Breakthrough in Light Sources:

Technion Researchers Discover and Develop

New Light Sources Emitting Photon Pairs

Three patents registered around this discovery and commercialization is taking place; it can be used in new devices for detection of cancer, constructing advanced lasers and precision measurements, as well as building block in quantum communications and computers

Technion researchers have discovered and developed novel light sources that emit photon pairs - sources that will aid in detection and identification of cancer; will be used to construct advanced lasers and to generate very short optical pulses, as well as for building quantum communication and computers. The Technion has registered three patents on this discovery and the technology is under commercialization.

“Regular light sources emit light made up of photons,” explains Prof. Meir Orenstein of the Technion’s Faculty of Electrical Engineering. “Our group discovered and developed new light sources that emit photon pairs rather than a stream of photons.” The discovery was published in the scientific journal “Nature Photonics” and is arousing great interest in the scientific community. The possibility of photon pair emission has been known for decades, but until now, no one had succeeded in measuring the phenomenon in practical materials (it had been measured only in atoms in gas phase).

The Technion researchers decided to try and measure it in solid state and succeeded in doing this – specifically in semiconductors. After they had demonstrated the physical phenomenon – for the first time in a solid state – they built a special LED device that emits photon pairs rather than a photon stream. This scientific achievement was attained by Prof. Orenstein and doctoral students Alex Hayat and Pavel Ginzburg, and later joined by Amir Nevet.

“Light sources emitting photon pairs have different characteristics from those of conventional light sources,” explains Prof. Orenstein. “Firstly, our device simultaneously emits a very broad range of colors, especially in the entire infrared range – something that is ideal for sensing – for example in identifying biological materials or contaminants. In order to achive it, you have to illuminate these materials in a very broad range of colors. Regular LED emits light in a specific color and not in many colors. An additional characteristic of our device is emission of very short pulses in time, a feature that assists in precise measurement of time and space. In addition, the fact that the two photon of each pair are emitted at the same time creates a quantum connection between them – which is essential for building quantum computers and communications. And all of these are being implemented in a very small device that operates at room temperature with potential very low-cost”

Recently, the Technion researchers reported on two more breakthroughs in this field. In an article in the scientific journal “Physical Review Letters,” they reported that for the first time, an optical amplifier of photon pairs was built in solid state. In the optical amplifier, the amount of light emitted from the device is greater than the amount of light entering into it and this provides the basis upon which a laser of photon pairs will be built. The Technion researchers also succeeded in integrating photon pairs emission into nanometric structures, thus increasing the emission power by one thousand times. This achievement was published in the scientific journal “Nano Letters.”