Semiconductor technologies are pushing the evolution of optical communications, notes Gartner in a report on the technological opportunities that will arise from optics-based networking. Gartner segments the different applications of the technology into three classes of components.
Communications networking
The first class is active and passive optical components. Active optical components deal with the conversion between light and electricity, and include things such as lasers and photodetectors. Passive optical components include filters, attenuators, and switches -- things that operate exclusively on light.
The second class is optoelectronic components. These operate exclusively on electrical signals, but perform physical layer functions specific to optical networking.
Finally, amplifiers and fiber-optic modules are created with combinations of the first two component classes. Fiber-optic modules include lasers and laser drivers on the transmit path and photodetectors and transimpedance amplifiers on the receive path. Amplifiers are bigger subsystems made up of various passive and active optical components.
Storage area networking
Fiber optics are also being used to connect servers and storage devices. According to Gartner, these optical storage area networks (SANs) offer certain advantages over server-based storage, such as higher data availability, better fault tolerance, reduced total cost of ownership, and better scalability. For these reasons, Fibre Channel is the technology standard of choice for SANs. The Fibre Channel standard enables transmission over both copper and fiber cabling, but demand for long-distance SANs and higher data rates make fiber optics a better option.
Free-space (wireless) optics
Free-space optics technology involves beaming optical lasers through the air. It is used in short to midrange optical links in metropolitan networks or on the edge of the access network. This technique can move data at 10Gbps between links, and therefore helps to alleviate the so called "last mile" bandwidth bottleneck that many networks experience. Free-space optics were originally used in government and scientific projects, although it is also a valid option in urban areas where installing new fiber would be too expensive.
Where it's going
As Gartner explains, the main inhibitor of communications evolution has been insufficient access to bandwidth in the network core. However, optical communications technology has solved this problem. The industry is now focusing on the last mile of the network, and fiber-based and free-space technologies should open bandwidth there as well.
There will be challenges, of course. Gartner notes that although fiber-based technologies have passed most technology and regulatory obstacles, the sheer number of system and component suppliers is threatening profitability. However, the market should stabilized as prices drop, vendors leave, and users adopt the technology.
Free-space optics still face technology and reliability problems. Gartner suggests that the perception of this technology among carriers could improve through a united effort by free-space optics vendors.