense wavelength-division multiplexing) applications. In such uses, where dozens-to-potentially-hundreds of separate optical communications channels share a single fiber, separated only by the wavelength -- or color -- of the light, forcing particular wavelengths to jump from fiber to fiber can be used to implement precise but extremely low cost multiplexers or de-multiplexers.

However, according to the company, the major promise of the technology is to provide a "connectionless" interface between an optical fiber and a chip or other non-fiber optical device, eliminating the need for "pigtailing" and expensive physical alignment during manufacture.

"50% to 90% of the manufacturing cost of many optical components, such as semiconductor optical amplifiers or planar lightwave circuits (PLCs) comes from the need to provide a low-to-no loss interface between a fiber and an optical element, such as a semiconductor chip," says Dmitry Starodubov, chief technology officer and co-founder of Sabeus. "Our mode-coupling technology will make this as simple as surface mounting is in electronics -- simply lay the chip across the fiber and the optical connection is made."

According to Starodubov, today, to fabricate a packaged component such as a semiconductor optical amplifier, manufacturers must take short pieces of cut fiber, affix a tiny collimating lens to one end of each, and then mount these "pigtails" inside a package, precisely and rigidly aligned with each end of the amplifier chip. Since the angle and position of the light projecting out of or into the end of the fibers have to be held to near-impossible tolerances, it is not unusual for this single manufacturing step to add several hundred dollars to the cost of a finished device. "This is unreasonable," said Starodubov, "when you consider that in a few years, the cost of the chips themselves will probably be a few dollars, at best."

Sabeus Mode Coupling

Sabeus mode coupling provides a means for the light traveling inside an optical fiber to jump to an adjacent fiber, or, alternatively, to an adjacent chip, with virtually no loss in power.

Optical fibers consist of an ultra-transparent optical glass core, a hair-like thread through which the communications data normally flows, end to end, carried in pulses of light at different wavelengths. The core is surrounded by a transparent cladding, also usually of glass, and somewhat greater in cross section than the core. Outside of the cladding is a thin coating of protective plastic.

In typical use, light only travels down the fiber in a single mode -- end to end -- remaining entirely in the core.

However, by selectively and precisely changing the index of refraction of the core in predetermined locations, the light, or specific wavelengths of light, can be made to refract or "bend" out of the core and into the cladding, or even out of the cladding and into the surrounding environment. If you then place two similarly-prepared pieces of fiber adjacent to one another, say within 1 millionth of a meter (1 micron), the light jumping out of one fiber can be captured entirely by the other, effecting near-lossless coupling.

The same technique can be used to couple light in a fiber into an adjacent chip such as a semiconductor optical amplifier, or some other type of planar waveguide. In this case, the chip or waveguide is simply held against the side of the fiber, perhaps mechanically bonded inside a package, and the desired frequencies of light are refracted as required from one medium to the other. This high concept solution lends itself to low cost, automated manufacturing, and can make the cost of getting data in and out of the fiber insignificant.

The Sabeus mode-coupling patent makes 44 specific claims and provides for several alternatives for accomplishing mode coupling.

Mode coupling is an example of Sabeus growing portfolio of intellectual property and manufacturing expertise for high concept optical devices. A realization of Sabeus' mantra of "less is more," high concept technology uses unique understandings of the physics of light and materials to accomplish extremely difficult or precise results with elegant -- and deceptively simple -- means. Sabeus' goal is to utilize high concept optical technology to effect lasting economic and technological changes in a wide number of areas, not just limited to communications. In particular, the company is developing technology that will enable advances in aerospace, geosciences, structural engineering, and other important fields.

In addition to being a technology innovator, Sabeus has become, in a very short period of time, a preeminent manufacturer of several high-precision, cost-effective, in-fiber optical components used by Lucent, Marconi, and other major optical equipment vendors.

About Sabeus Photonics, Inc.

Sabeus was founded in 1998 by a small team of internationally-recognized U.S. and European scientists, engineers and manufacturing technologists who co-developed the company's breakthrough products as well as its sophisticated manufacturing software. The latter gives Sabeus an unparalleled ability to custom-manufacture each component to a specific customer requirement on a computer-controlled, high-volume production line. The company has applied for or has received 15 patents.

Sabeus is located in Chatsworth, CA. Investors include Agere Systems, Inc., TL Ventures, Redpoint Ventures, Digital Coast Ventures, Credit Suisse First Boston, and Lexington Ventures. Total equity investment to date is $26 million.

Editors' Note: All trademarks and registered trademarks are those of their respective companies.

Additional background information is available at www.roederj.com.