Tokyo, Japan, Jan 19, 2007 - (JCN Newswire) - Shin-Etsu Chemical Co., Ltd. (TSE: 4063), announced that it has developed a manufacturing technology for lead-free optical isolators, which enables it to comply with the European RoHS Directive (Restriction of Hazardous Substances). Until now, Faraday rotators[1], which are main component parts of optical isolators, contained lead; however, this newly developed technology has made it possible to totally eliminate the lead element in optical isolators.

In July 2006, the European Union issued a RoHS Directive on the restriction of the use of certain hazardous substances such as the lead element in electrical and electronic equipment, and in principle, the decision was made to totally abolish its use. However, due to technical difficulties in fulfilling this RoHS Directive for some components and processes, including optical isolators, which are indispensable components for optical fiber communication systems, an accommodation was made in the RoHS regulations to allow exemptions for such cases and a less absolute standard of regulating lead content to below 1,000 ppm has been planned to be adopted, although it was expected that completely lead-free optical isolators would be developed soon.

The technology that Shin-Etsu has expeditiously developed fulfills the equipment makers' expectation by achieving the total elimination of lead from optical isolators. Going forward, this new technology will enable the optical communications industry to comply with the expanding scope of environmental regulations.

Optical isolators are set in such devices as laser modules. Such isolators permit optical light that is emitted by a laser diode to be transmitted in only one direction. They are used to protect laser diodes because they block the adverse effect of return beams that go back to the laser diodes from the optical fiber transmission channels and amplifiers.

Rare-earth iron garnet single crystals with a thickness of several hundred microns, which are grown by the Liquid Phase Epitaxy (LPE) method, are used in Faraday rotators for optical isolators. In the LPE method, an oxide flux is used to melt the crystal component at a lower melting point. Until now, lead oxide was considered to be an essential material, and for this purpose, the rare-earth iron garnet single crystals contained about 5,000 ppm of lead oxide.

Shin-Etsu Chemical, by developing its own original LPE method that does not use lead oxide at all, succeeded in developing for the first time in the world the technology to grow rare-earth iron garnet crystals with a thickness of several hundred microns and reduce to zero ppm the amount of lead in Faraday rotators, which are a key component part of optical isolators.

Now that Shin-Etsu has achieved a mass-production technology for Faraday rotators that are lead-free, it will implement the total elimination of lead from optical isolators.

Moreover, Shin-Etsu Chemical is also moving ahead with the development of technology for completely lead-free rare-earth iron garnet crystals for inline isolators[2] and circulators[3]. Shin-Etsu Chemical plans to increase its production capacity to respond to demand from the optical communication parts market, which is being boosted by FTTH (Fiber to the Home) applications.

[1] Faraday rotator: An optical isolator consists of a magnetic garnet crystal having a Faraday effect, a permanent magnet for applying a designated magnetic field, and polarizing elements that permit only forward light to pass while blocking backward light. Optical isolators result in higher quality transmission performance. The plane of linearly polarized light is rotated when a magnetic field is applied parallel to the propagation direction, and this phenomenon is called, the Faraday effect. The Faraday rotator is the component part that by utilizing this effect controls the angle of light that is moving along the transmission path and also the path of the backward light.

[2] Inline isolator: A component part used in an optical amplifier to prevent any light from reflecting back down the optical fiber communication line. It helps to avoid degradation of the signal-to-noise ratio by blocking light moving in a reverse direction.

[3] Circulator: A component part that changes the path of an optical signal. Set in the optical fiber transmission channel, it plays the role of isolating an optical signal or returning it to the transmission line.

Prime Minister Shinzo Abe will pick the site for the 2008 Group of Eight summit, which Japan is hosting, in March amid an intensifying race among candidate areas.

Three areas have tossed their hat into the ring to host the summit -- Kyoto, Osaka and Hyogo prefectures which are pitching a ''Kansai summit,'' Yokohama and Niigata cities, proposing a ''port city summit,'' and Okayama and Kagawa prefectures, offering an ''Inland Sea summit.'' The Lake Toya area in Hokkaido has also emerged as a candidate venue, government sources said.


Japan has hosted the summit of major nations four times in the past -- the first three times in Tokyo, in 1979, 1986 and 1993. For the fourth occasion in 2000, Nago, Okinawa Prefecture was chosen at the initiative of then Prime Minister Keizo Obuchi and Chief Cabinet Secretary Hiromu Nonaka, becoming the first local city to host the event in Japan.

Facilities are required not just to provide accommodation for summit participants and their attendants, but also for journalists, expected to number more than 5,000. Security concerns also figure prominently for any summit site.

The G-8 groups Japan, Britain, Canada, France, Germany, Italy, Russia and the United States.

A Foreign Ministry source said, ''The summit can be held at any of the present candidate sites.'' But it is up to the prime minister what priority to use in selecting the site -- the environment, facilities, security measures or international image, government sources said.

For the 2000 summit, the five cities of Fukuoka, Miyazaki, Hiroshima, Yokohama and Sapporo as well as Osaka and Chiba prefectures competed with Okinawa to host the event. In the final stage of selection, that list was whittled down to Okinawa, Fukuoka and Miyazaki.

Obuchi finally picked Okinawa because he wanted to use the event to make a breakthrough in resolving the problem of the relocation of the U.S. Futemma Air Station in the prefecture as part of the realignment of U.S. military forces in Japan.

He also decided to hold the meeting of G-8 finance ministers in Fukuoka City and the meeting of G-8 foreign ministers in Miyazaki City. But Obuchi died before the summit was held, and his successor, Yoshiro Mori, hosted the event.

The selling point of the Kansai summit is the region's role as the ''origin of Japanese history and culture.'' In addition to having the Kyoto State Guesthouse and other facilities, the region boasts the experience of hosting a summit meeting of the Asia-Pacific Economic Cooperation forum in Osaka in 1995.

But Kyoto and Osaka prefectures are playing a tug of war with their respective proposals for the site of the G-8 summit, giving rise to fears among local officials that rival candidates may snatch the venue.

Kyoto Gov. Keiji Yamada, quoting Abe's pet slogan of creating a beautiful Japan, said, ''Kyoto is best suited if the importance of Japan's culture and environment should be highlighted at the summit,'' while Osaka Gov. Fusae Ota said it would be easy to provide security for a summit at Osaka Castle.

Both Yokohama and Niigata cities are drawing attention to their roles in Japan's modernization, saying the year 2008 is the 150th anniversary of the Japan-U.S. Friendship and Trade Treaty which led to the opening of their ports.

Yokohama hopes to host the summit in the Minato Mirai area where international conference halls and hotels are concentrated, while Niigata wants to host ministerial meetings at the complex facility Toki Messe. Both places, they said, are compact and easy for security.

Okayama and Kagawa prefectures are offering scenic Naoshima Island in the Inland Sea as a summit venue with ''easy security'' as the biggest selling point. Diet members from the prefectures have formed a league to take the initiative in bringing the summit to the island and had direct negotiations with Chief Cabinet Secretary Yasuhisa Shiozaki last October.

The town of Toyako, where one of the best resorts in Hokkaido is located, has emerged among government officials as a possible venue for the summit because of security reasons, although the town has not raised its hand.

Mayor Yoshio Nagasaki welcomed this, saying, ''It is a great honor,'' but a senior municipal government official was perplexed, saying, ''What about our financial burden? Unless we know what the state and the prefecture are thinking, we are dead in the water.''

The town has no problem about facilities for the summit, but the financial burden is the biggest hurdle because Sapporo, the capital of the prefecture, abandoned the idea of hosting the summit due to the estimated cost of more than 7 billion yen.

The Hokkaido prefectural government is in a serious financial situation and is restructuring itself. It has also been asked to financially support the city of Yubari, which has gone under.

Gov. Harumi Takahashi said there are benefits for the northern Japan prefecture to host the summit because it can also appeal to the world for the return of four islands captured by the Soviet Union at the end of World War II. But he took a cautious attitude to hosting the summit, saying, ''The financial shouldering cannot get support from residents of the prefecture.''