Hey guys! I am currently working on some tasks to improve and expand my skills, but I can not go on with the following task An Nd-YAG laser (D=5mm diameter) is focussed with a lens (f = 200mm). I: How big is the laser beam at its waist? (Solved) II: What is the largest bundle behind the lens occurring in the optical axis (beam axis)? (Solved) III: How long is the zone around the waist in which the beam is smaller than 0.2mm? (Solved) IV: What is the average power density? (P= 3 Watt) V: What is the peak power when the laser delivers the 3 watts in the form of 10000 pulses per second, each of which is 20 ns long? Already identified solutions To I: (1060nm wavelength) With d= 2,44 α x f / D I get as size for the laser beam at a waist of 1.035x10-4m ((2,44x1.06x10-6m x 2 x 10-1m)/5x10-3m) To II: tan α = 0,5D - 0,5 d /f = 2,5 x 10-3m - 0,5 x 1.035 x 10 -4m / 2 x 10 -1m = 0,01225 tan -1(0,01225)=0,702 α = 0,7° To III: tan α = 0,2mm / a a = 0,2mm / tan α =16,3mm To IV: I = P / A = P = 3 W I= 3W / 0,5 x 1.035 x 10-4m2Pi Am I right with these considerations / approaches? Can you help me with the last two tasks?