Couldn't you start of with a larger (meter wide) lens and focusing mechanism, so that it narrows down at the target? Then you aren't heating up most of the air

Couldn't you start of with a larger (meter wide) lens and focusing mechanism, so that it narrows down at the target? Then you aren't heating up most of the air between. Also what about high output short pulsed lasers? Couldn't you get much higher output for a brief enough duration that it wouldn't heat up the air?