Is a true laser beam an example of stimulated emission of radiation?

A true laser beam is indeed an example of stimulated emission of radiation. In a laser, the process begins with the excitation of atoms or molecules within a gain medium, which can be a gas, liquid, or solid. When these excited atoms return to their ground state, they can emit photons.

However, in the case of lasers, the emitted photons can cause other excited atoms to emit more photons in a cascading effect known as stimulated emission. This is the key process that distinguishes lasers from ordinary light sources. The result is a coherent beam of light, where the emitted photons are of the same wavelength, phase, and direction.

This coherence is what gives laser beams their unique properties, such as focused intensity and precision, which are essential in various applications ranging from medical procedures to industrial cutting and scientific research. Thus, the characterization of a true laser beam as resulting from stimulated emission of radiation is correct.