Lasers & Holography

Researchers at Fraunhofer-Gesellschaft have developed a laser wielding robot (bow to your new robot overlord!) that can repair small cracks in a variety of materials.

It does this by spot-melting the surface under repair while an unspecified "powder" (presumably made out of the same material being repaired) is blown onto the melted surface. Using a fiber laser means that the area being repaired is highly localized and the surrounding areas undergo less stress when compared with traditional repair methods.

This laser method is very flexible. Depending on the components and applications concerned, we can use metals such as titanium, nickel and cobalt, hard metals and even ceramics. This allows us to seal cracks in tools, or rebuild chipped edges,” explains Dr. Steffen Nowotny. “The process enables us to accurately reconstruct several millimeters of material. This is sufficient to repair damage such as that caused by a bird strike to the delicate blades or disks of aircraft turbines.”

This is just one reason I'm not an early-adopter for anything. It always takes a while to work out the kinks and when it comes to my eyesight, I'll wait until there's sufficient long-term data available before anyone cuts or burn my vision back to 20/20.

A recent report from Otago and Oxford universities indicate that laser surgery for near-sighted patients could result in haze, glare and blurred vision as people reach their 60's and 70's.

The New Zealand Herald is reporting that tens of thousands of Kiwis may suffer from this problem in their later years. Searching the web, one would be left to think that this problem is going to only affect New Zealand but that's very unlikely.

Given that around 25,000 New Zealanders have had the surgery, Otago University head of ophthalmology Anthony Molteno said there could be significant legal class actions in the future, an issue that is causing major concern among eye surgeons.

"When we presented this work at the local conference, there was a stunned silence and some anxious questions," said Molteno.

In the procedure the central cornea is flattened. That provides better eyesight, but research shows that it seriously affects the movement of corneal cells, which affect sight. In a normal eye, the cells start at each end of the eye and migrate towards the centre. The top cells move quicker and meet the lower cells below the pupil. Where they meet, called the Hudson-Stahli Line, they create pigment, scattering light and causing glare, haze and blur.

As people age, that area increases and moderately affects eyesight but isn't a real problem, as the line is below the pupil.

Scientists at the University of Buffalo have developed a method to, as they put it:

allow scientists studying "non-model" organisms to test directly the function of certain genes, even in the absence of genome sequencing information

A (large) picture is available here.

Some writers have suggested that the next step will be advertising on the wings of butterflies but I hope more useful purposes will be found for this technique.

"As the laser heats up specific cells on the butterfly wing, genes that sit next to this regulatory sequence get turned on, allowing for specific clusters of cells on the wing to fluoresce," said Monteiro, assistant professor of ecology and evolutionary biology at Yale University.

NOAA has outfitted their ship, the Hi�ialakai with some scanning equipment that will allow them to take fast and accurate surveys of the ocean floor. More specifically coral reefs.

In the past they've had to rely on survery by eye or photograph but that has been slow and meant they could only survery small areas. In order to know how reefs are changing over time they needed a benchmark to measure against.

Enter the laser line scanner.

That system, called the SM-2000, was built by Northrop Grumman, and is owned and operated by Scientific Applications International Corporation (SAIC). The SM-2000 consists of a solid state blue-green laser that is aimed at a rotating mirror assembly. The mirrors quickly sweep the laser light across a downward pointing arc, while detector optics record the light reflected back from the seafloor. Variations in the reflected light are used to generate a gray scale image of the seafloor � essentially a black and white photograph of a strip of the ocean bottom that may be about 100 ft wide and could extend for miles.

I've added 10 of Lon Moore's photopolymer holograms to the store which are available for immediate purchase. These holograms were originally created for his Red Beam line and several have become collectible items.

The holograms include:

Saturn

The original Enterprise from Star Trek

Dracula

Among others.

Check them out.

Continue reading "Holograms by Lon Moore in the store"

The FEL (Free Electron Laser) team at JLAB (the Thomas Jefferson National Laboratory) have broken another power record.

In July 2004 they managed to produce 10kW of laser light and on October 30th they produced 14.2 kW at 1.61u.

Producing 14.2 kW is another record for the laser. "In this case, the smaller the wavelength in the infrared, the more difficult it was to reach at these tremendously high powers," said Fred Dylla, Jefferson Lab's chief technology officer and associate director of the Free-Electron Laser Div. "Reaching 14 kilowatts at 1.61 microns is a truly remarkable achievement, and we couldn't have done it without the hard work and dedication of the FEL staff and our colleagues at Jefferson Lab. The team created groundbreaking designs that resolved technical challenges never before seen, since these power levels are unprecedented."

Dylla said the laser's new capabilities will enhance a wide range of Navy applications, such as shipboard antimissile defense and other defense applications as well as manufacturing technologies and the support of scientific studies in chemistry, physics, biology and medicine.