Amplified Spontaneous Emission (ASE) is a phenomenon in optical systems where spontaneously emitted photons are amplified as they pass through a gain medium, such as an optical fiber or laser material. Unlike laser emission, ASE occurs without optical feedback or resonant cavity, resulting in a broad, incoherent light output. In cybersecurity, ASE is relevant to optical communication security because it can introduce noise, degrade signal quality, and potentially leak information through side channels. Understanding and mitigating ASE is important for maintaining the integrity and confidentiality of data transmitted over fiber-optic networks.