My easiest (and still in use) air nozzle consists of a basketball inflator needle, small length of copper wire, flexible hose, and air compressor.
Fabrication:
1. Cut back the pointed end of the needle to expose the insides.
2. Wrap a few turns of 16 gauge copper wire around nozzle and attach the other end of the wire to the laser heat sink assembly.
3. Connect the input side of the needle to a small air compressor with flexible tubing.
Notes:
1. Have tried four different compressors ranging from aquarium to air tool and currently use a compressor
intended for air brush. You do not need high pressure
2. The copper wire allows for easy adjustment of nozzle position.
3. Some other forum member(s) have used an output from the controller to control an ON/OFF solid state relay.