Facebook Pitches Laser Beams As The High-Speed Internet Of The Future (pcworld.com)

An anonymous reader quotes a report from PCWorld: Facebook says it has developed a laser detector that could open the airwaves to new high-speed data communications systems that don't require dedicated spectrum or licenses. The component, disclosed on Tuesday in a scientific journal, comes from the company's Connectivity Lab, which is involved in developing technology that can help spread high-speed internet to places it currently doesn't reach. At 126 square centimeters, Facebook's new laser detector is thousands of times larger. It consists of plastic optical fibers that have been "doped" so they absorb blue light. The fibers create a large flat area that serves as the detector. They luminesce, so the blue light is reemitted as green light as it travels down the fibers, which are then bundled together tightly before they meet with a photodiode. It's described in a paper published on Tuesday in the journal Optica. Facebook says there are applications for the technology both indoors and outdoors. Around the home, it could be used to transmit high-definition video to mobile devices. Outdoors, the same technology could be used to establish low-cost communications links of a kilometer or more in length. In tests, the company managed to achieve a speed of 2.1Gbps using the detector, and the company thinks it can go faster. By using materials that work closer to infrared, the speed could be increased. And using yet-to-be developed components that work at wavelengths invisible to the human eye, the speed could be increased even more. If invisible to humans, the power could also be increased without danger of harming someone, further increasing speed and distance.

Comments

You instinctively turn away from visible lasers

[raymorris]

Yeah invisible lasers are normally considered MORE dangerous. When even a 5mw visible laser hits your eye, you instinctively turn away immediately. The extremely bright light is uncomfortable. If you can't see it, you don't instinctively turn away. See Chuang LH, Lai CC, Yang KJ, Chen TL, Ku WC (2001). "A traumatic macular hole secondary to a high-energy Nd:YAG laser".

OSHA and other bodies require EXTRA safety measures for invisible or nearly invisible lasers. (Near infrared fiber optic lasers can appear to be a dim red. They are actually very bright, just on the verge on the wavelength humans can see.)

Re:Harm

[Pharmboy]

385nm is invisible to almost all humans, being on the long-ish wavelength of UV, and I wouldn't really say it was very damaging. Everyone likes to jump on the bandwagon like they actually know something about UV when in fact they don't. I've worked with it over 25 years, still do. Out of the millions of products sold, I've never had an injury reported. People do get hurt with UV, but that is exceedingly rare and usually because they didn't follow directions or did something really stupid.

Inside fiber, it is pretty harmless. Most plastics block it (excepting OP4 acrylic), the vast majority of paints absorb it and won't reflect it. It has a smaller wavelength, thus more waves per centimeter, ie: more data. I'm not saying their plan is good or bad, but blanket calling UV dangerous and not workable is ignorant.

Re:Harm

[Khyber]

"385nm is invisible to almost all humans, being on the long-ish wavelength of UV, and I wouldn't really say it was very damaging."

Your research is way out of date. Every LED unit with UV-A I've ever sold was required to have a level 2 JEDEC eye hazard warning.