What is stimulated emission in laser optics?

Stimulated emission is a process in laser optics where an incoming photon interacts with an excited electron in an atom or molecule, causing it to drop to a lower energy state and release a second photon. This emitted photon has the same energy, phase, and direction as the incoming photon, leading to a coherent and amplified beam of light. This principle is fundamental to the operation of lasers, allowing for the generation of intense and focused light beams.