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Using well-known materials and manufacturing processes, researchers have built an effective, passive, ultrathin laser isolator that opens new research avenues in photonics.
Category: computing – Page 348
Year 2017 đ
In 2015, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) developed the first on-chip metamaterial with a refractive index of zero, meaning that the phase of light could be stretched infinitely long. The metamaterial represented a new method to manipulate light and was an important step forward for integrated photonic circuits, which use light rather than electrons to perform a wide variety of functions.
Now, SEAS researchers have pushed that technology further â developing a zero-index waveguide compatible with current silicon photonic technologies. In doing so, the team observed a physical phenomenon that is usually unobservableâa standing wave of light.
The research is published in ACS Photonics. The Harvard Office of Technology Development has filed a patent application and is exploring commercialization opportunities.
Year 2012 đ
A Sierpinksi carpet is one of the more famous fractal objects in mathematics. Creating one is an iterative procedure. Start with a square, divide it into nine equal squares and remove the central one. That leaves eight squares around a central square hole. In the next iteration, repeat this process with each of the eight remaining squares and so on (see above). One interesting problem is to find the area of a Sierpinski triangle. Clearly this changes with each iteration. Assuming the original square has area equal to 1, the area after the first iteration is 8/9. After the second iteration, it is (8Ă·9)^2; after the third it is (8Ă·9)^3 and so on.
Year 2019 đ
Semiconducting carbon nanotubes (CNTs) printed into thin films offer high electrical performance, significant mechanical stability, and compatibility with low-temperature processing. Yet, the implementation of low-temperature printed devices, such as CNT thin-film transistors (CNT-TFTs), has been hindered by relatively high process temperature requirements imposed by other device layersâdielectrics and contacts. In this work, we overcome temperature constraints and demonstrate 1Dâ2D thin-film transistors (1Dâ2D TFTs) in a low-temperature (maximum exposure â€80 °C) full print-in-place process (i.e., no substrate removal from printer throughout the entire process) using an aerosol jet printer. Semiconducting 1D CNT channels are used with a 2D hexagonal boron nitride (h-BN) gate dielectric and traces of silver nanowires as the conductive electrodes, all deposited using the same printer.
Year 2009 This is awesome đ đ
The title character of Ray Bradburyâs book The Illustrated Man is covered with moving, shifting tattoos. If you look at them, they will tell you a story.
New LED tattoos from the University of Pennsylvania could make the Illustrated Man real (minus the creepy stories, of course). Researchers there are developing silicon-and-silk implantable devices which sit under the skin like a tattoo. Already implanted into mice, these tattoos could carry LEDs, turning your skin into a screen.
The silk substrate onto which the chips are mounted eventually dissolves away inside the body, leaving just the electronics behind. The silicon chips are around the length of a small grain of rice â about 1 millimeter, and just 250 nanometers thick. The sheet of silk will keep them in place, molding to the shape of the skin when saline solution is added.
This would be great for teleporting objects for shipping across the planet or cosmos eventually. đ
Scientists have created a âholographic wormholeâ inside a quantum computer for the first time.
The pioneering experiment allows researchers to study the ways that theoretical wormholes and quantum physics interact, and could help solve some of the most difficult and perplexing parts of science.
The wormhole is theoretical: researchers did not produce an actual rupture in space and time. But the experimental creation of one inside the quantum computer â which saw a message sent between two simulated blackholes â nonetheless allows scientists to examine how they might work, after almost 100 years of theory.
Conventional light sources for fiber-optic telecommunications emit many photons at the same time. Photons are particles of light that move as waves. In today ÂÂs telecommunication networks, information is transmitted by modulating the properties of light waves traveling in optical fibers, similar to how radio waves are modulated in AM and FM channels.
In quantum communication, however, information is encoded in the phase of a single photon â the photon ÂÂs position in the wave in which it travels. This makes it possible to connect quantum sensors in a network spanning great distances and to connect quantum computers together.
Researchers recently produced single-photon sources with operating wavelengths compatible with existing fiber communication networks. They did so by placing molybdenum ditelluride semiconductor layers just atoms thick on top of an array of nano-size pillars (Nature Communications, âSite-Controlled Telecom-Wavelength Single-Photon Emitters in Atomically-thin MoTe 2 â).
Saturnâs moon Titan is one of the weirdest and most intriguing worlds in our solar system. It is the only place we know of in the universe for sure beyond Earth that has rivers, lakes and larger bodies of liquid, but on Titan these features are filled with flammable hydrocarbons like methane and ethane.
Studying Titan in depth has been difficult due to a thick atmosphere of clouds and haze, but NASAâs James Webb Space Telescope (JWST) is giving scientists their first detailed glimpse of those clouds, and by extension, the weather patterns at work on this unique world.
âWe had waited for years to use Webbâs infrared vision to study Titanâs atmosphere,â said JWST Principal Investigator Conor Nixon. âDetecting clouds is exciting because it validates long-held predictions from computer models about Titanâs climate, that clouds would form readily in the mid-northern hemisphere during its late summertime when the surface is warmed by the Sun.â
An unusual teleportation experiment uses ordinary quantum physics, but was inspired by tunnels in an exotic âtoy universeâ.
A small satellite developed by MIT engineers has set a new record for data transmission between a satellite and Earth. The TeraByte InfraRed Delivery (TBIRD) system used a laser to beam huge amounts of data at up to 100 gigabits per second (Gbps).
This data transmission speed is far greater than most connections youâll get between the sky and the ground. SpaceXâs Starlink satellite internet offers up to 500 Mbps to Premium customers, and even the International Space Stationâs data transmission tops out around 600 Mbps. That makes TBIRD up to 200 times faster.
The key difference is that most satellites communicate with ground stations via radio waves. TBIRD, on the other hand, uses laser light, which can carry up to 1,000 times more data in each transmission. Lasers come with their own hurdles though â the beams are much narrower, requiring more precise alignment between transmitter and receiver. And the light can be distorted by the atmosphere, leading to data loss. So TBIRD was designed to overcome these issues.