Year Of The Laser

From Technology Review:

The laser, a device used in everything from astrophysics to biology, was invented 50 years ago.

This year is the 50th anniversary of the laser, a device used in applications from performing precise surgical procedures to measuring gravitational waves. In 1917, Albert Einstein proposed that a photon hitting an atom in a high energy state would cause the atom to release a second photon identical in frequency and direction to the first. In the 1950s, scientists searched for a way to achieve this stimulated emission and amplify it so that a group of excited atoms would release photons in a chain reaction. In 1959, American physicist Gordon Gould publicly used the term “light amplification by stimulated emission of radiation” for the first time. A year later, scientists demonstrated the first working optical laser.

Read more ....

Back To The Drawing Board With Missile-Beating Laser

The Airborne Laser just can’t deliver a beam with enough power
(Image: Jim Shryne/USAF)

From New Scientist:

A laser-toting Boeing 747 blasted two missilesMovie Camera out of the sky earlier this month, but despite this apparent success the Pentagon is going back to the drawing board in its search for an anti-missile laser weapon.

The ABL's problem is that it can't deliver enough power over enough distance to be genuinely useful, so the culmination of a project begun in 1996 and costing an estimated $5 billion will be to downgrade the ABL to a "testbed". It will be handed over by the Missile Defense Agency to the US air force for general research use.

Read more ....

Building The World's Most Powerful Laser

Photo: Power up: This laser can deliver a 200-joule pulse of light lasting just 100 femtoseconds. The cables at left pump power to green flash lamps that pump the laser. Credit: Texas Petawatt Laser Project

From Technology Review:

New lasers will be key to making fusion energy and proton therapy practical.

This March, researchers at the National Ignition Facility demonstrated a 1.1 megajoule laser designed to ignite nuclear fusion reactions by 2010. But the facility's technology, which is housed at the Lawrence Livermore National Laboratory in California, cannot yet generate enough energy to drive a practical power plant. So, even as physicists look forward to next year's demonstration, they're working on even more powerful lasers that could make possible a method for a kind of laser-induced fusion called fast ignition.

Read more ....

The Smallest Laser Ever Made

Tiny laser: This simulation shows the intensity of light around a new type of laser, called a spaser, when operating in a plasmon-producing mode. The concentration of plasmons is most intense at the gold sphere that makes up its core. The inner black circle indicates the position of the sphere, which is coated with a dye-embedded silica shell, marked by the outer black line. Credit: Nature

From Technology Review:

Surface-plasmon lasers could enable a new generation of computers based on nanophotonics.

Researchers have demonstrated the smallest laser ever, consisting of a nanoparticle just 44 nanometers across. The device is dubbed a "spaser" because it generates a form of radiation called surface plasmons. The technique allows light to be confined in very small spaces, and some physicists believe that spasers could form the basis of future optical computers just as transistors are the basis of today's electronics.

Read more ....