Photonic Products laser blog

A major hurdle to producing fusion energy using lasers has been swept aside, results in a new report show

The controlled fusion of atoms – creating conditions like those in our Sun – has long been touted as a possible revolutionary energy source.

However, there have been doubts about the use of powerful lasers for fusion energy because the “plasma” they create could interrupt the fusion.

An article in Science showed the plasma is far less of a problem than expected.

The report is based on the first experiments from the National Ignition Facility (Nif) in the US that used all 192 of its laser beams.

Along the way, the experiments smashed the record for the highest energy from a laser – by a factor of 20.

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EADS Astrium, Europe’s biggest space company, plans to put a solar power satellite in orbit to demonstrate the collection of solar power in space and its transmission via infrared laser to provide electricity on Earth.

Chief executive officer of Astrium, François Auque, said the system is at the testing stage, but that a viable system collecting and transmitting power from space could be within reach soon. Auque said space solar power is an attractive idea because it is an inexhaustible and clean form of energy. Unlike solar plants on Earth, orbital solar collectors can work around the clock, and there is no interference from clouds or atmospheric dusts or gases, which means the energy hitting photovoltaic cells in orbit is much greater than it would be for the same panels on the ground.

Earlier concepts of beaming power to Earth from space were criticized because they relied on microwaves to transmit the power to the ground, which has safety concerns, so Astrium plans to use infrared lasers instead, which means that even if they were misdirected people and objects hit by the laser beams could not be scorched.

The transmission of power via infrared laser has been tested in Astrium’s laboratories, and they are now concentrating on improving the system’s efficiency.

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How ‘Random’ Lasers Work: Natural Cavities Act Like Mirrors in Light-Emitting Plastics.

When University of Utah scientists discovered a new kind of laser that was generated by an electrically conducting plastic or polymer, no one could explain how it worked and some doubted it was real.

Now, a decade later, the Utah researchers have found these “random lasers” occur because of natural, mirror-like cavities in the polymers, and they say such lasers may prove useful for diagnosing cancer.

“Nobody knew how it worked until now,” says Z. Valy Vardeny, a distinguished professor of physics and senior author of the new study, published online Jan. 24 in the journal Nature Physics. “We succeeded in imaging the cavities. This is a big step in our understanding of this bizarre phenomenon, which not many people believed.”

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Producing a laser with a power of a terawatt — equal to one trillion watts — used to be impressive, but now the forefront of optical research power is measured in 1 quadrillion-watt units known as petawatts. But even that much power isn’t good enough for physics professor Todd Ditmire at the University of Texas at Austin.

Ditmire plans to build an exawatt laser with a power equivalent to 1,000 petawatts. But such a super-laser is still years away from actual development. In the meantime, Ditmire already has the most powerful laser in the world.

To get a sense of how much power an exawatt contains, compare it to a typical filament light bulb consuming about 100 W of electricity.

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Mandelson had been in charge.

The laser – first built 50 years ago – is used for everything from the internet to barcodes. Yet science funding allocation today would stop such visionary projects in their tracks.

IF YOU’RE planning to watch a DVD today, listen to a CD, play a computer game, go to a supermarket, browse the web, or do 100 other everyday tasks, spare a thought for the invention that has shaped our lives and revolutionised our manufacturing industries: the laser.

The name is an acronym for Light Amplification from the Stimulated Emission of Radiation. It works by pumping electrical energy into a “gain medium” (a gas, solid, liquid or plasma). This stimulates the emission of light, which is then amplified by being passed backwards and forwards in a cavity. In its simplest form, this consists of mirrors at either end. Light bounces back and forth off them, each time passing through the gain medium, and is amplified with each pass. Typically one mirror, called the output coupler, is partially transparent, which is how the output laser beam is emitted.

A laser beam is special because it’s what physicists call “coherent”; it consists of waves that all have the same frequency and are in step with one another. This makes it different from, say, a flashlight beam, the light waves from which will have different frequencies and typically be out of phase with one another.

The reason we’re celebrating the laser this year is that 50 years ago Theodore Maiman, a researcher at the Hughes Research Labs, built the first one, using a ruby crystal to produce a beam of red light. Later the same year, a group of physicists built the first gas laser, using a mixture of helium and neon.

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The remarkable feat was achieved by physicists working at the universities of Bristol, Glasgow and Southampton.

The light was controlled using holograms specially designed with ”knot theory” – a branch of abstract mathematics inspired by twists in shoelaces and rope.

The breakthrough paves the way for a new level of precision in laser technology, with applications ranging from traffic speed guns to height measurement.

Dr Mark Dennis, from the University of Bristol, said: ”In a light beam, the flow of light through space is similar to water flowing in a river.

”Although it often flows in a straight line – out of a torch, laser pointer, etc – light can also flow in whirls and eddies, forming lines in space called ‘optical vortices’.

”Along these lines, or optical vortices, the intensity of the light is zero (black).  ‘The light all around us is filled with these dark lines, even though we can’t see them.”

The team were able to create knots in optical vortices, using the sophisticated holograms to direct the flow of light, said Dr Dennis, lead author on the paper published in Nature Physics.

This research demonstrates a physical application for a branch of mathematics previously considered completely abstract.

Professor Miles Padgett from Glasgow University, who led the experiments, said: ”The sophisticated hologram design required for the experimental demonstration of the knotted light shows advanced optical control, which undoubtedly can be used in future laser devices.”

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Steroid injections into the eye slowed diabetes-related eye disease, though lasers remain the treatment of choice because of side effects related to the steroids, new research shows.

Researchers from the Johns Hopkins Wilmer Eye Institute gave 693 men and women who had diabetic retinopathy with macular edema either injections of a corticosteroid into their eyes as often as every four months or a laser photocoagulation, the standard treatment. The average age of the participants was 63.

Retinopathy is a long-term complication of diabetes that can lead to blindness. Macular edema, which can further interfere with vision, is a swelling of the central portion of the retina caused by fluid leakage.

Over time, retinopathy can advance to proliferative diabetic retinopathy, in which abnormal blood vessels grow on the optic nerve in the back of the eye, which communicates information from the retina to the brain, or elsewhere on the light-sensitive retina. The study authors found that steroid treatments reduced the risk of progression of diabetic retinopathy.

However, steroids did not prevent the progression of macular edema, according to the study.

And while steroids did help to improve the vision of participants, the results were no better than the laser treatments. Because the use of steroids in the eye can increase the risk of other eye diseases, including glaucoma and cataracts, lasers remain the treatment of choice for now, said lead study author Neil Bressler, a professor of ophthalmology and chief of the retina division of the eye institute.

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Many of the scientists who described the future in Nature held it close to the vest, offering more descriptions of the challenges in their field and fewer bombastic predictions of success to come. And then there are laser researchers. Meet Thomas Baer and Nicholas Bigelow. By 2020, they say, lasers with tiny apertures-the size of a single molecule-will help directly sequence DNA and RNA. Laser-based clocks will take note of the “drift in fundamental constants as the Universe expands.”

And that’s not all: “Next-generation lasers will allow the creation of new states of matter, compressing and heating materials to temperatures found only in the centres of massive stars, and at pressures that can squeeze hydrogen atoms together in a density 50 times greater than that of lead. The resulting fusion reactions may one day be harnessed to proved almost limitless carbon-free energy.”

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Boeing [NYSE: BA] announced today that it has accepted the Oshkosh Defense military truck that will carry a Boeing-built laser beam control system for the U.S. Army’s High Energy Laser Technology Demonstrator (HEL TD) program.

Boeing received the Oshkosh Heavy Expanded Mobility Tactical Truck (HEMTT) on Dec. 17 at the Oshkosh facility in Oshkosh, Wis.

“This demonstration program has successfully transitioned from the design phase to the fabrication phase,” said Gary Fitzmire, vice president and program director of Boeing Missile Defense Systems’ Directed Energy Systems unit.

“This transformational, solid-state laser weapon capability will provide speed-of-light, ultra-precision capability that will dramatically improve warfighters’ ability to counter rocket, artillery and mortar projectiles.”

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A double dose of circumcision, followed by some chili peppers, mystery roaches, and obsessive-compulsive guard dogs. It’s a potentially painful expedition into the world of Weird Science.

Lasers meet the fly penis: It’s all well and good to videotape duck erections if you want to study the impact of elaborate genitalia on speciation. But some scientists are experimentalists, and feel the need to manipulate an experimental system in the lab. Hence, we have a team from Berkeley using lasers to lop spines off a fly penis.

The spineless males were badly outcompeted by control flies when it came to mating. If these guys have received federal funding for this work, I fully expect to hear a politician making fun of it at some point in the future

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