Which laser term describes the region where photons are amplified by stimulated emission?

Which laser term describes the region where photons are amplified by stimulated emission?

• A. Pump source
• B. Cavity
• C. Active Medium
• D. Output Coupler

Answer: (C)

The active medium is where light gets amplified through stimulated emission. In this region, atoms or molecules are kept in a higher energy state (population inversion) by the pump source. As a photon travels through the gain medium, it can stimulate those excited states to emit additional photons that match the original in energy, phase, and direction. Each stimulated emission event adds photons to the beam, causing the light to amplify as it passes through the medium. The pump source provides the energy to maintain the inversion, while the cavity helps by feeding photons back through the gain region to boost amplification, and the output coupler releases part of the light as the laser output.

The active medium is where light gets amplified through stimulated emission. In this region, atoms or molecules are kept in a higher energy state (population inversion) by the pump source. As a photon travels through the gain medium, it can stimulate those excited states to emit additional photons that match the original in energy, phase, and direction. Each stimulated emission event adds photons to the beam, causing the light to amplify as it passes through the medium. The pump source provides the energy to maintain the inversion, while the cavity helps by feeding photons back through the gain region to boost amplification, and the output coupler releases part of the light as the laser output.