Britannica Online
Britannica Online is no longer free--you must sign up for a subscription, or make use of the 14-day free trial. Note: the IPL does not normally list fee-based sites in this collection; however, we get so many requests to list Britannica, so here it is.

 

 

Encyclopedia of Laser Physics and Technology

This is a freely accessible encyclopedia, explaining in-depth the terms and principles of topics such as laser physics, nonlinear optics, and fiber technology. The articles are arranged alphabetically by topic, and includes reference citations for further research.

 

 

 

 

Science and Engineering Encyclopedia

Definitions of science and engineering terms and math terms. Calculation help available.