Tough Way
That may work - however, significant efficiency loss at ruby /air boundary for the exit beam and the re-entrant beam. The external mirrors would need 1st surface coatings (silvering) and perfect parallel alignment.
The ruby rods have been ground & polished to perfect parallelism and thus are very efficient. The lasing action occurrs when light bounces from mirror to mirror within the rod - building in intensity as it courses to and fro in the medium.
That may work - however, significant efficiency loss at ruby /air boundary for the exit beam and the re-entrant beam. The external mirrors would need 1st surface coatings (silvering) and perfect parallel alignment.
The ruby rods have been ground & polished to perfect parallelism and thus are very efficient. The lasing action occurrs when light bounces from mirror to mirror within the rod - building in intensity as it courses to and fro in the medium.