Lasers can be used safely and productively in airspace. This is a brief listing of lasers being used outdoors in a (generally) non-hazardous way. If you are interested in learning about any of these, perform a Google search; we do not have any additional details at this time.

Laser light shows
Outdoor concerts and special events

Astronomy
Laser guidestars for adaptive optics telescopes

Communications
Lasers for point-to-point free space communication

LIDAR (LIght Detection And Ranging)
For atmospheric monitoring
For ranging and imaging
For aerial mapping
Satellite laser ranging
Ceilometers

Aviation
Security: Visual warning to aircraft entering a restricted zone (in active use, at least in the DC area)
Foreign Object Debris (FOD) detection
Laser guideslope system (may be a prototype that is not in active use)
Laser centerline system (may be a prototype that is not in active use)

Military
Laser dazzlers — to interfere with persons presenting threats
Laser illuminators
Range designators and rangefinders
Counter MANPADS (Man-Portable Air Defense Systems)

Other
Lasers used for bird dispersion
Pipeline patrol searching for gas leaks
Lasers used for paint stripping