Design an argon ion laser cavity such that the following criteria are met. the argon ion laser is a gas i. discharge device that lases at 488 nm. a) the far field divergence is 1 mrad( half angle). b) the longitudinal mode spacing (free spectral range) is 500 mhz provide: i. a sketch of the system il. supporting calculations that the system performs to specifications iii. supporting calculations that the system is stable iv. find: what are the spot sizes on the cavity mirrors?