Anyone who's ever played with a laser pointer understands its ability to be used in Morse code operations from pretty impressive distances. Anyone who's ever read about a pilot forced to land a plane or change course because a laser was shone into the cabin understands a laser's range. A new plan from Facebook (News - Alert)'s engineers, discussed in detail in the journal Optica, combines these two points to deliver a novel new concept in Internet access: using laser beams to deliver access to areas once considered too remote for anything but satellite and at staggering speeds.
Laser beams are an attractive media thanks to the range available, the ability to hold a lot of information, and the ability to operate without requiring dedicated spectrum. This along with the sheer versatility of being able to set up data links in areas not on the standard grid. However, there are some problems to using lasers.
The biggest challenge is a combination of two factors: the detectors required to run such a system must be very small, and any beam of light tends to widen as it travels through space. The latter means that the beam can eventually be larger than the detector, and by a fairly wide margin. The light can be focused back down to the proper size with the right optics, but that's an expensive process. Facebook's engineers, meanwhile, seem to have developed a workaround that fixes this.
By using fluorescent materials instead of optics, using organic dye molecules that can absorb blue light and essentially turn it into green light coming out, the new green light can be transferred to a photodetector, letting the fibers serve as a kind of relay to the closer photodetector. As a result, Facebook's engineers are not only achieving speeds of 2.1 gigabits per second, but believe that can be boosted still further if the fibers could absorb infrared light instead of blue.
Some question the impact of clouds and weather on such a product, but considering the bigger picture—where satellite Internet goes down whenever someone so much as looks at the dish funny—this will likely be a relief to rural residents and similar underserved populations that haven't had many options.
In addition, it is hard to imagine someone putting a bandwidth cap on a service like this. And, if it ever becomes possible to get multi-gigabit Internet access to just about anywhere that can generate a line-of-sight connection somehow—up to and including putting the receiver on a big pole—it's going to be a game-changer.
Internet access has sometimes been tough to come by even in the United States, and developments like this may be just the thing to get everyone online relatively inexpensively. It is certainly an interesting technology to keep up on.
