Developed as a better way to help researchers quickly get to the quality content they need, Scitopia.org (now in beta - launches in June 2007) will provide federated searching across 15 leading science and technology societies' electronic libraries, with initial access to more than three million peer-reviewed journal articles, conference proceedings, and patents covering 150 years of science.
Note that at least one of the resources requires that you register (it's free and simple).
Photonics Dictionary: contains more than 6000 industry-related terms, acronyms, abbreviations and illustrations
Photonics Handbook: technical design and applications articles; basics of photonics technology
Photonics Corporate Guide: International list of manufacturers, suppliers, and business descriptions
See also: Optics Subject GuideAdded 6/19/07
"WorldWideScience.org opens public access
to more than 200 million pages of international research information"
"The U.S. Department of Energy (DOE) and the British Library, along with eight other participating countries (see database list), has opened an online global gateway (WorldWideScience.org) science information from 15 portals. The gateway gives citizens, researchers and anyone interested in science the capability to search science portals not easily accessible through popular search technology such as that deployed by Google, Yahoo! and many other commercial search engines.
Using federated searching, WorldWideScience.org saves time by providing one entry point and one query for searching multiple science portals. In time this gateway will tap into less well-known sources of valuable science.
Science.gov, the U.S. government's portal to federal agency science databases, is included as well as research information in English from Australia, Brazil, Canada, Denmark, France, Germany, Japan and the Netherlands. The intent is for it to become a world-class Web facility that allows anyone to easily find the research of any nation in any language.Added 6/27/07