Quantum physics enables revolutionary imaging method
Date: August 28, 2014
Source: University of Vienna
Summary: Researchers have developed a fundamentally new quantum imaging technique with strikingly counter-intuitive features. For the first time, an image has been obtained without ever detecting the light that was used to illuminate the imaged object, while the light revealing the image never touches the imaged object.
Pic: A new quantum imaging technique generates images with photons that have never touched to object — in this case a sketch of a cat. This alludes to the famous Schrödinger cat paradox, in which a cat inside a closed box is said to be simultaneously dead and alive as long there is no information outside the box to rule out one option over the other. Similarly, the new imaging technique relies on a lack of information regarding where the photons are created and which path they take. Credit: Copyright: Patricia Enigl, IQOQI
Researchers from the Institute for Quantum Optics and Quantum Information (IQOQI), the Vienna Center for Quantum Science and Technology (VCQ), and the University of Vienna have developed a fundamentally new quantum imaging technique with strikingly counterintuitive features. For the first time, an image has been obtained without ever detecting the light that was used to illuminate the imaged object, while the light revealing the image never touches the imaged object.
In general, to obtain an image of an object one has to illuminate it with a light beam and use a camera to sense the light that is either scattered or transmitted through that object. The type of light used to shine onto the object depends on the properties that one would like to image. Unfortunately, in many practical situations the ideal type of light for the illumination of the object is one for which cameras do not exist.
The experiment published in Nature this week for the first time breaks this seemingly self-evident limitation. The object (e.g. the contour of a cat) is illuminated with light that remains undetected. Moreover, the light that forms an image of the cat on the camera never interacts with it. In order to realise their experiment, the scientists use so-called “entangled” pairs of photons. These pairs of photons — which are like interlinked twins — are created when a laser interacts with a non-linear crystal. In the experiment, the laser illuminates two separate crystals, creating one pair of twin photons (consisting of one infrared photon and a “sister” red photon) in either crystal. The object is placed in between the two crystals. The arrangement is such that if a photon pair is created in the first crystal, only the infrared photon passes through the imaged object. Its path then goes through the second crystal where it fully combines with any infrared photons that would be created there.
With this crucial step, there is now, in principle, no possibility to find out which crystal actually created the photon pair. Moreover, there is now no information in the infrared photon about the object. However, due to the quantum correlations of the entangled pairs the information about the object is now contained in the red photons — although they never touched the object. Bringing together both paths of the red photons (from the first and the second crystal) creates bright and dark patterns, which form the exact image of the object.
Stunningly, all of the infrared photons (the only light that illuminated the object) are discarded; the picture is obtained by only detecting the red photons that never interacted with the object. The camera used in the experiment is even blind to the infrared photons that have interacted with the object. In fact, very low light infrared cameras are essentially unavailable on the commercial market. The researchers are confident that their new imaging concept is very versatile and could even enable imaging in the important mid-infrared region. It could find applications where low light imaging is crucial, in fields such as biological or medical imaging.
Story Source: The above story is based on materials provided by University of Vienna. Note: Materials may be edited for content and length.
Journal Reference: Gabriela Barreto Lemos, Victoria Borish, Garrett D. Cole, Sven Ramelow, Radek Lapkiewicz, Anton Zeilinger. Quantum imaging with undetected photons. Nature, 2014; 512 (7515): 409 DOI: 10.1038/nature13586
Cite This Page: MLA APA Chicago: University of Vienna. “Quantum physics enables revolutionary imaging method.” ScienceDaily. ScienceDaily, 28 August 2014.
universal-abyss: Crikey, so the light never actually touches the object being imaged, yet can create an exact image - this is utterly extraordinary! This takes quantum imaging to a whole new level - and, wow is it cool! This should truly twist and bend your mind at the awesomeness of quantum physics. The potentials it may bring to medical and biological imaging are simply astounding to consider. Just, wow!
Arthur E Smith focuses images on his early apparatus for photomicrography.
Simply obtained by photographing images upon the microscope’s eyepiece, the images produced became the focal point (pun not intended) of the 1909 book Nature through Microscope & Camera by Richard Kerr.
This is Kaindy Lake which is located in Kazakhstan’s portion of the Tian Shan Mountains. The lake has not always been here and is the result of a natural dam created by a landslide that was triggered by an earthquake in 1911. Since then, rainwater filled the valley and created the lake which is 400 metres long and 30 metres at its deepest point.
The lake is famous for its scenic beauty, in particular the sunken forest. The trunks of spruce trees rise out of the lake and look amazingly out of place amongst the calm water.
For more information see: http://www.caravanistan.com/travel/kazakhstan/kaindy-lake-sunken-forest/
Photo courtesy of Zhirayr Nersessian.
29 August 2014
Blood and Gold
One of the biggest hopes for nanotechnology is the design of molecules to support living processes. Pictured here, tiny gold ‘nanorods’ cover the surface of red blood cells – a snapshot of biotechnology in action, fixed in time with a blue chemical agent. Each gold nanorod holds tiny ‘pockets’, called aptamers, filled with a blood thinning chemical called thrombin. Firing a laser at these harmless specks of gold causes them to melt just enough to release the thrombin, preventing blood from clotting. The process can be reversed by triggering the release of a different chemical which counteracts the thrombin, allowing the blood to clot naturally. Intravenous injections of chemicals like heparin are currently used all over the world to prevent dangerous blood clots after operations. In the future, nanotechnology could be used instead, with the advantage of controllable clotting at the flick of a laser switch.
Written by John Ankers
Sailing stones, sliding rocks, and moving rocks all refer to a geological phenomenon where rocks move in long tracks along a smooth valley floor without human or animal intervention. The Racetrack Playa a barren lakebed in Death Valley National Park is home to one of the worlds natural wonders: ‘sailing stones’ that mysteriously meander across the dried mud, leaving tracks in their wake. Since the 1940s, these rocks have fueled wonder and speculation because no one had seen them in action until now.
THE INSECT THAT CAME BACK TO LIFE
By 1920, the Lord Howe Island stick insect (Dryococelus australis) was thought to be extinct as a result of rats being introduced to the island. Over 80 years later, in 2001, however, two Australians scientists discovered a group of 24 of these large stick insects.
Since the discovery, the insects have been successfully bred in captivity at Melbourne Zoo. As of 2012, the population of the Dryococelus australis has reached over 9,000 individuals, with thousands of eggs waiting to hatch. The ultimate goal is to place the insects back on their home island, after the planned eradication of rats.
These stick insects live for about 2 years and measure up to 15 cm (6 inches). The nymphs are green and diurnal, and turn black and nocturnal as they become adults. Today, they are still considered critically endangered.
Here is a photo of lava from the Kilauea Volcano in Hawaii Volcanoes National Park flowing into the Pacific Ocean. This flow has been dubbed “The banana flow” as there is a forested area where bananas grow near the top of the volcano!
It predominantly erupts basaltic lava in effusive eruptions, although occasionally it experiences explosive eruptions as well.
Kilauea volcano is one of the most active on Earth and lava has created more than 500 acres of new land along the coastline.
Photo courtesy of David Jordan
Hydnellum peckii is an inedible fungus, and a member of the genus Hydnellum of the family Bankeraceae. It is a hydnoid species, producing spores on the surface of vertical spines or tooth-like projections that hang from the undersurface of the fruit bodies. It is found in North America, Europe, and was recently discovered in Iran (2008) and Korea (2010). Hydnellum peckii is a mycorrhizal species, and forms mutually beneficial relationships with a variety of coniferous trees, growing on the ground singly, scattered, or in fused masses.
The fruit bodies typically have a funnel-shaped cap with a white edge, although the shape can be highly variable. Young, moist fruit bodies can “bleed” a bright red juice that contains a pigment known to have anticoagulant properties similar to heparin. The unusual appearance of the young fruit bodies has earned the species several descriptive common names, including strawberries and cream, the bleeding Hydnellum, the bleeding tooth fungus, the red-juice tooth, and the Devil’s tooth. Although Hydnellum peckii fruit bodies are readily identifiable when young, they become brown and nondescript when they age.
The species was first described scientifically by American mycologist Howard James Banker in 1913. Italian Pier Andrea Saccardo placed the species in the genus Hydnum in 1925, while Walter Henry Snell and Esther Amelia Dick placed it in Calodon in 1956; Hydnum peckii (Banker) Sacc. and Calodon peckii Snell & E.A. Dick are synonyms of Hydnellum peckii.
The fungus is classified in the stirps (species thought to be descendants of a common ancestor) Diabolum of the genus Hydnellum, a grouping of similar species with the following shared characteristics: flesh that is marked with concentric lines that form alternating pale and darker zones (zonate); an extremely peppery taste; a sweetish odor; spores that are ellipsoid, and not amyloid (that is, not absorbing iodine when stained with Melzer’s reagent), acyanophilous (not staining with the reagent Cotton Blue), and covered with tubercules; the presence of clamp connections in the hyphae. Molecular analysis based on the sequences of the internal transcribed spacer DNA of several Hydnellum species placed H. peckii as most closely related to H. ferrugineum and H. spongiosipes.
The specific epithet honors mycologist Charles Horton Peck. The fungus is known in the vernacular by several names, including “strawberries and cream”, the “bleeding Hydnellum”, the “red-juice tooth”, “Peck’s hydnum”, the “bleeding tooth fungus”, and the “devil’s tooth”.
photo and text from Rare Plants
Power of the Sun: Elusive Solar Neutrinos Detected, a Cosmic First
Tiny particles forged in the heart of the sun have been detected for the first time, offering scientists a glimpse into the nuclear fusion core of our closest star.
The subatomic particles, called neutrinos, are hallmarks of the dominant fusion process insidethe sun. Created in the first step of a reaction sequence responsible for the majority of the sun’s fusion, the particles have long eluded detection. Now, an international collaboration of more than 100 scientists working with the Borexino detector in Italy has made the first measurements of these elusive particles.