As a medium for telecommunications, fiber optics is much faster than conventional wire, because it uses light instead of electricity to send information.
One emerging technology in this sector has been Fiber-to-the-Home (FTTH), also called Fiber-to-the-Premises (FTTP) or Fiber-to-the-Building (FTTB). FTTH brings fiber optics directly to homes/buildings, while a similar technology, fiber-to-the-node (FTTN), brings the fiber optics to a community and then connects the fiber optics to the homes with a traditional copper cable. In the past, consumer telecom networks had a high-speed backbone with lower speed cables running to users' homes and offices. The high-speed backbones were able to carry the combined capacity of all the users, but the infrastructure running to the users severely limited the speed and bandwidth available to consumers. FTTH allows for much larger bandwidth and much faster delivery speeds, which are essential for modern "triple-play" deliveries in which access providers offer video, data, and telephony services. It also requires the installation of new transmission, wiring, and receiving infrastructure.
Currently, two major service providers are rolling out FTTH fiber optic access plans: AT&T, with U-verse, Verizon, with FiOS, while Comcast is rolling out a competing technology called Docsis 3.0. Consumers are increasingly streaming and downloading large files, like movies, and engaging in video-chatting, using the small cameras that are attached to many new laptops. Both AT&T and Verizon offer "high-speed" connections of speeds up to 10 Mbps - but with the demand that services like video-chatting and streaming video put on networks, the 50 MBPS offered by Docsis 3.0 and FiOS look far more appealing. As a comparison, DSL has a speed of 1.5 Mbps. The telecom giants jumping on the FTTH bandwagon signals that fiber optics is set to go mainstream, and demand for fiber optics infrastructure will grow. It's likely that larger telecom infrastructure companies like Alcatel and Tellabs will receive most of the fiber optics business, but smaller firms like Emcore could also get in the game.
AT&T: U-Verse maxes out at 18 Mbps, but is cheaper than Comcast and FiOS (excluding New York) at only $100/month. U-Verse uses both FTTH and FTTN technology, depending on the area. The FTTN model is faster and cheaper to deploy than FTTH, but the copper connections to the homes sacrifices speed compared to FTTH. U-Verse is currently in parts of California, Connecticut, Georgia, Indiana, Illinois, Missouri, Michigan, Ohio, Oklahoma, Texas, and Wisconsin. AT&T plans to service 1 million homes by 2008 and 30 million homes by 2010. 
Verizon: Verizon FiOS is the largest fiber optic network in the US. FiOS offers a downstream speed of 50 Mbps and costs $90/month in New York, but $140/month in Massacheusetts, Rhode Island, Connecticut, New Jersey, and Florida. To give an idea of how fast 50 mbps really is, at 50 mbps an HD movie can be downloaded in 13 minutes and a 60 minute video can be downloaded in a mere 8 seconds. In the 16 states that Verizon plans on introducing its FiOS system, the company reported that it expects to spend close to $23 billion from 2004 to 2010 in network installation.  Verizon is dominating FTTH as it is responsible for over 70% of the FTTH connections in the US.  By the end of 2007, FiOS had 9.3 million customers and Verizon expects to have 12 million customers by the end of 2008. aldobai.com
Given the size and breadth of telecom equipment offerings from Alcatel (ALU) and Tellabs (TLAB) it is likely these two will get the bulk of the fiber business. However, the following are some smaller companies with infrastructure offerings as well:
EMCORE (EMKR) has a wide offering of fiber optics products and could possibly become a notable player as fiber optics continue to grow.
AFL Telecommunications provides fiber optic products and services to the telecommunications industry. They are completely tied to the success of fiber optics in this industry. AFL is part of Fujikura (TYO:5803).
Corning makes optical fibers for the cables. Corning made an important development when they created a bendable fiber in 2007 which is specifically vital for the fiber optics used in New York due the tight requirements of many of its older buildings.
ADC Telecommunications provides fiber optic infrastructure products and services.
The greatest rate of FTTH/FTTB adoption is occuring in Asia. About 21% of homes in Hong Kong have FTTH and South Korea has 19.6% of homes connected to FTTH. The main reason for the huge penetration in Asia, as opposed to the US, is that the governments of countries such as Japan and South Korea are specifically promoting this technology as a part of their national strategy.
The United states had about a 1.3% penetration in 2007, but does have a large amount of fiber optic cables in the ground left unused from the dot com bust. Many of the telecom companies were laying cable at a faster rate than they were getting customers, but now these companies can start utilizing this installed base thanks to the renewed growth of demand from consumers. In 2007, the number of US households with FTTH doubled from 2006. The major proponent of FTTH is Verizon. Verizon is responsible for about 70% of the households passed by fiber optic networks and added about 203,000 customers to their FiOS service in 2nd quarter of 2007 alone.