Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


High-Speed Signal Mixer Demonstrates Capabilities Of Transistor Laser

Scientists at the University of Illinois have successfully demonstrated a microwave signal mixer made from a tunnel-junction transistor laser.

Development of the device brings researchers a big step closer to higher speed electronics and higher performance electrical and optical integrated circuits.

The mixing device accepts two electrical inputs and produces an optical signal that was measured at frequencies of up to 22.7 gigahertz. The frequency range was limited by the bandwidth of the detector employed in the measurements, not by the transistor device.“

"In addition to the usual current-modulation capability, the tunnel junction provides an enhanced means for voltage-controlled modulation of the photon output of the transistor laser,” said Nick Holonyak Jr., a John Bardeen Chair Professor of Electrical and Computer Engineering and Physics at the U. of I. “This offers new capabilities and a much greater sensitivity for unique signal-mixing and signal-processing applications.”

To make the device, the researchers first placed a quantum well inside the base region of a transistor laser. Then they created a tunnel junction within the collector region. They describe the fabrication and operation of the mixing device in the March 13 issue of the journal Applied Physics Letters.

“Within the transistor laser, the tunneling process occurs predominantly through a process called photon-assisted absorption,” said Milton Feng, the Holonyak Chair Professor of Electrical and Computer Engineering.

The tunneling process begins in the quantum well, where electrons and holes combine and generate photons, Feng said. Those photons are then reabsorbed to create new pairs of electrons and holes used for voltage modulation.

“The tunnel junction makes it possible to annihilate an electron in the quantum well, and then tunnel an electron out to the collector by the tunnel contact,” Feng said.

The transistor output is sensitive to third-terminal voltage control because of the electrons tunneling from the base to the collector, which also creates an efficient supply of holes to the quantum well for recombination.

“This is a new type of transistor,” said Holonyak, who also is a professor in the university’s Center for Advanced Study, one of the highest forms of campus recognition. “We are using the photon internally to modify the electrical operation and make the transistor itself a different device with additional properties.”

High-speed signal mixing, for example, is made possible by the nonlinear coupling of the internal optical field to the base electron-hole recombination, minority carrier emitter-to-collector transport, and the base-to-collector electron tunneling at the collector junction, the researchers report.

The sensitivity of the tunnel-junction transistor laser to voltage control enables the device to be directly modulated by both current and voltage. This flexibility facilitates the design of new nonlinear signal processing devices for improved optical power output.

“The metamorphosis of the transistor is not yet complete,” Holonyak said. “We’re still working on it, and the transistor is still changing.”

Co-authors of the paper are graduate research assistant and lead author Han Wui Then, graduate student Hsin-Yu Wu and senior research scientist Gabriel Walter.

James E. Kloeppel | University of Illinois
Further information:

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>