I3

The peak of the highest volcano on Earth ("Ojos del Salado" ) is located at an altitude of 6, 893m. It is located in the Andes mountain chain, 2.40km away from the nearest cabin (Refugio Tejos). which is at an altitude of 5800m above sea level. To monitor air quality, it would be necessary to send a laser beam from one point to the other. (a) Calculate the beam size coming from Refugio Tejos to the peak of the volcano using an Ar:Ion laser () = 514.5 nm) if the laser waist is 5mm radius, and is located at the output coupler of the laser beam. Assume the laser output is Gaussian. (b) What would the initial waist radius have to be to have a beam radius of 20cm at the top of the volcano