the Quantum Cascade Laser, by EVANSTON, Ill., July 24 (UPI) -- U.S

Scientists have designed a new type of semiconductor-based laser called the Quantum Cascade Laser, with greatly increased output power.

Researchers at the Center for Quantum Devices at North-western University, led by Professor Manijeh Razeghi, have also increased the laser's wall-plug efficiency-the ability to change electrical power into light.

The scientists have demonstrated individual lasers, 300 of which can easily fit on a penny, emitting wavelengths of 4.5 microns, capable of producing more than 700 mill watts of continuous output power at room temperature and more than one watt of output power at lower temperatures.
The lasers are also extremely efficient in converting electricity to light, having a 10 percent wall-plug efficiency at room temperature and more than 18 percent wall-plug efficiency at lower temperatures. That represents a factor of two increase in laser performance, which is far superior to any competing laser technology at this wavelength.
The research has been submitted for publication.

Lasers, as they exist now, are concentrated streams of light particles, or photons.
The discovery by Florence University, Italy, 6 July (UPI), researchers will produce lasers of atoms, rather than photons, which was previously impossible because scientists could not find a way to stop atoms from colliding into one another.
An atomic laser is eagerly awaited in the field of micro-electronics, said leading scientist Massimo Inguscio.
Inguscio's team used potassium isotopes to build an "atomic condensate" squeezed into a harmonious whole by a magnetic field, similar to a theoretical model envisioned by Einstein and his colleague Satyendra Nath Bose
"In this way the interaction of atoms is virtually nonexistent".

YOKOHAMA, Japan, 21 June  (UPI) -- Japanese scientists have developed a highly efficient, room-temperature nanolaser that produces stable, continuous streams of near-infrared laser light.
Yokohama National University researcher Toshihiko Baba and colleagues said the overall device has a width of several microns, while the part of the device that actually produces laser light has dimensions at the nanometer scale in all directions.
The laser uses only one microwatt of power, achieving one of the smallest operating powers ever reported.
The researchers said their nanolaser design should be useful in miniaturized circuits containing optical devices.
The research appears in the journal Optics Express.

Reference:
http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20070724-10515100-bc-us-laser.xml

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