Both Intel and Cisco invested in Bookham and the company built two wafer fabs for silicon photonics with automated back-end assembly.
Although Bookham grew by supplying such things as wavelength division multiplexing (WDM) components it was also obvious to Rickman that silicon doesn't easily make light and is missing several other electro-optic properties. "We can make wave guides but light generation and detection are difficult. Nonetheless silicon photonics remains compelling."
"To begin it was not communications but sensors I was interested in. But in the late 1990s the concentration was on optical fiber communications and the dot-com boom. The sensors were ahead of their time." By this time Bookham WDMs and tunable filters were designed in with the big networking and telecommunications companies of their day, Nortel and Lucent, Rickman recalls.
But after the boom came the bust and this had a negative effect on Bookham, which had grown by acquisition into a much broader optical components company that was no longer only focused on silicon photonics. Indeed, Bookham ended up licensing some of its optical intellectual property to a California company called Kotura to help sort out IP issues after Kotura started supplying variable optical attenuators (VOAs) similar to Bookham's.
Kotura had been founded in 2004 and Rickman ended up joining that company as chairman. In a sense he transferred along with the IP he had helped to create. Kotura is now part of Mellanox Technologies Ltd., which in turn is due to be acquired by Nvidia Inc.
"First generation silicon photonics components were aimed at telecom. Second generation products were able to make more use of germanium, in silicon-germanium, and monolithic detectors. It accompanied the increased use of optical transceivers in data centers. Single-mode optical fibre also moved into data centers. There were far more optical ports in data centers than in telecommunications."
Rickman pointed out that meanwhile the silicon photonics sector was benefitting from a virtuous cycle with increasing application volumes and the arrival of the option of foundry production. Economies of scale in manufacture in turn reduces component costs and opens up yet more higher volume applications that are cost-sensitive.
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