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Engineers at Stevens Institute of Technology have developed a technique to optically modulate the frequency of a laser beam and create a signal that is disrupted significantly less by environmental factors, says Dr. Rainer Martini. The research provides for enhanced optical communications, allowing mobile units not tied to fiber optic cable to communicate in the range of 100 GHz and beyond, the equivalent of 100 gigabytes of data per second. Eventually, the team hopes to extend the reach into the terahertz spectrum. The frequency or amplitude modulation of middle infrared quantum cascade lasers has been limited by electronics, which are barely capable of accepting frequencies of up to 10 GHz by switching a signal on and off.  Marini and his team have developed a method to optically induce fast amplitude modulation in a quantum cascade laser to control the laser's intensity. Their amplitude modulation system employed a second laser to modulate the amplitude of the middle infrared laser, using light to control light. The current detector is only capable of detecting frequencies up to 10 GHz, but Dr. Martini is confident that a new detector will make the system capable of much higher frequencies. With an optical system that is stable enough, satellites may one day convert to laser technology, resulting in a more mobile military and super-sensitive scanners, as well as faster Internet for the masses, says Martini. Ref.: "Optically induced fast wavelength modulation in a quantum cascade laser," Applied Physics Letters, July 7, 2010.

Researchers at LaserMotive have devised a way to beam lasers to power military bases and drones, possibly helping to save lives, since delivering fuel to battle zones can be a dangerous task in wartime. Although still largely in the R&D stage, laser power beaming has many other potential uses, which include powering vehicles, replacing electric power wiring and transmission lines in difficult places, and even launching rockets into orbit. The beam is about 8 inches wide as it leaves the transmitter - and then spreads wider as it travels. The beam emitter is located at a ground-based unit and operated by a person, who could control it from the same location or remotely from an entirely different place altogether. The operator uses the machine to fire the laser beam at a photovoltaic collector located on an unmanned autonomous vehicle (UAV), small plane, or helicopter. The current range of the system is about a kilometer. When the laser hits the photovoltaic device, the photons in the light beam are converted to electricity to fly the AUV. Topics: AI/Robotics | Energy | Physics/Cosmology | Survival/Defense

Creating a laser that can melt a soda can in a lab is a finicky enough task. Later this year, scientists will put a 40,000-pound chemical laser in the belly of a gunship flying at 300 mph and take aim at targets as far away as five miles. And we're not talking aluminum cans. Boeing's new Advanced Tactical Laser will cook trucks, tanks, radio stations-the kinds of things hit with missiles and rockets today. Whereas conventional projectiles can lose sight of their target and be shot down or deflected, the ATL moves at the speed of light and can strike several targets in rapid succession.

This method may potentially be suitable for designing novel light sources resembling lasers that work in the x-ray range. Among other applications, they might allow building more powerful computer chips.

LEDsThe strange quantum state of entanglement isn't just challenging to think about, it's hard to create. This "spooky" phenomenon-in which two particles are linked, even if they're separated by distance-can be created by scientists in the lab using bulky lasers. But scientists published a study in Nature today in which they created a light-emitting diode (LED) that produces entangled photons.