of 50 Completed ATP Projects
Report - Number 2
NIST SP 950-2
4 - Electronics, Computer Hardware & Communications
Light Signals in an Optical Fiber
the last two decades, the use of optical fiber as an alternative to
metal wire and cable has exploded. Optical fiber is now the technology
of choice for use undersea and for most terrestrial applications of
more than the shortest distances.
(Based on a four star rating.)
More Light Signals
Per Optical Fiber
This ATP project with Accuwave Corporation, a small California company
specializing in the development of holographic communications systems,
created a way to substantially increase the number of signals that can
be transmitted in a single strand of fiber-optic cable. The new technology
is designed to enable the transmission of 80 or more channels per fiber.
If adopted, it could eventually reduce the cost per transmission and save
hundreds of millions of dollars over a period of just a few years.
A Unique Holography-Based
The new technology is based on the concept of wavelength division multiplexing
(WDM), which transmits light of more than one wavelength through a single
optical fiber, separating the individual wavelengths at the receiver.
Such systems must discriminate among the different wavelengths and so
are limited by the accuracy of the multiplexing and demultiplexing optics.
Accuwave had previously
developed a unique approach to WDM using volume holography: holograms
written in the interior of thick crystals of photorefractive
(light-bending) materials. In the demultiplexer crystal, for example,
multiwavelength light enters one end of the crystal and encounters a series
of holographic gratings each tuned to deflect a specific wavelength
of light that separate the light signals of different wavelengths.
Accuwave had demonstrated the individual elements of a system that could
multiplex wavelengths more than 10 times better than the current state
of the art at visible wavelengths. With its ATP funding, Accuwave extended
its technology to the infrared wavelengths used for long-distance telecommunications,
and designed a prototype WDM system.
report that ATP funding enabled it to develop WDM for signal transmission,
a task it would otherwise have been unable to do. In addition, receiving
the ATP award helped the company form important alliances with research
partners during the ATP project (not identified here for confidentiality
Spurs Alternative Commercialization
Near the end of the ATP funding period, while Accuwave was trying to raise
additional private capital to complete the technical work on its WDM system
and sign commercialization agreements with potential customers, another
company beat it to market with a competing system operating in the same
infrared wavelengths. Nonetheless, Accuwave continued to work toward completion
of its WDM multiplexer, which it believes provides multiplexing capabilities
of higher signal accuracy, with more channels per fiber and in a smaller
package than the products offered by competitors.
did not succeed in its original commercialization plans for sale of a
WDM system in the bulk-signal-transmission market, it launched several
component products based on the ATP-funded technology. These include wavelength
controllers, wavelength lockers, and fiber-optic collimators, all of which
are being sold to producers of WDM systems. The company developed contacts
with potential telecommunications clients in Europe, Japan, and Brazil,
as well as the United States, and it planned to introduce its own wavelength
multi-plexers in the near future.
Potential Big Savings
With its potential to increase the number of signals that a single optical
fiber can carry, the Accuwave technology could significantly affect the
cost of communications via fiber-optic cables, particularly if used for
Because of the volume of messages transmitted via this medium, cost savings
would be great, even if the number of signals per fiber were doubled.
The Accuwave technology has the potential to double and redouble the number
of signals per fiber many times over, with the count possibly reaching
as many as 80 signals per fiber.
In addition to applications
in the bulk-signal-transmission market, the ATP-funded technology has
the potential of providing greater cable bandwidth to homes and offices
for use with high-definition TV and to the closed-circuit TV market, particularly
for security uses. The company was interested in pursuing these potential
applications, but instead used its resources to develop the WDM system
for telecommunications applications. The technology also has potential
applications in ultranarrow band filters, spectrometers and optical disk
As this report was
going to press in late 1998, it was learned that the company had ceased
operations and was in the process of declaring bankruptcy. It is possible
that the technology will be picked up by other companies and carried forward
in the future.
To develop holographic-optics technology that will increase (by
more than 10 times) the number of signals that can be transmitted
through a single optical fiber.
Duration: 3/1/1993 3/14/1995
ATP Number: 92-01-0055
Accuwave developed a process for producing photorefractive materials
suitable for fiber optics telecommunications applications. The company
two patents for technologies related to the ATP project:
Photorefractive Systems and Methods (Divisional)
(No. 5,684,611: filed 6/6/1995, granted 11/4/1997) and
Wavelength Stabilized Laser Sources
Using Feedback From Volume Holograms
(No. 5,691,989: filed 9/14/1993, granted 11/25/1997);
- applied for
two additional patents for technologies related to the ATP project;
pilot production of wavelength division multiplexing (WDM) components
designed for incorporation into equipment manufactured by other
companies, and introduced the components in 1996;
- signed a
purchase agreement with a major telecommunications equipment manufacturer;
- raised $4
million from venture capitalists and other investors since 1990;
- built a
plant and ramped up volume production in 1998.
BY OTHERS OF PROJECTS PATENTS: See Figure
In 1996 and 1997, Accuwave introduced three WDM system components:
wavelength controllers, wavelength lockers and fiber-optic collimators.
The company continued to pursue its original goal of selling WDM
products for fiber optics telecommunications applications.
Despite the heretofore promising prospects for growing applications
of this technology in the telecommunications sectors, the commercialization
outlook at this time is bleak. As this report was going to press
in late 1998, it was learned that the company had ceased operations
and was in the process of declaring bankruptcy. While it is possible
that the technology will be picked up by other companies and carried
forward in the future, at this point there is insufficient information
about the likelihood of this to comment further on the outlook.
1651 19th St.
Santa Monica, CA 90404
Phone: (310) 449-5540
Number of Employees: 5 at project start, 16 at the end of
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Date created: April
April 12, 2005