#twisted light

[aconstantstateofphotography]

old light

[wayti-blog]

Twisted light gives electrons a spinning kick: Researchers develop a novel way to control quantum interactions

It's hard to tell when you're catching some rays at the beach, but light packs a punch. Not only does a beam of light carry energy, it can a

"It's hard to tell when you're catching some rays at the beach, but light packs a punch. Not only does a beam of light carry energy, it can also carry momentum. This includes linear momentum, which is what makes a speeding train hard to stop, and orbital angular momentum, which is what the Earth carries as it revolves around the sun.

In a new paper, scientists seeking better methods for controlling the quantum interactions between light and matter have demonstrated a novel way to use light to give electrons a spinning kick. They reported the results of their experiment, which shows that a light beam can reliably transfer orbital angular momentum to itinerant electrons in graphene, on Nov. 26, 2024, in the journal Nature Photonics.

Having tight control over the way that light and matter interact is an essential requirement for applications like quantum computing or quantum sensing. In particular, scientists have been interested in coaxing electrons to respond to some of the more exotic shapes that light beams can assume."

continue reading

[unluckyservice4]

Can we get Monaca head cannons?

((Monica...my problem child...

-Monica is also like a cat with cuddles, but she's also more possessive. Soon as that girl gets love she is ATTACHED and you are hers.

-Junko has been keeping her and Nagito mostly separate and telling her things so she isn't as attached to him. Things like, because he hates Junko and doesn't hide it he's their enemy in a way. Because he hates despair. And Monica is on the side of Despair.

-Junko and Monica met at the elementary school. Monica was walking briefly, and Junko was very impressed by her lies.

-She does care about Servant, deep down. But it's mostly an unconscious thing. (she's so starved for parental affection she doesn't want another dad but she still needs...wants, wants, wants)

-She's the only one who will figure out that Nagito's dying on her own. She also thinks his luck is stupid and wants no part of it.

-Everything she knows she learned from her father, her brother, and Junko and Nagito. She is the sum of their worst parts.

-Nagito taught her (and the rest of the warriors) everything they know about explosives.

[unluckyservice4]

only drawn kotoko before and it was like once so 😔😔

here you go 2/5 warriors of cope

:O They look so good....my kids...

[infinityworldnews]

Japanese Scientists Conceive Twisted Light Could Explain Birth Of The Universe

Japanese Scientists Conceive #TwistedLight Could Explain Birth Of The #Universe

A group of Japanese researchers may have discovered another methodology towards physics in the wake of contemplating the curved light from space. This light is diverse because it showed up after the massive explosion. The examination was distributed in November 2020 by the Journal Physical Review Letters. Their analysis may offer another hope to characterize physics and how more confounded…

View On WordPress

[futuristech-info]

Twisted light could "revolutionize future data transmission" - New record shows its promise

[scifigeneration]

New approach uses 'twisted light' to increase efficiency of quantum cryptography systems

Researchers have developed a way to transfer 2.05 bits per photon by using 'twisted light.' This remarkable achievement is possible because the researchers used the orbital angular momentum of the photons to encode information, rather than the more commonly used polarization of light. The new approach doubles the 1 bit per photon that is possible with current systems that rely on light polarization and could help increase the efficiency of quantum cryptography systems.

Quantum cryptography promises more secure communications. The first step in such systems is quantum key distribution (QKD), to ensure that both the sender and receiver -- usually referred to as Alice and Bob -- are communicating in such a way that only they know what is being sent. They are the only ones who hold the "key" to the messages, and the systems are set up in such a way that the presence of any eavesdropper would be identified.

In the paper, published in New Journal of Physics Today, Mohammad Mir Hosseini and his colleagues describe a proof-of-principle experiment that shows that using OAM to encode information rather than polarization opens up the possibility of high-dimensional QKD. Mirhosseini, a Ph.D. student in Robert W. Boyd's group at the University of Rochester's Institute of Optics, explains that they were able to encode a seven dimensional "alphabet" -- that is, seven letters or symbols -- using both the orbital angular momentum (OAM) of the photons and their angular position (ANG). These two properties of the photons form what physicists refer to as mutually unbiased bases, a requirement for QKD. Using mutually unbiased bases, the correct answer is revealed only if Alice encodes the information using a particular basis and Bob measures in that same basis.

In QKD, once they have generated a long, shared key, Alice and Bob publicly announce the basis (or "alphabet") they have used for each symbol in the key. They then compare what alphabet was used for sending and which one for receiving. They only keep the part of the key in which they have used the same "alphabet." The letters they keep produce a secure key, which they can use to encrypt messages and transmit these with regular encryption without the need for quantum cryptography.

If for any reason their communication is intercepted, because of a fundamental property of quantum mechanics, there will be discrepancies between Alice and Bob's keys. To check for this, Alice and Bob sacrifice a short part of their key. They share this publicly and identify any discrepancies. This lets them know whether their connection is secure and, if not, they will stop the communication.

The researchers showed that using their system they were able to generate and detect information at a rate of 4kHz and with 93% accuracy. A long term goal of the research is to realize secure communications at GHz transmission rates, which is desirable for telecommunication applications.

"Our experiment shows that it is possible to use "twisted light" for QKD and that it doubles the capacity compared to using polarization," said Mirhosseini. "Unlike with polarization, where it is impossible to encode more than one bit per photon, "twisted light" could make it possible to encode several bits, and every extra bit of information encoded in a photon means fewer photons to generate and measure."

In a previous experiment using a strong laser beam instead of single photons, Boyd's team were able to measure up to 25 modes of OAM and ANG. This is equivalent to having 25 letters available in your "alphabet" rather than 7. This shows the potential for a system like the one described in the new paper to have the capacity to transmit and measure 4.17 bits per photon using more sophisticated equipment.

Mirhosseini acknowledges that the real-world challenges are not straightforward to overcome but when it comes to QKD, he is excited about the possibilities their system opens up.

[semiconductivity-blog]

Vienna demonstration shows that the technology can boost data capacity of laser beams over long distances.

Physicists and engineers have developed an array of tricks to increase the amount of data that can be crammed into optical or radio waves: chopping a broad wavelength band into several narrower channels, for example, or sending distinct data streams along circularly polarized waves that rotate either clockwise or anticlockwise.

But 'twisted light' potentially offers a much greater capacity boost. Light waves can carry orbital angular momentum (OAM) — when the fluctuations of the light's electromagnetic waves are staggered along different parallel light rays. This is analogous to a row of soldiers marching in lockstep but moving their arms at different times. Adding orbital angular momentum to a laser beam can produce a theoretically infinite range of corkscrew patterns, known as modes. Crucially, different OAM modes can travel long distances without interfering with each other, even if they are carried in overlapping light beams with identical wavelengths. 

A Vienna research team used green laser light with 16 different OAM modes to send data from the top of a radar tower to a small detector across the city, successfully transmitting small black-and-white pictures of Wolfgang-Amadeus Mozart and the physicists Ludwig Boltzmann and Erwin Schrödinger — all of them Austrians. Each OAM mode was assigned to a different shade of grey, from black to white. A quick burst of one mode indicated a dark-grey pixel; a different mode signalled that the next pixel was white; and so on. Pattern-recognition software helped to identify each mode as it arrived, achieving an error rate of just 1.7%. The modes switched four times per second, and the images built up pixel by pixel. As data-transmission rates go, it is not much better than a human beeping in Morse code. But the experiment showed that OAM modes can survive for much longer trips through the atmosphere than expected, and raises hopes that the same success would be seen if the modes were used as 

Visible laser light should not suffer so much from this spreading, potentially allowing OAM modes to travel for dozens of kilometres or more. Zeilinger’s team notes that the amount of atmosphere between the ground and space is roughly equivalent to about 6 kilometres of sea-level atmosphere, suggesting that OAM modes might make it all the way to space without being mixed up in transit.