Actually the system is a linear, end pumped laser system with a <4W pump diode. YVO4/1064nm generation is surprisingly efficient as the absorption spectrum of YVO is greater than YAG plus the cavity design adds to the efficiency if the pump diode is properly collimated and focused. You don't just shoot a beam of 808nm into the crystal. It's a maximization issue relating to beam waist within the YVO active area (due to a hemispherical OC) versus absorption by nonactive regions that sets the pump diode cross section entering the YVO and the depth of focus.