Abstract

The variable configuration multirod resonator (VCR) is capable of producing fundamental mode output with high power at a high efficiency from a small resonator.¹ It consists of three Nd:YAG rods in a folded cavity so that each rod is endpumped by a fibre coupled diode laser. This gives it good mode overlap in the pump beam and ability to overcome the problem of thermal lensing so that it can produce up to 13W cw. In order to obtain very high peak powers from the VCR, it is necessary that it be Q-switched. The VCR has stability properties that point towards a new form of Q-switching which does not require significant changes to the efficient cw set-up. It is possible, by choosing suitable dimensions and pump powers, to have the resonator stable when operating as a ring resonator but to be unstable when operating as a Fabry-Perot Resonator. In the VCR the difference between the resonator being in Fabry-Perot and ring configurations is simply the presence or otherwise of a quarter wave element.

© 1998 IEEE