Back home on earth, a related approach to provisioning point-to-point networking using “fiberless photonics” is being rebooted. The first commercial attempts at terrestrial free-space optical communications were attempted in the late-1990s photonics boom, driven by innovators like Terabeam, Optical Crossing, AirFiber, and Lucent’s OpticAir. Unfortunately, these enterprises suffered the same fate as so many others when the photonics boom—driven as it was at the time by the single application of long-haul telecom—entered a deep slumber after capacity needs had been met for the foreseeable future by the laying of “dark fiber” for eventual provisioning. Those days are past. The industry awakened to exponentiating demand for data driven by a host of applications from social networks to streaming media, personal medicine to the Internet of Things, Industry 4.0 to autonomous vehicles.
Despite the temporary harrowing of the industry in the decade following 2002, the principle behind free-space optical communications remained sound, and it is fundamentally similar to optical telegraphy dating to the 18th century7 (though of course much faster): messages are encoded in blinks of light conveyed from one terrestrial location to another. This presents the potential for rapidly provisioning secure, dedicated photonic interconnects between locations, such as from building to building in a crowded city, or for the “last mile” of a broader network.
Twenty years ago, these interconnects required substantially expanded beams—telescopes, typically on the order of 200mm aperture—both for fault-tolerance against the occasional bird breaking the beam and for eye-safety. Today, a new wave of innovators is leveraging this era’s more advanced error-correction algorithms and more-efficient electronics to allow lower-cost yet higher-speed implementations. Transcelestial of Singapore is an example, offering compact, pole-mounted transceivers with up to 10GBps throughput.