Physicists at Texas Create the World’s Smallest Semiconductor Laser

The world's smallest semiconductor laser that is a breakthrough for emerging photonic technology with applications from computing to medicine is being created by the physicists at The University of Texas at Austin in collaboration with colleagues in Taiwan and China.

"We have developed a nanolaser device that operates well below the 3-D diffraction limit," said Chih-Kang "Ken" Shih, professor of physics at The University of Texas at Austin. "We believe our research could have a large impact on nanoscale technologies."

Shih and his colleagues reported in the week's Science, the first operation of a continuous wave, low threshold laser below the 3-D diffraction limit. When fired, the nanolaser emits a green light. And this laser is too small to be visible to the naked eye.

The physicists constructed this device with gallium nitride nanorod that is partially filled with indium gallium nitride. Both alloys are semiconductors used commonly in LEDs. The nanorod 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.

For nearly 15 years Shih lab has been working towards the perfection of the material. Because according to the physicists "atomic smoothness" is the 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 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.

Shangjr Gwo, professor at National Tsing Hua University in Taiwain and a former doctoral student of Shih's concluded saying, "Size mismatches between electronics and photonics have been a huge barrier to realize on-chip optical communications and computing systems."