Theoretical laser put to the test by UH professor
A UH chemistry professor will see his theoretical research on organic semiconductors put to the test in an experiment that will fire photons into a semiconductor sandwiched between two mirrors.
If his theory holds true, the prototype will emit a powerful laser that may eventually carry sensitive information.
Professor Eric Bittner, a 2012-13 Fulbright fellow, will use the funding from the fellowship to observe the experiments with physics professor Carlos Silva at the Universite de Montreal and to lecture on his findings there.
“Carlos’ group is really at the cutting edge of the experiments. Nobody has done this experiment yet,” Bittner said. “He has sunk a lot of his energy and resources into doing this.”
If Bittner’s predictions are correct, this process could produce a focused, bright burst of radiation — a laser — in a specific direction. This potential result has sparked the interests of many security companies.
“Depending upon how you prepare the state, you can encode information in the light that is being emitte
d. You can use it for optical communication, most importantly for quantum cryptography,” Bittner said.
“If you have an intermediate receiver that destroys the quantum information, then you’ll know that you’ve been tapped. So the security agencies are really interested in this kind of stuff. It’s an unbreakable encryption, so you know if somebody has intercepted your signal.”
Unfortunately, this sort of technology is at least a decade away, but for now, Bittner’s grant will cover his living expenses for four-to-five months while in Montreal.
“Right now, we are looking at it as a way to study a real fundamental, atomic many-bodied physics in a setting that’s really controllable and also in a dimensionality that’s usually not studied in the atomic setting,” Bittner said.
By sandwiching organic semiconductor material between two reflecting mirrors, they will set up a strong coupling situation — a condition that creates a quasiparticle called a polariton and causes a phase transition.
This transition has not been observed in the organic materials they are studying. It produces the condensate being analyzed, which is a superfluid called a Bose-Einstein condensate.
“Imagine that you have a room full of people trying to dance. If you have just one or two people in a room, it’s easy to do whatever you want to do,” Bittner said. “But as you start packing more and more people into that same volume, everybody’s got to start doing the same thing in order to add one more person.”
The Bose-Einstein condensate is unique because it’s two-dimensional, which is usually forbidden. It’s also from a non-equilibrium system, meaning it must be continuously driven for it to undergo the transition,” Bittner said.
“We’ve made some predictions, setting up some parameters for where this effect could occur, and Silva is going to try to observe it,” Bittner said. “If it happens, it’s a pretty cool effect.”