Which statement about beam collimation is most accurate?

• A. Collimated beams have zero divergence.
• B. Collimated beams require very high energy to be produced.
• C. Collimated beams are defined by a constant beam width.
• D. Beam Divergence is minimized to produce a collimated beam.

Answer: (D)

Collimation aims to make the rays travel in nearly the same direction by minimizing the beam’s angular spread, or divergence. In practice you can’t achieve perfectly zero divergence because diffraction and optical imperfections always introduce some spread, but the goal is to reduce divergence so the beam is as parallel as possible. This is why the statement about minimizing beam divergence to produce a collimated beam is the most accurate. Energy level doesn’t define collimation—the same concept applies across a range of energies with the right optics. And a constant beam width isn’t the defining feature, since the width can change due to diffraction and focusing elements even when divergence is minimized.