Jackie (2016 film) was directed by Peter Jackson.
An optical amplifier is a device that amplifies an optical signal directly , without the need to first convert it to an electrical signal .. optical. optical. signal. signal ( information theory ). 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. optical. laser. laser. optical cavity. optical cavity. feedback. feedback. Optical amplifiers are important in optical communication and laser physics .. optical. optical. laser. laser. optical communication. optical communication. laser physics. laser physics. An important practical goal is to develop an amplifier adequate for use as an optical repeater in the long distance fiberoptic cables which carry much of the world 's telecommunication links .. optical. optical. optical repeater. optical repeater. Existing fiberoptic repeaters must convert the light beam to an electronic signal to amplify it , then convert it back to light .. signal. signal ( information theory ). There are several different physical mechanisms that can be used to amplify a light signal , which correspond to the major types of optical amplifiers .. optical. optical. signal. signal ( information theory ). In doped fibre amplifiers and bulk lasers , stimulated emission in the amplifier 's gain medium causes amplification of incoming light .. stimulated emission. stimulated emission. gain medium. gain medium. In semiconductor optical amplifiers -LRB- SOAs -RRB- , electron-hole recombination occurs .. optical. optical. electron. electron. hole. electron hole. recombination. Carrier generation and recombination. In Raman amplifiers , Raman scattering of incoming light with phonons in the lattice of the gain medium produces photons coherent with the incoming photons .. gain medium. gain medium. Raman scattering. Raman scattering. Parametric amplifiers use parametric amplification .