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It has been known for a century that electromagnetic fields can transport not only energy and linear momentum but also angular momentum. However, it was not until twenty years ago, with the discovery in laser optics of experimental techniques for the generation, detection and manipulation of photons in well-defined, pure orbital angular momentum (OAM) states, that twisted light and its pertinent optical vorticity and phase singularities began to come into widespread use in science and technology. We have now shown experimentally how OAM and vorticity can be readily imparted onto radio beams. Our results extend those of earlier experiments on angular momentum and vorticity in radio in that we used a single antenna and reflector to directly generate twisted radio beams and verified that their topological properties agree with theoretical predictions. This opens the possibility to work with photon OAM at frequencies low enough to allow the use of antennas and digital signal processing, thus enabling software controlled experimentation also with first-order quantities, and not only second (and higher) order quantities as in optics-type experiments. Since the OAM state space is infinite, our findings provide new tools for achieving high efficiency in radio communications and radar technology.

and how can we use this?

Progress in atomic, optical and quantum science1, 2 has led to rapid improvements in atomic clocks. At the same time, atomic clock research has helped to advance the frontiers of science, affecting both fundamental and applied research. The ability to control quantum states of individual atoms and photons is central to quantum information science and precision measurement, and optical clocks based on single ions have achieved the lowest systematic uncertainty of any frequency standard3, 4, 5. Although many-atom lattice clocks have shown advantages in measurement precision over trapped-ion clocks6, 7, their accuracy has remained 16 times worse8, 9, 10. Here we demonstrate a many-atom system that achieves an accuracy of 6.4 × 10−18, which is not only better than a single-ion-based clock, but also reduces the required measurement time by two orders of magnitude. By systematically evaluating all known sources of uncertainty, including in situ monitoring of the blackbody radiation environment, we improve the accuracy of optical lattice clocks by a factor of 22. This single clock has simultaneously achieved the best known performance in the key characteristics necessary for consideration as a primary standard-stability and accuracy. More stable and accurate atomic clocks will benefit a wide range of fields, such as the realization and distribution of SI units11, the search for time variation of fundamental constants12, clock-based geodesy13 and other precision tests of the fundamental laws of nature. This work also connects to the development of quantum sensors and many-body quantum state engineering14 (such as spin squeezing) to advance measurement precision beyond the standard quantum limit.

"We have made optical systems at the microscopic scale that amplify light and produce ultra-narrowband spectral output," explained J. Gary Eden, a professor of electrical and computer engineering (ECE) at Illinois. "These new optical amplifiers are well-suited for routing optical power on a chip containing both electronic and optical components.

In this article the authors describe an improvement of their optical microscope techniques for which some of the received a Nobel prize in the past. They achieve resolutions far beyond the optical diffraction limit which is supposed to limit detail resolution due to quantum-mechanical effects. Their techniques include structured illuminiation (producing interference patterns), switchable fluorescent markers as well as multi-frame super resolution enhancement. Authors are able to take a single image in about 0.3 seconds which allows the study of protein processes in the cell: http://spon.de/vgTb7 . Although it is hard to imagine the application of many of these techniques for telescopes (except for super resolution), I am wondering if any of this could help building telescopes with increased optical power or reduced weight. Any ideas..?

This is the first time that significant pair production has been demonstrated in a structure that can be electrically self-pumped and which can form the basis for passive optical circuitry, bringing us markedly closer to complete integration of quantum optical technologies.

Physicists in the US have made the first ultrathin flat lens. Thanks to its flatness, the device eliminates optical aberrations that occur in conventional lenses with spherical surfaces. As a result, the focusing power of the lens also approaches the ultimate physical limit set by the laws of diffraction.

Really nice indeed! The new flat ultrathin lens is different in that it is a nanostructured "metasurface" made of optically thin beam-shaping elements called optical antennas, which are separated by distances shorter than the wavelength of the light they are designed to focus. These antennas are wavelength-scale metallic elements that introduce a slight phase delay in a light ray that scatters off them. The metasurface can be tuned for specific wavelengths of light by simply changing the size, angle and spacing between the nanoantennas. "The antenna is nothing more than a resonator that stores light and then releases it after a short time delay," Capasso says. "This delay changes the direction of the light in the same way that a thick glass lens would." The lens surface is patterned with antennas of different shapes and sizes that are oriented in different directions. This causes the phase delays to be radially distributed around the lens so that light rays are increasingly refracted further away from the centre, something that has the effect of focusing the incident light to a precise point.

Weird.

This reminds me a 2013 paper on how to perform derivatives, integrals and even time reversal in optical fibres: http://www.nature.com/srep/2013/130403/srep01594/full/srep01594.html "The manipulation of dynamic Brillouin gratings in optical fibers is demonstrated to be an extremely flexible technique to achieve, with a single experimental setup, several all-optical signal processing functions. In particular, all-optical time differentiation, time integration and true time reversal are theoretically predicted, and then numerically and experimentally demonstrated."

Would this kind of computer be more space environment resistive?

They were able to compare the ticking rates of two optical clocks separated by 2000 km, with the objective of computing sea level based on the effect gravity has on the clock ticking rate. They did the experiment using glass optical fibers, but I wonder if we could one day do the same from orbit, to measure the gravitational field around Earth.

isn't this is effectively what pacome has been doing with his time for the last few years? e.g. http://arxiv.org/pdf/1308.6766v1.pdf also mentioning the ACES experiment

From the article: By the end of September 2014, Jason Budinoff, an aerospace engineer at NASA's Goddard Space Flight Center (Greenbelt, MD), is expected to complete the first imaging telescopes ever assembled almost exclusively from 3D-manufactured components. The devices' optics and electronics will be fabricated using conventional methods. "As far as I know, we are the first to attempt to build an entire instrument with 3D printing," says Budinoff. He is building a fully functional 50 mm camera whose outer tube, baffles, and optical mounts are all printed as a single structure. The instrument is appropriately sized for a CubeSat (a small satellite made of individual units each about 100 mm on a side). 

12 new NIAC 1 studies - many topics familiar to us ... please have a look at those closest to your expertise to see if there is anything new/worth investigating (and in general to be knowledgeable on them since we will get questions sooner or later on them)
Principal Investigator Proposal Title Organization City, State, Zip Code
Atchison, Justin Swarm Flyby Gravimetry Johns Hopkins University Baltimore, MD 21218-2680
Boland, Eugene Mars Ecopoiesis Test Bed Techshot, Inc. Greenville, IN 47124-9515
Cash, Webster The Aragoscope: Ultra-High Resolution Optics at Low Cost University of Colorado Boulder, CO 80309-0389
Chen, Bin 3D Photocatalytic Air Processor for Dramatic Reduction of Life Support Mass & Complexity NASA ARC Moffett Field, CA 94035-0000
Hoyt, Robert WRANGLER: Capture and De-Spin of Asteroids and Space Debris Tethers Unlimited Bothel, WA 98011-8808
Matthies, Larry Titan Aerial Daughtercraft NASA JPL Pasadena, CA 91109-8001
Miller, Timothy Using the Hottest Particles in the Universe to Probe Icy Solar System Worlds John Hopkins University Laurel, MD 20723-6005
Nosanov, Jeffrey PERISCOPE: PERIapsis Subsurface Cave OPtical Explorer NASA JPL Pasadena, CA 91109-8001
Oleson, Steven Titan Submarine: Exploring the Depths of Kraken NASA GRC Cleveland, OH 44135-3127
Ono, Masahiro Comet Hitchhiker: Harvesting Kinetic Energy from Small Bodies to Enable Fast and Low-Cost Deep Space Exploration NASA JPL Pasadena, CA 91109-8001
Streetman, Brett Exploration Architecture with Quantum Inertial Gravimetry and In Situ ChipSat Sensors Draper Laboratory Cambridge, MA 02139-3539
Wiegmann, Bruce Heliopause Electrostatic Rapid Transit System (HERTS) NASA MSFC Huntsville, AL 35812-0000

Eh, the swarm flyby gravimetry is very similar to the "measuring gravitational fields" project I proposed in the brewery

Two research teams have designed an optical gate that can 'switch off' a stream of photons as well as store them ... good news for optical communications as well as future photon-based quantum information systems.

The best paper on transformation optics written ever :-)

Concerning the fabrication... as usual, no idea. I agree that this is the main drawback of MM, and certainly difficult to overcome. I would double check that number, because its value is related with the beam shape of Fig. 1 A. I believe that the simulations are correct, it's just a detail.

wow ... still publishing despite babysitting and new job!!

Cheap and scalable invisibility cloaks being developed. The setup is so trivial that I would almost call it a "trick" (as in "Magicians trick"): 6 prisms of n=1.78 glass. Nontheless, it does the job of cloaking an object at visible wavelengths and from several directions.

Is this really new? I don't know, but I know that the original idea of cloaking was pretty different. When cloaking as an application of transformation optics became popular people tried to make devices that work for any incidence angle, any polarization and in full wave optics (not just ray approximation). This is really hard to achieve and I guess that the people that tried to make such devices knew exactly that the task becomes almost trivial by dropping at least two of the three conditions above.

I think it is very easy to call something trivial when you're not the one who invested considerable time (5 min in my case) to design a cloaking device and fill the coffee mugs with water... Also, I did not really violate that many conditions: true I reduced the number of dimensions in which the device works to 1 (as opposed to the 2 dimensions of many metamaterial cloaks). However the polarization should not be affected in my setup as well as the wave phase and wave vector (so it works in full wave optics) - apart maybe from the imperfect lens distortion, but hey I was improvising.

Check the landing video from the onboard camera - Guido: how well would our optical flow algorithm cope with such images? Looks quite complicated to me....

Note that videos there are said to be "thumbnail" quality, so I think videos with higher resolution (and possibly frame rate) have been acquired, just that they were not downloaded yet.

optical transistors?

optical transistors coming?

We don't have Science Express subscription here, so I have to wait till the normal paper is out. From what I heard about it, I doubt that this would have made it to Science without the names Pendry and Wegener in the autor list! Certainly, they are two of the smartest guys in Metamaterials, but they are also two of the absolut class A sellers. Pendry by definition is the first in whatever (at least in HIS talks...) but apart from this he's a very nice guy. Better let's not try to characterize Wegener...

more transformation optics ... 

I still believe that it is worth to check the thermal, mechanical and chemical properties of the developed metamaterials. For hyperbolic re-entries the radiation is still the dominating heat load source and a dominating bandwith may be indentified. A resistive metamaterial should be placed on the nose cap of the entry body in order to reduce local radiation heat load.

The integrated total reflectance from carbonnanotube arrays is three times lower than the lowest-ever reported values of optical reflectance from any material, making it the darkest man-made material ever.

The object being imaged or stimulated with subwavelength accuracy does not need to be in the immediate proximity of the superlens or field concentrator: an optical mask can be designed that creates constructive interference of waves known as superoscillat