Who is credited with theorizing stimulated emission?

The concept of stimulated emission is primarily attributed to Albert Einstein. He introduced the idea in a paper published in 1917, where he described the process through which an incoming photon can stimulate an excited atom to emit a second photon, effectively amplifying light. This theoretical underpinning laid the groundwork for the development of lasers, which rely on stimulated emission as a fundamental mechanism.

While other scientists like Niels Bohr contributed significantly to quantum theory and atomic structure, and Max Planck is known for his foundational work on quantum mechanics and the quantization of energy, it was Einstein who specifically articulated the principles of stimulated emission. Erwin Schrödinger is noted for his contributions to quantum mechanics, particularly the Schrödinger equation, but not specifically for the theory of stimulated emission.