OA Transmitter Subsystems (OATs): An OAT integrates a power amplifier with an optical transmitter, resulting in a higher power transmitter. Amplifies optical signals over C-band wavelengths in the range from 1535 nm to 1547 nm. Adjusts the gain. These categories, as defined in ITU-T G. Power Amplifiers (PAs): Positioned after the optical transmitter, PAs boost the signal power. Optical amplifiers are used to create laser guide stars which provide feedback to the adaptive optics control systems which dynamically adjust the shape of the mirrors in the largest astronomical telescopes. In this article, we will provide a more detailed introduction to the SOA in the hope that it will help you understand this device.