There's nothing particularly special about a lased photon compared to any other photon, so the only way to block them is a coating that absorb/reflects the appropriate wavelength.
You can't block them all, because then it's no longer a window!
You can add a dichroic (or similar) coating to reflect certain specific wavelengths, such coatings are actually relatively cheap (commercially available ones) - and this is already done anyway in commercial airliners as part of the very complex armoured glass windows of the cockpit.
I don't know the specifics of what they block, but I'd guess IR is blocked as a matter of course as that can easily damage sight, leaving only visible lasers.
Secondly "sweep the laser spectrum"? It's not broadcast!
Lasers emit a coherent beam of light. Thus anywhere that you can see the aircraft is a 'possible vantage point'. This extends for many miles beyond the airfield, and considerably further than you could see from any possible place in the airfield.
At night, if it's misty/hazy or dusty then you might be able to see the beam as it reflects off particles in the air and backtrack that to where the line intersects the ground.
However, this requires two viewers at different locations who can act immediately, before the perpetrator runs away. These things are very small - smartphone or smaller.
Basically, this is not something the airport can enforce, it's something that the police need to - because they are the only group in a position to both see the beam and act upon it.
Unfortunately, the lasers powerful enough to dazzle a plane have another excellent feature - they can all temporarily (and in some cases permanently) blind you with very brief exposure.
Although with any luck the oiks doing this will blind themselves.