Optical networking
Because it is capable of achieving extremely high bandwidth, it is an enabling technology for the Internet and telecommunication networks that transmit the vast majority of all human and machine-to-machine information.In 1964, Charles Kao showed that to transmit data for long distances, a glass fiber would need loss no greater than 20 dB per kilometer.A breakthrough came in 1970, when Donald B. Keck, Robert D. Maurer, and Peter C. Schultz of Corning Incorporated designed a glass fiber, made of fused silica, with a loss of only 16 dB/km.During signal regeneration, slight discrepancies in various frequencies introduced an intolerable level of noise, making WDM with greater than 4 channels impractical for high-capacity fiber communications.[10] [11] Ciena developed the dual-stage optical amplifier capable of transmitting data at uniform gain on multiple wavelengths, and with that, in June 1996, introduced the first commercial dense WDM system.[18] In 2018, Telstra of Australia deployed a live system that enables the transmission of 30.4 Tbit/s per fiber pair over 61.5 GHz spectrum, equal to 1.2 million 4K Ultra HD videos being streamed simultaneously.[19] As a result of this ability to transport large traffic volumes, WDM has become the common basis of nearly every global communication network and thus, a foundation of the Internet today.[20] [21] Demand for bandwidth is driven primarily by Internet Protocol (IP) traffic from video services, telemedicine, social networking, mobile phone use and cloud-based computing.