Comprehensive coverage

Technion researchers discovered and developed new light sources that emit pairs of photons

Three patents were registered around the discovery and the technology is in advanced commercialization processes; It will be possible to use the new devices to detect cancer, to create advanced lasers and precise measurements, as well as to build communications and quantum computers

Photons emitted from a coherent laser beam in a US military experiment. Photo: from Wikipedia
Photons emitted from a coherent laser beam in a US military experiment. Photo: from Wikipedia

Technion researchers have discovered and developed new light sources that emit pairs of photons, something that will help identify types of cancer, create advanced lasers and extremely short optical pulses, as well as build communications and quantum computers. The Technion registered three patents for the discovery and is in the process of commercializing the technology.

"Light sources emit light composed of photons," explains Professor Meir Orenstein from the Faculty of Electrical Engineering at the Technion. "Our group discovered and developed new light sources that emit pairs of photons and not a stream of photons." The discovery was published in the scientific journal Nature Photonics and aroused great interest in the scientific world. The physical possibility of the emission of photon pairs has been known for decades, but until now no one has been able to measure the phenomenon in applicable materials (it has only been measured in atoms in a gaseous state). The Technion researchers decided to try to measure it in the solid state as well and indeed succeeded in doing so in materials that are semiconductors. After they demonstrated the physical phenomenon - as mentioned for the first time in the solid state, they built a special LED device, which emits pairs of photons rather than a stream of photons. This scientific achievement was achieved by Professor Orenstein and his doctoral students - Alex Hayat and Pavel Ginzburg, and later also Amir Nebat.

"Light sources that emit photon pairs have different properties from those of the light sources known today," explains Professor Orenstein. "First, our device simultaneously emits a very wide range of colors, and especially in the entire infrared range - something that is ideal for sensing - for example for detecting pollutants or biological substances. To discover them, you have to shine a light on them in a very wide range of colors. The normal LED emits light in a certain color and not in many colors. Another feature of our device is emission in very short pulses in time, which helps accurate measurements of times and distances. Also, the fact that each pair of photons is emitted at the same time creates a quantum connection between these photons, which is essential for building quantum computers and communication. All of these are applied in a very small component that operates at room temperature and has a very low cost."

Technion researchers recently reported two more breakthroughs in this field. In an article in the scientific journal Physical Review Letters, they reported the first time an optical amplifier of photon pairs was built in a solid state. In an optical amplifier, the amount of light leaving the device is greater than the amount of light entering it, and this is the basic cornerstone on which a laser of photon pairs can be built. The Technion researchers were also able to integrate the emission of photon pairs within nanometer structures, thereby increasing the intensity of the emission a thousand times. This achievement was published in the scientific journal Nano Letters.

19 תגובות

  1. Response 16 can be ignored, since it is childish and stupid, and therefore not worthy of consideration.

  2. Does that mean that your (the scientists') 'Torah' is also based on nonsense?

  3. Anonymous user:

    I can only assume that Zvi meant "you will never measure" when he wrote "you will never measure".

  4. deer

    First of all thanks for the explanation.
    I have not yet tried to calculate the data you wrote down, but it is still not clear to me how you arrived at the result of 2.5
    It is clear that the equation E=hf does not give the value 2.5. That is, calculations of additional data (which you mentioned) need to be made, and indeed I was hoping that you would write down the entire equation as a result of which the data 'light intensity' is equal to the value '2.5'.

  5. A small numerical calculation:
    Light has a visible wavelength between 4000 and 7000 angstroms (angstroms = 10-^10 m).
    That is 5-^10*4-7 cm.
    The speed of light is 10^10*3 cm per second and thus the frequency (speed divided by wavelength) is approximately 15^10 Hz. Multiply by Planck's constant (27-^10*6.626) and we get roughly:
    11-^10 arg.

    Calculate how many photons hit a square cm per second on the Earth's surface as a result of solar radiation:
    Solar radiation is 33^10*3.8 erg per second.
    The distance of Kadhaa from the sun is 13^10*1.5 cm, which means that the area of ​​the mantle at the distance where Kadhaa is located is about 27^10*2.83, which means something like 6^10*1.35 erg per second per square centimeter - that is:
    Every second, as many as 17^10 photons from the sun's radiation hit a square centimeter of Earth's surface.

    This is only an order of magnitude - when the main approximation was the assumption that all photons from the sun are the same color - in fact the result should be higher because I assumed a relatively energetic photon - if so it gives some kind of understanding.

  6. Yes:

    The amount of angi in a single photon satisfies E=hf where f is the frequency of the photon and h is Planck's constant.

  7. deer

    "..that the intensity of a measured light beam will always be a whole number times the intensity of a single photon (if the intensity of each photon is 1 - the intensity of light will always be measured as 2.5)."
    Please can you translate this into a mathematical equation?

  8. 1. To the point (response 6): Your comment is arrogant, and out of place. See response number 7, by Zvi.
    2. Lezvi (response 7): Well done for the simple and exhaustive explanation!

  9. Raphael,

    In general, light is emitted in the form of particles called photons - among other things, one of the meanings is that the intensity of a measured light beam will always be a whole number times the intensity of a single photon (if the intensity of each photon is 1 - the intensity of light will always be measured as 2.5).
    The intensity of a single photon depends on the frequency - and for us, on the "color" of the photon.

    Why don't we know this from everyday life?
    For the most part, the number of photons to which we are exposed on a daily basis is enormous - and therefore we do not notice this discretization - just as on a daily basis we do not feel that matter is made of atoms because we cannot see with our eyes a small number of atoms.

    In laboratory experiments it is possible to obtain relatively low numbers of photons - but for the most part (and I am telling you this based on this article and not based on any prior knowledge) the way to produce them was from a gas (I am guessing that by applying an electric field to a gas and causing atomic excitations or things like This is not so relevant at this point.
    Now they have somehow managed to make the solid emit only two photons and this is probably significant for all sorts of technological reasons.

    Finally, a number of practical options were offered for things in which the disclosure might be useful:
    Medical uses (remote sensing) - probably because the light emitted in this way is much more controlled and thus it is possible to receive much finer information from it.
    Quantum computers - this subject is complicated, but in general the idea is that when you go down to the resolutions of individual photons (or any small particles) - the world does not behave as we know it, among other things the particles are not in defined states in terms of all their physical parameters (they do not have, let's say, a defined momentum and a defined location), it is possible to take advantage of these uncertainties for computational needs and the theoretical predictors predict that with this, it will be possible to build computers that are substantially and not only qualitatively stronger than the computers that exist today. The problem is that there is a technological difficulty in creating such computers and the authors of the study predict that their research can perhaps help solve these technological difficulties.

  10. Wait wait uncle it will take time for it to be applicable.

    And most likely as a technician nothing will change tickets will be tickets.

  11. Printed circuits in which electronic components communicate using light and not electricity, an optical path and not a copper path? And will there be an impact on the repair or installation of hardware and equipment at the technician level or is it more at the research and development level?

Leave a Reply

Email will not be published. Required fields are marked *

This site uses Akismat to prevent spam messages. Click here to learn how your response data is processed.