This optical amplification is started from a certain emission but it is not yet exposed until Albert Einstein proposed it in 1916. After that, things became more serious after 1954 when Townes and Arthur Schawlow also with Gordon Gould proposed laser action, then shortly after 4 years, in 1960, the first laser was built by Theodore Maiman. Furthermore, Gordon also derived the word laser from “the amplification of light by the stimulated emission of radiation”. Amplifying the look of the laser developer is a very important step in building a laser, which is why these people take a step forward to develop amplifiers from solid-state lasers for use as sources of light. This is because semiconductors have high gain. The laser composed of high gain and low noise is classified as the best laser.Diagram 1: The general shape of an optical amplifierThe main type of optical amplifier consists of three types: semi-automatic optical amplifier -conductor (SOA), the Raman optical amplifier and the rear optical amplifier. Ground Doped Fiber Amplifier (EDFA). Semiconductor optical amplifier (SOA) is a type of optical amplifier pumped by electrical currents. So this optical amplifier only handles less power and produces more noise than the rear ground doped fiber amplifier (EDFA). It is also less expensive and suitable for local use. This type also uses a semiconductor to provide gain support. The solid-state optical amplifier also provides relatively low gain and high noise figure. Diagram 2: Semiconductor optical amplifier The Raman optical amplifier has been demonstrated since the early 1970s by Stolen and Ippen. But, in the early 2000s, this type of optical amplifier is widely used and measures almost 300 to 800 km and even reaches more than 800 km in length in optical fiber transmission systems. Due to the advancements in...... middle of paper ......Division Multiplexing, is a device that will be used as a fiber optic system because it can have one or more input and output fibers. Additionally, optical isolator is also used to allow light to flow in one direction and to prevent unwanted feedback. The pump also used in optical amplifier. The most commonly used pump is 980 nm and 1480 nm. For 980 nm, it produces high gain and low noise and also provides low ASE (amplified spontaneous emission), which is the noise floor when the spontaneous emission is also amplified as the light travels toward the amplifying medium. The basic principle used in this optical amplifier is the spontaneous emission and the stimulated emission. Light will be absorbed as it travels. Light will be amplified as it travels through the medium, where the population of light is much larger in higher energy states than in lower energy states..