By Science News Staff

Web edition: August 10, 2012
Print edition: August 25, 2012; Vol.182 #4 (p. 4)

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RUBY LASER PIERCES A SAPPHIRE CRYSTAL — A pulsed ruby laser piercing a sapphire crystal is shown on this week’s front cover. The laser at the Radio Corporation of America Laboratories in Princeton, N.J., generates energy so intense that it can bore a sixteenth of an inch hole in the sapphire in a thousandth of a second. The heat produced at the surface of the crystal is at least 2,800 degrees centigrade. Lasers are devices that amplify light waves and emit them “in step” to form a highly directional and powerful beam of coherent light…. Their name is derived from the term, “light amplification through the stimulated emission of radiation.” Able to amplify light waves just as radio waves are amplified, lasers already foreshadow an era in which light beams may be used in guiding space vehicles and communicating between planets.