Cover Story

The History of the X-ray Laser

Jeff Hecht

The long and curious history of the X-ray laser began in an effort to expand the frontier of knowledge and culminated in one of the wildest schemes ever pursued by the United States government—the “Star Wars” missile defense initiative... more>>

Features

Directly Pumped Silicon Lasers

Jeffrey M. Shainline and Jimmy Xu

Over the past two decades, researchers have tried mightily to enhance silicon’s ability to emit light. Yet electrically pumped silicon lasers remain tantalizingly out of reach. These authors describe how the approaches that have been tried so far might be successfully combined. more>>


Electrically Pumped Photonic Crystal Nanolasers

Hong-Gyu Park, Min-Kyo Seo, Se-Heon Kim and Yong-Hee Lee

For years, the quantum optics community has been testing the limits on laser size: How small can you go? Thanks to advances in semiconductor crystal growth and fabrication techniques, the answer is now wavelength-scale. more>>


Fiber Lasers and Their Coherent Beam Combination

Qihong Lou, Jun Zhou, Bing He and Hongming Zhao

With high efficiency and exceptional beam quality, fiber lasers hold great promise. The 1-µm wavelength makes it possible for them to replace both diode- and lamp-pumped Nd:YAG lasers in the micromachining, automotive and biomedical markets. more>>