Which of the following best describes how laser radiation spreads?

The spreading of laser radiation can best be characterized by a decrease in intensity over distance. As laser light travels, it often begins to diverge slightly beyond the aperture from which it is emitted. This divergence leads to a gradual reduction in intensity as the distance from the laser source increases. While some lasers are designed to minimize divergence and maintain beam quality over longer distances, general behavior includes a diminishment of intensity with distance.

Other options suggest uniform and constant behavior or an increase in intensity, which does not accurately reflect how laser radiation behaves in real-world scenarios. While some lasers may appear to have a coherent beam at short distances, as the beam travels further, the intensity typically decreases due to spreading and atmospheric absorption or scattering factors. Thus, the best description of how laser radiation spreads is that it diminishes significantly beyond a short distance.