Cover Story
Photovoltaics: Lighting the Way to a Brighter Future

Sarah Kurtz and Daniel Friedman
Technology to concentrate solar energy is still under development, but could be poised for rapid growth. In fact, if the rate of progress for the current photovoltaic industry is sustained and costs come down, sunlight could become a... more>>
None
Fiber Lasers: High-Power Devices in Compact Packages
Nasser Peyghambarian and Axel Schulzgen
Fiber lasers can deliver large amounts of energy to a target in a very precise but flexible way. They have many uses in industry, defense and medicine, in addition to traditional applications in communications, spectroscopy and remote sensing. This article reviews progress that has been made with high-power and solid-state lasers, and explores the emerging role that fiber lasers play as a high-power laser source. more>>
None
Measuring the Wavelength of Light with a Ruler
Keigo Iizuka
Almost 20 years ago, Arthur L. Schawlow, the 1981 Nobel laureate, told the author that a metal ruler could be used to measure the wavelength of light. Since then, he has always wanted to verify the accuracy of such an experiment for himself. He finally has; the method and results are reported in this article. more>>