Investigation of the lasing mechanism HCN molecular laser

This thesis describes the construction and operation of various HCN laser systems with a view to determine the mechanism of operation. In one system to simplify the processes occuring within the discharge tube, nitrogen was excited by a microwave discharge before entering the cavity. This coupled with the thermal decomposition of a peroxide reduced the d.c. threshold current for laser operation down to 5mA. CW laser oscillation in pure HCN was studied together with the influence of foreign gases on the laser. It is concluded that a simple one or two stage process does not produce the population inversion but that a multiple stage process, which could be difficult to identify, is always involved.