Uncooled Laser to Contribute to Energy Conservation in Next-Generation High Speed Optical Communications Equipment

(*1): As at 24th September 2008, for uncooled laser for 1.3I 1/4m wavelength. (Hitachi survey)

"This accomplishment is an important development in achieving energy-efficient, low-cost 40Gbit/s ultra-high-speed optical transceivers," said Dr. Masahiro Aoki, department manager, Nanoelectronics Research Department, Central Research Laboratory, Hitachi, Ltd. "Uncooled lasers are a key component, as they contribute to the handling of larger data volumes, as well as, the lowering of costs in optical transmission equipment which will be required with further developments in an IT-oriented society."

The recent explosion of high-speed Internet connection and related services is expected to drive the demand for even faster communication speeds, doubling every eighteen months. Accompanying this increase in communication traffic has been a surge in the power required by optical communications equipment. It is predicted that by 2010, the core network will require the equivalent power of ten nuclear power plants.(*2) In this age where reducing CO2 emissions is a critical issue, not only achieving high-speeds data transmission but also reducing the power consumption of optical communication equipment is in high demand. By using an uncooled laser and eliminating the need for temperature control, 10 to 20 percent power can be conserved. Thus, an optical transceiver can greatly contribute to energy-efficient ultra-high-speed optical fiber networks.

(*2): Source: Agency for Natural Resources and Energy, Japan

This technology will be presented at the 34th European Conference on Optical Communication (ECOC 2008) to be held from 21st to 25th September in Brussels, Belgium, by Hitachi and Opnext Japan, a subsidiary of the US company, Opnext, Inc.

Features of the prototype uncooled laser light source are as follows:

(1) 43Gbit/s, 10km-transmission using an 1300 nm range EA modulator integrated laser Electro-absorption (EA) modulators are a type of external modulator. Using EA modulation techniques results in less degradation of the signal waveform, thus enabling higher-speed longer-distance optical transmission, compared to directly modulated lasers. Hitachi and Opnext have been working on the development of EA modulator monolithically integrated semiconductor lasers, and past cooperation has resulted in a product capable of 40Gbit/s high-speed transmission. However, the operating wavelength of this product is 1550nm, and the transmission distance limited to 2km due to fiber dispersion. To overcome this limitation, research was conducted to develop a 40Gbit/s high-speed modulator structure which is capable of operating within a wavelength of 1300nm. This would ensure less fiber dispersion and enable 10km long-distance transmission.

(2) Use of temperature tolerant InGaAlAs (indium gallium aluminum arsenide) material in the EA modulator

In the newly developed laser light source, InGaAlAs, a temperature tolerant material was used in the EA modulator to expand the operational temperature range. Further, a semiconductor process was developed for this material to achieve a monolithically integrated modulator and laser structure similar to the conventional 1550nm device.

(OPXT-G)

About Hitachi, Ltd.

Hitachi, Ltd., (NYSE: HIT / TSE: 6501), headquartered in Tokyo, Japan, is a leading global electronics company with approximately 390,000 employees worldwide. Fiscal 2007 (ended March 31, 2008) consolidated revenues totaled 11,226 billion yen ($112.3 billion). The company offers a wide range of systems, products and services in market sectors including information systems, electronic devices, power and industrial systems, consumer products, materials, logistics and financial services. For more information on Hitachi, please visit the company's website at http://www.hitachi.com.

About Opnext, Inc.

From the latest communications networks to new security systems, and from major advances in medical systems to high-demand consumer electronics, Opnext (NASDAQ:OPXT) laser technologies add the spark of innovation to a world of new applications. The company's industry expertise, future-focused thinking and commitment to research and development combine in bringing to market solutions that are ready for the next generation of laser-based products. Formed out of Hitachi, Opnext has built on more than 30 years of experience in advanced technology to establish its broad portfolio of solutions and solid reputation for excellence in service. For additional information, visit www.opnext.com.

Information contained in this news release is current as of the date of the press announcement, but may be subject to change without prior notice.

SOURCE: Hitachi, Ltd. and Opnext, Inc.

Hitachi, Ltd. Central Research Lab. Tomiko Kinoshita, +81-42-327-7777 tomiko.kinoshita.xj@hitachi.com or Opnext, Inc. Rebecca B. Andersen, +1-732-544-3338 RAndersen@opnext.com