World’s Smallest Semiconductor Laser Created by University of Texas Scientists

July 26, 2012

AUSTIN, Texas — Physicists at The University of Texas at Austin, in collaboration with colleagues in Taiwan and China, have developed the world’s smallest semiconductor laser, a breakthrough for emerging photonic technology with applications from computing to medicine.

The scientists report their efforts in this week’s Science.

Miniaturization of semiconductor lasers is key for the development of faster, smaller and lower energy photon-based technologies, such as ultrafast computer chips; highly sensitive biosensors for detecting, treating and studying disease; and next-generation communication technologies.

Nanolaser illustration

Illustration of the nanoscale semiconductor structure used for demonstrating the ultralow-threshold nanolaser. A single nanorod is placed on a thin silver film (28 nm thick). The resonant electromagnetic field is concentrated at the 5-nm-thick silicon dioxide gap layer sandwiched by the semiconductor nanorod and the atomically smooth silver film.

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.

“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.”

In the current paper, Shih and his colleagues report the first operation of a continuous-wave, low-threshold laser below the 3-D diffraction limit. When fired, the nanolaser 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 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.

UT Physics graduate student Charlotte Sanders

Physics graduate student Charlotte Sanders' research with Professor Ken Shih helped develop the world's smallest nanolaser. She stands here with a molecular beam epitaxy (MBE) machine that she designed and built in collaboration with the Department of Physics Machine Shop and with assistance from co-author Dr. Jisun Kim. The machine is used to create a smooth silver thin film critical to the function of the laser. Photo by Alex Wang.

It’s a material that the Shih lab has been perfecting for more than 15 years. That “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 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 Taiwan and a former doctoral student of Shih’s.

Shih and Gwo’s colleagues include Gennady Shvets, professor of physics at The University of Texas at Austin, and Lih-Juann Chen, professor at National Tsing Hua University.

For more information, contact: Lee Clippard, Lady Bird Johnson Wildflower Center, 512-232-0104; Dr. Ken Shih, professor of physics, shih@physics.utexas.edu

7 Comments to "World’s Smallest Semiconductor Laser Created by University of Texas Scientists"

1.  sunny said on July 29, 2012

this smallest semiconductors may bring biggest revolution in nano technology

2.  jesse said on July 30, 2012

what are the advantages & disadvantages and also the applications of the smalest semiconductor laser

3.  Theo said on July 31, 2012

Pros - much less energy required, light travels nearly half an order of magnitude faster than electricity, the bandwidth is (much) higher without all those capacitive losses, it's really cool in all senses of the term.
Cons - it's tough to implement.

4.  Victor Genty said on Aug. 2, 2012

Charlotte you rule!

5.  Doug Davis said on Aug. 3, 2012

They physics department at the University of Texas is top notch my friends. I am delighted to be apart of this wonderful community.

6.  jeramy said on Aug. 13, 2012

where can i get one /?

7.  marcelo castillo said on Aug. 14, 2012

i want to know, if this like transistor chips semi conductor with three grid wire on it?