SAN FRANCISCO -- The Corvis (CORV) - Get Report story, once an alluring mystery, is rapidly becoming an annoying mystery for investors.

Shares of the optical networking gear maker have dropped more than 86% from its post-IPO highs last summer, as concerns ranging from the industry's spending slowdown to the lack of new customers plague the company.

Corvis founder and Chairman David Huber, presenting at the

Robertson Stephens Technology 2001 Conference

Wednesday, was asked more than once why Corvis hasn't been able to add to its original three-company customer list.

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Huber waxed historical, saying time has shown that "attacking into the heart of

Nortel

(NT)

,

Alcatel

(ALA)

and

Lucent's

(LU)

" market has never been a swift process. He would know, having founded and led

Ciena

(CIEN) - Get Report

through its early years. He said carriers typically take six to 18 months to make big strategic equipment decisions, adding that Corvis expects to announce one or two additional customers within the next four months.

Corvis makes optical equipment that enables the transport and switching of laser-generated lightwaves through strands of fiber cables. The company has been extremely tight-lipped about its technology, which once enhanced its reputation, but now seems to contribute more to its illusive value.

Corvis, much like startup rival

Sycamore

(SCMR)

, led the optical bandwagon at a time when investors believed that phone companies would gladly scrap their old electronic gear for new optical fiber-based equipment. That revolution

hasn't materialized as quickly as expected, putting pressure on the stocks of Corvis and Sycamore. Corvis is trading at about $16.56, well off its 52-week high of $114.75.

Of course, another negative factor has been Wall Street's flight from these blue-sky optical opportunities as the phone and Net service providers shift from spending to conserving cash and making payments on their heavy debts.

Though it had no revenue, Corvis made a

stellar public debut in July, in part because it was able to point to customers that had agreed to try the equipment. Two of those customers --

Broadwing

(BRW)

and

Williams Communications

(WCG) - Get Report

-- were also granted sweet pre-IPO Corvis stock deals for their support.

Qwest

(Q)

is the other Corvis customer and is also an investor.

The Street has tended to discount the value of those initial customers and has hoped to see more names added to the list.

The fact that Corvis hasn't seen an even sharper drop in its stock is a fairly modest testament to the company's story. If its claims hold true, Corvis is a phenomenally compelling tale of greater fiber switching capacity and coast-to-coast transport capabilities. This bigger and farther claim, according to Huber, means easier and cheaper operation because it requires fewer, if any, costly regeneration devices to juice up the laser signal over distances as great as 6,000 kilometers.

Huber said he expects Broadwing will launch its Corvis-powered daisy-chain structured network in the next few weeks. Once customers see how quickly Broadwing's network can set up capacity-on-demand, "it will be an effective selling tool for us," he said.

Two money managers who saw the Corvis presentation admitted to be awed by the slide show and the technology's promise. But were they going to buy the stock? Both said no, because they're waiting for proof of the story in the form of new customers.