What about putting an Arduino ultrasound module??

#1
What about putting an Arduino ultrasound module for misuring the depth of what the laser is pointing at and then a variable focal point lens so that the laser is more in focus?
 
#2
What about putting an Arduino ultrasound module for misuring the depth of what the laser is pointing at and then a variable focal point lens so that the laser is more in focus?
I'm not familiar with this. What would be the advantages & disadvantages? Have you tried to use this? What did you think of it?