Lasers can be used as tractor beams

Unfortunately, this will only work over close distances.

(BBC)- It is known that light can provide a "push", for example in solar sails that propel spacecraft on a "wind of light".

Now, in a paper on the Arxiv server, researchers from Hong Kong and China have calculated the conditions required to create a laser-based "pull".

Rather than a science fiction-style weapon, however, the approach would only work over small distances.

The effect is different from that employed in "optical tweezers" approaches, in which tiny objects can be trapped in the focus of a laser beam and moved around; this new force, the authors propose, would be one continuous pull toward the source.

And it relies on directly impinging on an object, making it distinct from an approach demonstrated in 2010 by Australian researchers whose trapping worked by heating air around a trapped particle.

The trick is not to use a standard laser beam, but rather one known as a Bessel beam, that has a precise pattern of peaks and troughs in its intensity.

Free-electron laser anti-missile system passes milestone

There is progress on the Navy's anti-missile laser weapon.

Last month, scientists at the Los Alamos National Lab demonstrated they are capable of producing the electrons needed to generate those megawatt-class laser beams. A preliminary design review began Thursday and continues today in Virginia, according to the Office of Naval Research.

"Until now, we didn't have the evidence to support our models," Dinh Nguyen, senior project leader for the Free Electron Laser program at the New Mexico lab, said in a news release.

British engineers develop lasers to fight off pirates

They could shoot some pirate's eye out. I'm OK with that.

Via The Telegraph:

British engineers are developing a new type of defence system that uses lasers to incapacitate pirates by dazzling them as they approach a ship.

The non-lethal weapon, which has been developed by defence company BAE Systems, is effective against moving targets more than a mile away.

The company has started developing the laser in response to the growing threat from pirates to commercial vessels, particularly off the coast of Somalia where there have been several high profile hijackings.

The device effectively hides the vessel carrying it in a bright green glare from the laser, forcing the pirates off course and leaving them unable to aim their weapons accurately.

Beam Powered Flight Prototype

Tiny helicopter kept aloft for mote than 12 hours by laser beams.

Ship Based Laser Shoots Down Drone (Video)

The US Navy demonstrates a laser capable of shooting down moving targets.

Saturday Night Fun: Mosquito killed by a Laser (video)

Video clip showing mosquitoes being killed by lasers.

Mosquito killed by a Laser (video)

Holmium Laser for BPH (video)

By the time they hit their 60th birthdays, half of all men will have a condition called benign prostatic hyperplasia, or BPH. It's a natural enlargement of the prostate gland that happens as you age. Treatment can be as simple as daily medication or as invasive as open surgery. Now doctors at Mayo Clinic are using a new laser technique to relieve symptoms for many men.

World's most powerful laser unveiled (video)

World's most powerful laser unveiled (video)

The world's most powerful laser was dedicated at the Livermore National Laboratory in California. It's designed to shore up the nation's aging nuclear weapons.