Hexbyte Glen Cove Stabilized blue phase crystals could lead to new optical technologies

Hexbyte Glen Cove

Stabilized blue phase liquid crystals, developed by Prof. Juan de Pablo and his team, can reflect blue and green light, and can be switched on and off incredibly quickly, opening the door to faster response times in optical technologies. Credit: Wikimedia Commons

Liquid crystals already provide the basis for successful technologies like LCD displays, and researchers continue to create specific kinds of liquid crystals for even better optical devices and applications.

Juan de Pablo, Liew Family Professor of Molecular Engineering at the Pritzker School of Molecular Engineering (PME) at the University of Chicago, and his team have now found a way to create and stabilize so-called “blue phase liquid crystals,” which have the properties of both liquids and crystals, and can in some cases reflect better than ordinary liquid crystals.

The results, published in ACS Nano, could lead to new optical technologies with better response times.

A new method for stabilizing blue phase crystals

Thanks to their uniform molecular orientation, liquid crystals are already the basis for many display technologies, including those in digital displays for computers and televisions. In this research, de Pablo and his team were interested in chiral liquid crystals, which have a certain asymmetrical “handedness”—like right-handedness or left-handedness—that allows them to exhibit a wider and more interesting range of optical behaviors.

Importantly, these crystals can form blue phase crystals, which because of their unique structure, can reflect blue and green light, and can be switched on and off incredibly quickly. But these crystals only exist in a small range of temperatures and are inherently unstable: Heating them up even one degree can destroy their properties. That has limited their use in technologies.

Through simulation and experiments, the team was able to stabilize the blue phase crystals through the formation of so-called double emulsions. They used a small core droplet of a water-based solution surrounded by an outer droplet of an oily chiral , thereby creating a “core and shell” structure. That structure was itself suspended in another water-based liquid, unmixable with the liquid crystal. Over the appropriate range of temperatures, they were able to trap the chiral liquid crystal in the shell in a “blue phase” state. They then formed a polymer network within the shell, which stabilized the blue crystal without destroying its properties.

Creating perfect crystals

The team then showed that they could change the temperature of the blue phase crystal by 30 degrees without destroying it. Not only that, the process formed perfect, uniform blue phase crystals, which allowed the researchers to better predict and control their behavior.

“Now that we understand these materials and can control them, we can take advantage of their unique optical properties,” de Pablo said. “The next step is deploying them in devices and to demonstrate their usefulness.”

Potential applications include display technologies that could be turned on and off with very small changes in size, temperature, or exposure to light, or sensors that can detect radiation within a certain wavelength.



More information:
Monirosadat Sadati et al, Control of Monodomain Polymer-Stabilized Cuboidal Nanocrystals of Chiral Nematics by Confinement, ACS Nano (2021). DOI: 10.1021/acsnano.1c04231

Citation:
Stabilized blue phase crystals could lead to new optical technologies (2021, November 2)
retrieved 2 November 2021
from https://phys.org/news/2021-11-stabilized-blue-phase-crystals-optical.html

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Hexbyte Glen Cove Optical chip protects quantum technology from errors thumbnail

Hexbyte Glen Cove Optical chip protects quantum technology from errors

Hexbyte Glen Cove

Credit: CC0 Public Domain

In today’s digital infrastructure, the data-bits we use to send and process information can either be 0 or 1. Being able to correct possible errors that may occur in computations using these bits is a vital part of information processing and communication systems. But a quantum computer uses quantum bits, which can be a kind of mixture of 0 and 1, known as quantum super-position. This mixture is vital to their power—but it makes error correction far more complicated.

Researchers from DTU Fotonik have co-created the largest and most complex photonic processor to date—on a microchip. It uses single particles of light as its quantum bits, and demonstrates a variety of protocols with photonic for the first time.

“We made a new optical microchip that processes quantum information in such a way that it can protect itself from errors using entanglement. We used a novel design to implement error correction schemes, and verified that they work effectively on our photonic platform,” says Jeremy Adcock, postdoc at DTU Fotonik and co-author of the Nature Physics paper.

This research is important because error correction is key to developing large-scale quantum computers, which will unlock new algorithms for e.g. large-scale chemical simulations and faster machine learning.

One key application could be drug discovery. Today’s computers cannot simulate large molecules and their interactions, for example when you introduce a drug molecule to the human body. In today’s computers, the size of classical computation grows exponentially with the size of the molecules involved. But for future quantum computers, more are known, which do not blow up in computational cost.

This is just one of the problems that the quantum technology of the future promises to solve, by being able to process information beyond the fundamental limits of traditional computers. But to reach this goal, we have to go small:

“Chip-scale devices are an important step forward if quantum technology is going to be scaled up to show an advantage over classical computers. These systems will require millions of high-performance components operating at the fastest possible speeds, something that is only achieved with microchips and integrated circuits, which are made possible by the ultra-advanced semiconductor manufacturing industry,” says co-author Yunhong Ding, senior researcher at DTU Fotonik.

To realize quantum technology that goes beyond today’s powerful computers requires scaling this technology further. In particular, the photon (particles of light) sources on this chip are not efficient enough to build quantum technology of useful scale.

“At DTU, we are now working on increasing the efficiency of these sources—which currently have an efficiency of just 1 percent—to near-unity. With such a source, it should be possible to build quantum photonic devices of vastly increased scale, and reap the benefits of quantum technology’s native physical advantage over classical computers in processing, communicating, and acquiring information, says postdoc at DTU Fotonik, Jeremy Adcock.

“With more efficient photon sources, we will be able to build more and different resource states, which will enable larger and more complex computations, as well as unlimited range secure quantum communications.”



More information:
Caterina Vigliar et al, Error-protected qubits in a silicon photonic chip, Nature Physics (2021). DOI: 10.1038/s41567-021-01333-w

Citation:
Optical chip protects quantum technology from errors (2021, September 28)
retrieved 29 September 2021

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Hexbyte Glen Cove Sustainable optical fibers developed from methylcellulose thumbnail

Hexbyte Glen Cove Sustainable optical fibers developed from methylcellulose

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Schematic illustration of a light coupled optical fibre and photographs of methylcellulose-based optical fibers under ambient light and UV light. Credit: Ville Hynninen and Nonappa

Researchers from Tampere University and Aalto University have developed optical fibers from methylcellulose, a commonly used cellulose derivative. The finding opens new avenues to short-distance optical fibers using sustainable and environmentally benign fiber processing. The finding was published in the journal Small.

The state-of-the-art silica glass optical fibers can carry over tens of kilometers with very low optical loss and provide high-capacity communication networks. However, their brittleness, low stretchability and energy intensiveness make them less suitable for local short-range applications and devices such as automotive, digital home appliances, fabrics, laser surgery, endoscopy and implantable devices based on optical fibers. The sustainable solution to these may be found within biopolymer-based optical fibers.

“The wide availability of cellulosic raw materials provides an excellent opportunity to unravel the hidden potential of renewable materials for through sustainable fiber processing routes,” says Associate Professor Nonappa, whose research team at Tampere University is developing biopolymer-based optical fibers for short-distance applications.

Conventionally, the polymer or plastic optical fibers are used for short-distance applications, but their processing may involve relatively high temperatures and the use of hazardous chemical treatment.

“By using methylcellulose hydrogel, we have shown that optical fibers can be produced at room temperature using a simple extrusion method without any chemical crosslinkers. The resulting fibers are highly transparent, mechanically robust, flexible and show low optical loss,” Nonappa states.

Biopolymer-based optical fibers suitable for multifunctional sensors

In addition to pure light signal transmission, the methylcellulose optical fibers can be feasibly modified and functionalized.

“The allows straightforward addition of various molecules and nanoparticles without compromising the or light propagation abilities of the fibers making them suitable for multifunctional sensors,” says doctoral researcher Ville Hynninen, the first author of the paper.

For example, incorporating an extremely low mass fraction of protein-coated gold nanoclusters produced luminescent optical fibers, and acted also as a fiber-based toxic metal ion sensor.

Overall, the presented results and the abundance of cellulosic derivatives and raw materials encourage further research and optimization of cellulose-derived optical components and devices.

“Luminescent Gold Nanocluster-Methylcellulose Composite Optical Fibers with Low Attenuation Coefficient and High Photostability” was published in Small.



More information:
Ville Hynninen et al. Luminescent Gold Nanocluster‐Methylcellulose Composite Optical Fibers with Low Attenuation Coefficient and High Photostability, Small (2021). DOI: 10.1002/smll.202005205

Journal information:
Small


Citation:
Sustainable optical fibers developed from methylcellulose (2021, January 28)
retrieved 28 January 2021
from https://phys.org/news/2021-01-sustainable-optical-fibers-methylcellulose.html

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part may be reproduced without the written permission. The content is provided for information purposes only.

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