Observations on a concentric spherical cavity laser oscillator

Experimental results on a number of ruby rods in concentric spherical cavities are presented and discussed. The observations include intensity variations (spiking) as a function of input energy, longitudinal and transverse mode structure, and output energy distribution. The characteristics of flat and concentric cavities are compared using the data presented. The spiking frequencies and decay times are compared with simple rate equation predictions during the quasi-CW time of operation with reasonable agreement. Results indicate that the cavity effects will be similar regardless of the type of laser material used.