be dangerous you know this is a laser beam here I want to have high collimation this is not very high power so the first thing we have to guarantee is safety what we do is to broaden the laser beam make sure the light intensity is within the safety limit so there's this institute called ANSI that regulates the safety of laser use if you stay within the safely safety element you're very very safe light will be scattered around so if you want to image deep you have to tolerate light scattering we actually allow photons to