Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


“Controlling light with light”: Martini and post-doctoral researcher Murawski


Near-infrared laser transfers data to mid-infrared laser’s beam

“Interband transitions controlling intersubband transitions” is the technical description for what has been achieved in an optics lab in Stevens Institute of Technology’s Physics Department. Robert K. Murawski, a post-doctoral research assistant working under the direction of Professor Rainer Martini , has a simpler way to describe it: “Controlling light with light.”

Regardless of styling, the concept is not a new one, but its first demonstration in a laboratory opens new horizons in telecommunications, with implications for the secure, all-optical transmission of voice and data. Martini credits Murawski for having made the initial measurements proving that the principle is physically possible in a controlled environment.

“Basically,” explains Murawski, “we use a conventional kind of laser beam to ‘switch’ another, more advanced kind of laser beam – and it all happens in mid air.

“One laser beam is mid-infrared,” he says. “We illuminate it directly with a fiber-optic laser diode, which is near-infrared – and if that light has a message on it, then the mid-infrared will have a message on it once it passes through. You can use the fact, then, that the mid-infrared can transmit to the atmosphere to do things like free-space communications without fiber optics.”

“All current wavelength for optical communication is near-infrared, which is highly unreliable in a free-space environment,” explains Martini, a veteran of Lucent Technologies and the director of the Ultrafast Laser Spectroscopy & Communication Laboratory at Stevens. “The mid-infrared, which is generated by what is called a ‘quantum cascade laser’ or QCL, overcomes many of those limitations in traveling through free space. Plus, because it is ultra-focused, the QCL beam is a much more secure means by which to communicate than by broadcasting or other kinds of telephony.”

Another beauty of the near-infrared/QCL assembly, says Martini, is that “your switches act on two different wavelengths, and they are clearly separate and distinct. The two wavelengths can be handled and processed in independence. There’s no overlap, because we have the whole system clearly detangled.”

Martini and Murawski are quite confident that their achievement is unique.

“In the quantum cascade physics knowledge-base,” says Murawski, “there’s little if any work that’s been done like this. Interband transitions are really not talked about.”

Murawski believes that in the field of advanced quantum cascade lasers, in the physics area, Martini’s lab has developed a more complete picture of those particular dynamics “than anyone else currently working around the world.”

“Robert’s thesis,” says Martini, “is really the first complete theoretical discussion about the immense potential of modulating QCL at high speeds. His thesis sets the limits for how fast that laser can be.”

Murawski, who defended his dissertation in early May, says that the Martini lab has also figured out “how to preserve the integrity of the hardware package. You don’t want the QCL damaged or melting down while it’s in action.”

Martini is also proud that his lab houses a unique quantum cascade laser.

“It managed the fastest-recorded QCL modulation in the world. Everybody talked about it,” he says, “but we achieved it.”

Martini says that the controlling of light with light opens up a world of futuristic applications which – because they are imaginable – may at some point be possible.

“The question is,” he says, “What is happening in the laser beam when the interband transition takes place? The QCL is unique. One of the big issues is, you send current through it, and that current drops down making the laser transition. So when the first electron drops down, it tells the other electrons to go with it. So there’s a kind of ‘intelligence among the electrons.’ If we can reach in and manipulate that action, who knows what we can engineer using the properties of the laser beam?”

Established in 1870, Stevens offers baccalaureate, masters and doctoral degrees in engineering, science, computer science, management and technology management, as well as a baccalaureate in the humanities and liberal arts, and in business and technology. The university has enrollments of approximately 1,740 undergraduates and 2,600 graduate students. Additional information may be obtained from its web page at

Patrick Berzinski | Stevens Institute of Technology
Further information:

More articles from Communications Media:

nachricht Product placement: Only brands placed very prominently benefit from 3D technology
07.07.2016 | Alpen-Adria-Universität Klagenfurt

nachricht NASA Goddard network maintains communications from space to ground
02.03.2016 | NASA/Goddard Space Flight Center

All articles from Communications Media >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

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...

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

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>