Lasers are all around us, being used for a vast variety of purposes, some of which are really surprising. These coherent beams of light have found uses in the military, in industry, in the latest audio-visual technology, and even in medicine.
Let’s have a look at some of the most surprising uses:
1. Airborne Lasers
There are planes being tested that include laser cannons. Long a favorite of sci-fi writers and
films, it seems that the military has long believed that lasers could find a use as weapons. Since the Reagan era, billions of dollars has been poured into projects to make effective use of lasers as battlefield weapons.
One of the problems with using lasers like this is that they are big, and heavy. And so, the planes needed to carry them are also extremely large. The most successful project, in fact, has been a laser mounted inside a Boeing 747-400.
2. Really Fast Microscopes
Lasers have long found use in medical settings, and the latest applications are really amazing. Developed by engineers at UCLA, STEAM – serial time-encoded amplified microscopy – is a way of using laser light to see inside cells.
Without getting too deep into the technical details, the system essentially shines micro-pulses of laser light through the cell which is being observed, and this light is then received by a very high speed single pixel photodetector. The system is incredibly fast, achieving speeds of up to 36.7 million frames a second, and may well revolutionize the way that cancer cells are understood.
3. Blu-Ray Discs
A great example of lasers much closer to home, Blu-ray discs are now becoming more and more popular. Originally used for games and other purposes which required enormous amounts of data to be stored on a single disc, now most movies are released on this format.
CDs, DVDs, and Blu-ray discs all use lasers, of course. In all of these formats, a laser is reflected from the shiny surface of the optical disc. A series of pits, so small they are invisible to the unaided eye, means that the laser light is absorbed or reflected. This is turned into binary data inside the device being used to read the disc, and this series of 1s and 0s is then converted into images or sound.
The difference with Blu-ray player is that the wavelength of the laser light, at 405 nm, is significantly smaller than that of a DVD, at 650 nm. This allows more information to be encoded in a smaller space.
4. Teeth Whitening
Yes, teeth whitening. Whilst it may sound scary, laser teeth whitening has gained traction as a popular choice over traditional whitening kits. Laser teeth whitening is a bit of a misnomer, because in most procedures it is not in fact the laser that whitens your teeth – instead, the light produced merely speeds up the reaction of the hydrogen peroxide that is commonly use to whiten teeth.
In these applications, the laser used is typically blue, as this has been found to be the most effective color of light to catalyze the reaction, and get teeth whiter faster. And whilst it may sound dangerous to have a powerful laser in your mouth, nowadays the lasers used for these purposes are designed so that they do not give out any harmful wavelengths of light.