Combat lasers (30-60kw) heats the inside of an incoming mortar round and cause it to explode mid-air. Mortar rounds are moving at hundreds of miles per hour. Lasers pierce the outer skin of a drone, taking out key circuits and making it crash. There is a Lockheed video where the laser heats the rear control fin of a drone and sets it on fire. The US will be testing a 150 kilowatt laser next year.
ICBMs (Intercontinental Ballastic Missiles) and other rockets can be made to spin (rotate) so that the laser heating would be spread around the missile instead of lingering on one spot. This would double or triple the power or the time needed to take out the missile.
Dielectric mirrors can be 99.99+% reflective to particular wavelengths. Multiple coatings proof each working against a different range of wavelengths could be applied.
The US Air force has funded dielectric reflector particles (1-20 microns). The Lunas Corp dielectric reflector particles will be a first-of-a kind demonstration of dielectric mirror technology in an easily processable form. The implication for thermal management and laser-based technologies is greatly reduced costs. Dielectric mirror technology is now only produced on small flat parts using vapor phase technology. Dielectric reflector particles will allow selective filtering of infrared radiation using easily applied paints and clear coats.
Ablative materials can absorb laser energy and use it to transform into a gas. The laser strike would hit the ablative material and vaporize it, without dealing serious damage to the target underneath.
Counter lasers to confuse targeting
There are also counter lasers that can be used to confuse the targeting of an attacking laser.
How long does it take to destroy the target
Higher power lasers will be able to destroy targets more quickly. Currently it may take 5-15 seconds to destroy a target. Increase the power or add more lasers and they could destroy a target more quickly. There is also microwaves that can be used and EMP to attack electronics and there are computer targeted projectile weapons.