What is the source of photon energy found in the center of a laser?

What is the source of photon energy found in the center of a laser?

• A. Pump source
• B. Cavity
• C. Active Medium
• D. Ground State

Answer: (C)

Photon energy in a laser is produced by stimulated emission inside the active medium. The active medium contains atoms or molecules with a specific energy-level spacing that defines the laser’s photon energy. When an excited particle encounters a photon of the right energy, it is stimulated to emit another photon that matches the first in energy, phase, and direction, and this process amplifies light within the medium. The energy of those photons comes from the energy stored in the excited states of the active medium, established by the pump process that creates population inversion. The cavity helps by reflecting light to build up intensity, but it does not supply the photon energy itself. The ground state is simply the lower energy level involved in the transition.

Photon energy in a laser is produced by stimulated emission inside the active medium. The active medium contains atoms or molecules with a specific energy-level spacing that defines the laser’s photon energy. When an excited particle encounters a photon of the right energy, it is stimulated to emit another photon that matches the first in energy, phase, and direction, and this process amplifies light within the medium. The energy of those photons comes from the energy stored in the excited states of the active medium, established by the pump process that creates population inversion. The cavity helps by reflecting light to build up intensity, but it does not supply the photon energy itself. The ground state is simply the lower energy level involved in the transition.