Cover Story

Optical Filters in Nature

H.D. Wolpert

Optical engineers require an array of sophisticated equipment to produce what Mother Nature creates effortlessly—optical filters that are diverse, complex and visually striking. more>>

Features

Half a Century of Laser Weapons

Jeff Hecht

Even before the laser was invented, science fiction writers saw rich potential in the use of light-beam “death rays” as powerful tools of destruction. But the real history of directed-energy weapons in the United States has been fraught with political and technical challenges and setbacks. more>>


Reflections on Total Internal Reflection

Lorne A. Whitehead and Michele A. Mossman

These authors probe some of the most fundamental approximations in optics to explore why total internal reflection is not as straightforward as it might seem. more>>