A semiconductor optical amplifier is a type of optical amplifier, a device that amplifies optical signals, which can be used to increase data transmission power and extend transmission distance. Semiconductor optical amplifiers use semiconductor materials as gain media, which can amplify the power of small signal light without significantly reducing other optical indicators. They can be used as preamplifiers, wavelength converters, high-speed optical shutters, etc., and are widely used in optical communication transmission systems and optical fibers sensing system.
A semiconductor optical amplifier (SOA) consists of an active region and a passive region, and the active region is the gain region. When the light signal passes through the active region, it causes these electrons to lose energy in the form of photons and return to the ground state. The excited photons have the same wavelength as the optical signal, thereby amplifying the optical signal. A semiconductor optical amplifier is a semiconductor element that amplifies light. Anti-reflection treatment is applied on both sides of the semiconductor laser to eliminate the resonator structure. When light enters from outside the semiconductor, the light is amplified by stimulated emission.
The working principle of the semiconductor optical amplifier is that the semiconductor carriers are converted into inverted particles by the driving current, so that the amplitude of the injected seed light is amplified, and the basic physical properties such as polarization, line width and frequency of the injected seed light are maintained. With the increase of the working current, the output optical power also increases as a certain function. At present, the most common and mature technologies are straight-waveguide semiconductor optical amplifiers and wide-waveguide semiconductor optical amplifiers.
The structure is simple, the volume is small, the existing semiconductor laser technology can be fully utilized, the manufacturing process is mature, the cost is low, the life is long, the power consumption is low, and it is easy to integrate with other optical devices. In addition, its working band can cover the 1.3-1.6/μm band, which cannot be achieved by EDFA or PDFA. In addition to being used for optical amplification, soa optical amplifiers can also be used as optical switches and wavelength converters.