The pump lamp gives Nd.YAG crystal a broadband continuum of light energy. The absorption region of Nd:YAG is 0.730μm ~ 0.760μm and 0.790μm ~ 0.820μm. After the spectrum energy is absorbed, the atom will be from low energy level to high energy.
Level transitions, some of which transition to high-energy atoms will transition to lower energy levels and release the same frequency monochromatic spectrum.
When the activator is placed in two mutually parallel mirrors (one of which is 100% reflective of the other 50% of the mirror), an optical cavity can be constructed in which the non-axially propagated monochromatic spectrum Out of the cavity: The monochromatic spectrum propagating in the axial direction propagates back and forth in the cavity.
When the monochromatic spectrum propagates back and forth in the laser material, it is called “self-oscillation” in the cavity. When the pump lamp provides enough high-energy atoms in the laser material, the high-energy atoms have spontaneous emission transitions, stimulated emission transitions, and stimulated absorption transitions between the two levels.
The stimulated emission light generated by the stimulated emission transition has the same frequency and phase as the incident light. When the light repeats the “active matter inversion state” activation substance in the cavity, the intensity of the monochromatic spectrum of the same frequency is increased to generate a laser.
Post time: Jul-01-2022