Effect of hydrogen additive on the evolution of beam divergence in copper bromide lasers

We present a systematic study of the effect of hydrogen additive on the beam quality of copper bromide lasers. It is a well-established fact that the addition of small amounts of hydrogen to the neon buffer gas of this class of laser will dramatically increase their average output power and efficiency. Our results show that the partial pressure of hydrogen used to maximize the total output power is not the same as that which optimizes the power density in the drilling plane of a copper bromide laser based micro-machining system.