It’s been a busy year in a number of way which is why I haven’t been posting too many lab updates and tutorials.
I’ve got a number of tutorials in the pipeline and pictures that need taking but the next two weeks promise to be just as full so I’m not sure how much I’ll be able to get to while I’ve got the time off my "day job." We’ll see though.
Click through for some pictures and descriptions of what I’ve been up to.
Researchers at NIST have developed a simpler method to "clean" carbon nanotube structures using an excimer laser.
In a forthcoming issue of Chemical Physics Letters, the NIST/NREL team describes how pulses from an excimer laser greatly reduce the amount of carbon impurities in a sample of bulk carbon single-walled nanotubes, without destroying tubes. Both visual examination and quantitative measurements of material structure and composition verify that the resulting sample is "cleaner". The exact cleaning process may need to be slightly modified depending on how the nanotubes are made, the authors note. But the general approach is simpler and less costly than conventional "wet chemistry" processes, which can damage the tubes and also require removal of solvents afterwards.
NIST researchers have come up with a new method that may help to identify defects in superconductors, using a lattice of laser beams controlling a Bose-Einstein condensate.
The JILA experiments were performed with 3 million rubidium atoms held in a magnetic trap. A superfluid of vortices was created by spinning the trap. The reddish BEC cloud, about 100 micrometers in diameter, contained about 100 hollow vortices, like a spinning bundle of fibers. Lasers were used to set up optical lattices grids of light in an arrangement of energy peaks and troughs in triangular and square patterns and focus them onto the BEC.
Because BECs and optical lattices can be precisely controlled, the technique may be useful in studying more mysterious patterned superfluids, such as superconductors.
Photonics.com reports that several groups have developed methods of cooling mirrors using not much more than beams from lasers. The research is aimed at revealing quantum effects in our macroscopic world.
Cooling occurs when photons bounce off a springlike structure with a natural resonant frequency. If a laser is off that frequency, the light acts like an ultracold viscous fluid, damping movement and, therefore, cooling the structure. The key to achieving the lowest possible temperature is to have a low-mass, highly reflective mirror mounted on a springy structure of high mechanical quality.
If you know someone who’s recently bought a laser pointer (of any kind) please take the time to make sure that they know not to point the thing at aircraft (really, any other person).
It doesn’t matter that most pointer beams will expand too much to be any danger to the pilots, it doesn’t matter if the power levels are too low to be of any real concern.
This is no joke. The more often that this sort of thing happens, the more likely it becomes that our lasers will become so regulated here in the US that even we can’t get hold of decent power levels anymore.
What prompted this public service announcement?
Recently authorities raided a house in CA looking for a laser that’s been shone at aircraft in the area. Particularly aircraft attempting to land at the Mineta International Airport.
"We received several calls from the FAA and also from some citizens stating that there was a green laser emanating from a residence pointing at some commercial airliners," said Serge Palanov, spokesman from the Santa Clara Sheriff’s Department. "Our own helicopter — Star One — went up in the air into vicinity and they also experienced this green laser pointing at them."
Small lasers, used commonly as light pointers, can beam a high intensity light over a long distances. If the beam were to strike a pilot’s eyes, it could blind him or her.
It doesn’t matter that "small lasers, commonly used as light pointers" would NOT blind a pilot at the distances involved when some random individual gets lucky enough to scan an airliner by hand or that the description is needlessly alarmist. Trying to hit an aircraft with your laser pointer just isn’t a good idea.
If you know someone who has been doing this, go give them a good smack and take their laser away.