New concept of multipass resonators for gas and solid-state lasers

Recently we, have offered a relatively new concept of creation of steady multipass resonators for lasers with large volume of active media. This concept was proved in details in our research and developments of CO₂ lasers with transversal RF pumping. In the present work the results of numerical modeling of such resonators are given. It has been investigated the stability of such resonators is designed at various geometry, their sensitivity to misalignments, the losses for various types of modes, opportunity of various laser transitions or mode selection and so on. The high sensitivity of the laser output characteristics to parameters of lateral reflectors is shown. In the present work it is offered the qualitatively new approach to create the active elements and resonators for compact solid-state lasers with diode pumping on the basis of the same idea.. A lot of new schemes of lasers is discussed, as well as the results of experimental investigations of a microchip Tm:YAlO₃ diode pumped laser with the cw output power up to 0.5 W and a slope efficiency up to 40%.