Optical Transmission and Amplification Devices

An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. Optical amplifiers are important in optical communication and laser physics. They are used as optical repeaters in the long distance fiber-optic cabl. HistoryThe principle of optical amplification was invented by on November 13, 1957. He filed US Patent US80453959A on April 6, 1959, titled "Light Amplifiers Employing Collisions to Produce Population Inversions". Almost any laser can be to produce for light at the wavelength of a laser made with the same material as its gain medium. Such amplifiers are commonly used to produce high power. Semiconductor optical amplifiers (SOAs) are amplifiers which use a semiconductor to provide the gain medium. These amplifiers have a similar structure to but with anti-reflection d. [PDF]