Hi, I'm a complete and utter newb at laser pointers - but, scientifically inclined and an engineer by training. I'm hoping for a recommendation for an inexpensive consumer laser pointer with the lowest divergence that's reasonably possible.
The application is for a science project for my teens. Basically, it involves sending a laser beam over a long distance (1-2 miles), having it bounce back via a corner-cube retroreflector, and detecting the arriving laser light (hopefully via the naked eye / protected eye). My quick and possibly flawed back of the envelope calculations show that laser pointers with divergence rates in the 1mRad range will have a beam spread up to about 1-2 meters across upon arrival. Anything I can do to reduce that would be ideal.
I'm also hoping not to break the bank. Used gear is fine - as is using a lens to focus the beam.
thoughts?
The application is for a science project for my teens. Basically, it involves sending a laser beam over a long distance (1-2 miles), having it bounce back via a corner-cube retroreflector, and detecting the arriving laser light (hopefully via the naked eye / protected eye). My quick and possibly flawed back of the envelope calculations show that laser pointers with divergence rates in the 1mRad range will have a beam spread up to about 1-2 meters across upon arrival. Anything I can do to reduce that would be ideal.
I'm also hoping not to break the bank. Used gear is fine - as is using a lens to focus the beam.
thoughts?