What is the ability of the laser to minimize beam divergence (spread) over a given distance?

• A. The beam does not spread much as it travels, i.e., low divergence.
• B. The beam spreads rapidly over distance.
• C. The beam is never focused.
• D. The beam changes color over distance.

Answer: (A)

Divergence describes how much a laser beam spreads as it travels. When a beam is well-collimated, the rays are almost parallel, so the beam diameter stays nearly constant over distance. This minimal spread is what we mean by low divergence—the laser keeps its energy concentrated rather than fanning out. The ability to minimize divergence depends on beam quality and aperture: a larger initial beam size and good optics reduce the divergence angle, so the beam travels farther without expanding much (roughly tied to factors like wavelength and how tightly the beam is focused at the exit). The other ideas—rapid spreading, never being focused, or changing color—don’t address how the beam maintains its size during propagation.