Tag Archives: lasers

NASA Beams “Hello, World!” Video from Space via Laser

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Optical communication tools like OPALS use focused laser energy to reach data rates between 10 and 1,000 times higher than current space communications, which rely on radio portions of the electromagnetic spectrum.

Because the space station orbits Earth at 17,500 mph, transmitting data from the space station to Earth requires extremely precise targeting. The process can be equated to a person aiming a laser pointer at the end of a human hair 30 feet away and keeping it there while walking.

via NASA Beams “Hello, World!” Video from Space via Laser | NASA.

NASA’s LLCD tests confirm laser communication capabilities in space

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The LLCD is a demonstration of the practicality of using broadband lasers for deep space communications with download speeds orders of magnitude greater than conventional radio communications. With the ability to download data to Earth at 622 megabits per second (Mbps) and upload at 20 Mbps, the LLCD transmitted a record-breaking download on October 20 from lunar orbit using a pulsed laser beam that was picked up by the main LLCD ground station in New Mexico, which is one of three set up in the US and Spain.

via NASA’s LLCD tests confirm laser communication capabilities in space.

Stealth camera takes pictures virtually in the dark

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In the team’s setup, low-intensity pulses of visible laser light scan an object of interest. The laser fires a pulse at a given location until a single reflected photon is recorded by a detector; each illuminated location corresponds to a pixel in the final image.

Variations in the time it takes for photons from the laser pulses to be reflected back from the object provides depth information about the body — a standard way of revealing three-dimensional structure. However, the algorithm developed by Kirmani and his colleagues provides that information using one-hundredth the number of photons required by existing light detection and ranging (LIDAR) techniques, which are commonly used in remote mapping or measuring forest biomass, for instance.

via Stealth camera takes pictures virtually in the dark : Nature News & Comment.

Persuading light to mix it up with matter

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Their findings suggest that it’s possible to alter the electronic properties of a material — for example, changing it from a conductor to a semiconductor — just by changing the laser beam’s polarization. Normally, to produce such dramatic changes in a material’s properties, “you have to do something violent to it,” Gedik says. “But in this case, it may be possible to do this just by shining light on it. That actually modifies how electrons move in this system. And when we do this, the light does not even get absorbed.”

via Persuading light to mix it up with matter – MIT News Office.

It will take some time to assess possible applications, Gedik says. But, he suggests, this could be a way of engineering materials for specific functions. “Suppose you want a material to do something — to conduct electricity, or to be transparent, for example. We usually do this by chemical means. With this new method, it may be possible to do this by simply shining light on the materials.”

Scientists Build Lasers Out of Sound, Call Them Phasers

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Sound lasers work on a similar principle. For Mahboob and his team’s phaser, a mechanical oscillator jiggles and excites a bunch of phonons, which relax and release their energy back into the device. The confined energy causes the phaser to vibrate at its fundamental frequency but with at a very narrow wavelength. The sound laser produces phonons at 170 kilohertz, far above human hearing range, which peters out around 20 kilohertz. The entire device is etched onto an integrated circuit that’s about 1 cm by 0.5 cm.

via Pew Pew! Scientists Build Lasers Out of Sound, Call Them Phasers | Wired Science | Wired.com.

German Military Laser Destroys Targets Over 1Km Away

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For its finale, the laser’s ability to track a very small ballistic target was demonstrated. It honed in on and destroyed a steel ball 82mm in diameter traveling at 50 meters per second. The small ball was meant to simulate an incoming mortar round. Rheinmetall says their laser will reduce the time required for C-RAM – Counter Rocket, Artillery, and Mortar measures – to a matter of seconds, even in adverse weather conditions. In fact, weather at the Ochsenboden Proving Ground in Switzerland where the demonstration was carried out included ice, rain, snow, and extremely bright sunlight – far from ideal.

via German Military Laser Destroys Targets Over 1Km Away | Singularity Hub.