The 488.1-nm radiation of a single-mode Ar+ ion laser was used to excite Na2 molecules in a heat-pipe oven. The experimental arrangement is shown in Fig. 1. In a short linear resonator the emitted 532-nm dimer laser light shows strong fluctuations of power. An interferometric experiment revealed that density fluctuations due to temperature gradients in the oven are far too small to explain this observation. As the mechanical stability of the resonator proved to be of great influence, we investigated the possibility that the unstable emission could result from a misfit between the narrow gain profile exhibited by the Na2 laser and the fluctuating position of axial modes in a short mechanically unstabilized linear resonator.
© 1982 Optical Society of AmericaPDF Article