After a decade of building broadband networks in the sky, AOptix Technologies has returned to commercial telecoms on Earth.

The Bay Area firm is eyeing Asia-Pacific markets in particular for its high-end wireless backhaul, which it's pitching as an alternative to fiber.

AOptix Technologies began life at the peak of the telecom bubble in 2000, when "free-space optics" plays had a mini-boom of their own: In 2002, the company raised $18 million in a finance round led by Lehman Brothers. (See AOptix Gets $18M.)

After the bubble burst, it turned its attention to the defense sector, and during the past dozen years has built a business offering up to 80Gbit/s air-to-air and air-to-ground links for the Defense Advanced Research Projects Agency (DARPA) and the US Air Force.

As chairman and CEO Dean Senner describes it, AOptix gear enables a jet travelling at Mach 0.8 to hit a four-inch target on another jet more than 200km away with an infra-red laser.

He says the mobile data revolution has drawn AOptix back to commercial telecom. In November 2013 it launched its Intellimax product line, which promises multi-gigabit speeds with five-9s reliability in the 70-80GHz range, for telcos and enterprises.

Senner says that by combining both optical and millimeter wave, it avoids the effects, respectively, of fog and rain fade that degrade those technologies when deployed separately.

"We look at it clearly as an alternative to fiber," Senner says. "If you have an application where microwave or milliwave can do the job, then you should use that technology. It will be cheaper."

As to just how much cheaper than fiber, AOptix doesn't have a clear answer on that yet.

In an emailed response to questions, an AOptix spokesperson stated: "As you can imagine, comparison figures, even percentages, get muddy because they differ when we're comparing the price wireless fiber to the costs of dark fiber, lit fiber and laying new fiber."

The Intellimax solution is being tested as a backhaul technology in field trials with three Tier 1 carriers, according to AOptix.

Besides backhaul, it is also being offered to enterprises for last-mile access where fiber isn't available.

AOptix isn't the only vendor still touting free-space optics, though, despite its reputation as a technology that promises more than it can deliver. LightPointe Communications Inc. , fSona Communications Corp. , and Skyfiber are just some of the other names still in the market. (See fSona Deploys in Lebanon and LightPointe Goes Down Under.)

— Robert Clark, contributing editor, special to Light Reading