Single-mode operation in a 492.4 nm He-Zn II laser using natural zinc

The single-mode operation on the
4f^{2}F\deg_{7/2}-4d^{2}D_{5/2}
transition at 492.4 nm in a He-Zn II hollow cathode laser with rectangular pulse discharge is accomplished by using natural zinc experimentally. The method using a laser cavity with an internal mode selector is attempted.