The lasing threshold is the minimum amount of pump energy required for a laser to begin emitting coherent light. It represents the point where the gain from stimulated emission overcomes losses in the laser cavity, enabling sustained laser action.

Lasing Threshold

lasing threshold

pump energy

Coherent light is a type of light in which the waves maintain a constant phase relationship, allowing them to interfere constructively or destructively. This property is essential for applications like lasers, holography, and optical communications, where precise control over light is required.

coherent light

Stimulated emission is a process where an incoming photon induces an excited electron to drop to a lower energy level, emitting a second photon with the same phase, frequency, polarization, and direction as the incoming photon. This principle is fundamental to the operation of lasers, where it leads to the amplification of light.

stimulated emission

A laser cavity, also known as an optical cavity, is a set of mirrors that forms a standing wave cavity resonator for light waves, providing the necessary feedback to sustain laser oscillation. It plays a crucial role in determining the laser's mode structure, frequency stability, and output power by amplifying the light through stimulated emission within the gain medium placed inside the cavity.

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