[Captain_Usher]

I'm sure there's something like what you're describing in existence, probably in a lab somewhere, clamped in front of a metal plate with burn marks on it. I think you're out of luck on commercially available man-portable lasers for effectively shooting down a drone in a real-world scenario. There's a reason why people making videos of their lasers on Youtube are using them to pop balloons.

Even if that sort of laser for sale at a reasonable cost, you probably don't want or need one for killing drones. If you've escalated to actually blowing the drone out of the sky, you might as well use a gun. Guns are great at that and they're much cheaper. The bullets and shot you fire into the air do pose a safety risk on the way back down, but if reasonable steps are taken it's probably not a big enough deal to justify using a laser instead. (Caveat: in dense urban areas it's very difficult to even begin taking those "reasonable steps" and firing anything into the air is a recipe for tragedy. If you're seriously looking to take out a drone in a city, a laser makes a lot more sense.)

Another downside is that the laser needs to be held on its target to work, and that's a pain in the ass when the target is a drone. Even a relatively stable model flown by a skilled operator is still going to bob and weave, and the drone is presumably not hovering perfectly still while you're trying to break it. Today, hitting that target once with a shotgun is probably easier than holding a laser on it for the amount of time you'd need.

In the future, that will probably not remain true. Lasers (or really any devices that emit energy in a tight beam) are inherently better long-range direct-fire weapons than firearms because the laser moves in a straight line and you can get it to go farther. Travel time is pretty obviously another area where lasers win. As laser technology improves, we'll see more powerful lasers that can do damage in less time and automated platforms for doing the aiming. A future scenario where militaries use automated energy weapons against unmanned aircraft is very realistic, so a future scenario where a police officer shoots down a drone with a laser is certainly within the realm of possibility.