| Abstract: | We have demonstrated, for the first time to our knowledge, a coupled tandem optical parametric oscillator (OPO) configuration in which a second ZnGeP(2) OPO is placed within the resonator of the first, KTiOPO(4), OPO. A significant enhancement in the overall cascaded efficiency of this OPO compared with standard two-stage OPO's was observed. With a multimode Nd:YAG laser, an overall optical-to-optical efficiency (from 1.06 microm to the mid IR) of 5.2% was obtained from operating only ~1.4 times above oscillation threshold. The measured overall slope efficiency was attractively high at 35%. With a single set of mirrors we obtained a broad wavelength-tuning range from 2.7 to 8 microm. |
