Physicists manufacture world's smallest semiconductor Laser.

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Smallest Laser production principle.

  A collaboration between Physicists at the University of Texas at Austin and colleagues in China and Taiwan has led to the development of the worlds smallest Laser. This is according to this week's Science report  on their work. Chih-Kang "Ken" Shih, professor of physics at The University of Texas at Austin says that they've developed a nanolaser device that operates well below the 3-D diffraction limit which would have a large impact on nano-scale technologies. The miniaturization of semiconductor lasers is key for the development of faster, smaller and lower energy photon-based technologies, such as ultra-fast computer chips; highly sensitive bio-sensors for detecting, treating and studying disease; and next-generation communication technologies.
 Such photonic devices could use nanolasers to generate optical signals and transmit information, and have the potential to replace electronic circuits. But the size and performance of photonic devices have been restricted by what's known as the three-dimensional optical diffraction limit.

 
In their Science paper, the developers report that the first operation of a continuous-wave, low-threshold laser below the 3-D diffraction limit. When fired, the nano-laser emits a green light. The laser is too small to be visible to the naked eye.
 The device is constructed of a gallium nitride nanorod that is partially filled with indium gallium nitride. Both alloys are semiconductors used commonly in LEDs. The nano-rod is placed on top of a thin insulating layer of silicon that in turn covers a layer of silver film that is smooth at the atomic level.This material has been undergoing perfection in professor Chih-Kang Shih's lab for over 15 years. Its "atomic smoothness" is key to building photonic devices that don't scatter and lose plasmons, which are waves of electrons that can be used to move large amounts of data.
 "Atomically smooth plasmonic structures are highly desirable building blocks for applications with low loss of data," said professor Shih.
 Nanolasers such as this could provide for the development of chips where all processes are contained on the chip, so-called "on-chip" communication systems. This would prevent heat gains and information loss typically associated with electronic devices that pass data between multiple chips.
"Size mismatches between electronics and photonics have been a huge barrier to realize on-chip optical communications and computing systems," said Shangjr Gwo, professor at National Tsing Hua University in Taiwain and a former doctoral student of Shih's.