Fig. 1. (a) Three dimensional curve of phase mismatch Δk with respect to incident angle (\begin{document}$ \theta ,\varphi $\end{document}); (b) Phase matching curve under 532 nm laser pumping; (c) Angle tuning curve when \begin{document}$ \varphi $\end{document}=0°

Fig. 2. Schematic diagram of experimental setup (physical image of OPO experimental setup attached on the right)

Fig. 3. Schematic diagram of the relationship between the number of rotations of the knob and the change in crystal rotation angle

Fig. 4. Angle tuning output wavelength of KTO OPO

Fig. 5. Diagram of the relationship between output energy (904 nm)and input energy (532 nm) under different repetition rates