What is the process called where a newly created photon acquires energy equal to the photons that created it?

The process where a newly created photon acquires energy equal to the photons that created it is known as stimulated emission. In this phenomenon, an incoming photon of a specific wavelength interacts with an excited electron in a material, causing the electron to drop to a lower energy state and emit a second photon. This emitted photon has the same energy, phase, frequency, and direction as the stimulating photon, resulting in a coherent light source.

Stimulated emission is a crucial mechanism in laser operation, enabling the amplification of light as multiple photons stimulate the release of additional photons from excited atoms or molecules. This leads to the production of a highly intense and focused beam of light.

Other processes mentioned, such as spontaneous emission, refer to the natural process where atoms or molecules lose energy and emit photons without external stimulation, resulting in photons that are not coherent or synchronized. Photon resonance describes interactions where photons can cause energy levels in atoms to shift, and quantum emission generally pertains to a broader context of light emission by quantum systems but does not specifically address the process of photon amplification as effectively as stimulated emission does.