Kao, Charles

While engineers at Standard Telecommunications Laboratories, an ITT subsidiary, Charles

Kao and George Hockham achieved the first conceptual breakthrough in the development of fiber optic transmission systems (FOTS). In 1966, Kao and Hockham determined that optical fibers of fused silica could satisfy signal attenuation requirements by overcoming issues of absorption, diffusion, and bending loss. At the time, attenuation of 20 dB per kilometer was considered satisfactory for a commercially viable system.

Contemporary FOTS are designed around attenuation levels in the range of 1.5–3.0 db per kilometer, or so, depending on the specific type of fiber and the wavelength employed. See also FOTS and optical fiber.

• LOH (Line OverHead)
• long distance
• long haul circuit
• longitudinal redundancy checking (LRC)
• long wavelength band (L-Band)
• long wavelength (LW)
• loop
• loop
• loopback address
• loopback address
• loopback test
• loop current
• loop start
• loose-tube cable
• LOS (Line-of-Sight)
• loss
• loss budget
• lossless compression
• lossy compression
• low delay code excited linear prediction (LD-CELP)
• low earth orbit (LEO)
• low frequency (LF)
• Low Income Consumers Program
• low-order mode
• low-pass filter