Emission dynamics of coupled Nd3+ : YAG lasers with a shared population inversion source

A calculation is made of the frequency spectrum of relaxation oscillations of a cw Nd³⁺ : YAG laser with several lasing channels intersecting in the same active element. It is shown that the highest frequency of relaxation oscillations of isolated channels is virtually retained when these channels are coupled by population inversion, but the other frequencies are reduced. The results of these calculations are in agreement with measurements carried out on a double-beam laser. Experiments are reported on the transition of such a system to dynamic chaos. As in the case of a solid-state laser which emits multimode (in respect of the longitudinal index) radiation, near the frequencies of relaxation oscillations the transition of the investigated system to dynamic chaos follows the Ruelle–Takens–Newhouse scenario.