ZnO film is promising for high frequency surface acoustic wave device application when coupled with diamond. In order to get good performance and reduce insertion loss of the device, which demand a piezoelectric material possessing high electrical resistivity and piezoelectric constant d33, Cu-doped ZnO films have been prepared by direct current reactive magnetron sputtering using a zinc target with various Cu-chips attached. The influences of a Cu-doping condition on the microstructure and properties of ZnO films are investigated by x-ray diffraction, x-ray photoelectron spectroscopy, a four-point probe resistivity test system and the periodic compressional force method. The experimental results indicate that high resistivity (9 × 108 Ω cm) and piezoelectric constant (d33 = 13.5 pC N−1) ZnO films with perfect c-axis orientation and fine grain polycrystalline can be achieved by 2.0 at% Cu-doping. The contribution of the Cu-doping to the electrical resistivity and piezoelectric constant d33 is discussed.

A high-power and narrow-linewidth tunable optical parametric oscillator based on PPMgLN is presented. The phase matching type e → e + e is used to avoid the walk-off effect and utilize the maximum nonlinear coefficient d 33 (27.4 pm V −1 ) of the PPMgLN crystal (5 mol% MgO doped). When the pump power of the 1064 nm laser is 50 W and the temperature of the PPMgLN crystal is 100 • C, average output power of 15.8 W is obtained with a slope efficiency of 40.6%. The 1.655 µm signal and 2.98 µm idler output powers are 9.5 W and 6.3 W, respectively. The linewidth of the 1.655 µm signal laser is 1.00 nm before compression and 0.05 nm after compression. The compression ratio is 20. The linewidth of the 2.98 µm idler laser is within 0.30-0.63 nm based on theoretical analysis of the linewidth of the 1064 nm pump laser and 1.655 µm signal laser. The output wavelength can be tuned from 1.6 to 1.8 µm and from 3.1 to 2.7 µm by changing the temperature of the 31.2 µm PPMgLN crystal from 30 to 200 • C.