Ask HN: Can directed energy weapons be rendered impotent using mirrors?

No.

a) The mirror would need to be continuous. No gaps.

b) The mirror would have to be perfect. No dirt. No smudges.

Ref: https://www.quora.com/Will-a-laser-burn-through-a-mirror

Freshman physics was too long ago. Are there wavelength effects on how the mirror reflects, or is there thermal or shock limitations from the impact of the photon stream? As I recall, clouds of small particulates (phosphorus smoke?) screw up lower-power lasers but it's possible it can blow/burn a hole through at higher E?

Remember, photons have momentum proportional to frequency. So a whole lot of them at higher frequency might blow a "protected drone" away by force not by optics?

Directed energy weapons don't exclusively exist in the visible light spectrum, as far as I know. Reflecting the stuff you can see only protects you against the least-harmful effects of the weapon.