Fig. 1. Schematic of optical path of 914 nm vortex Nd∶YVO₄ laser based on spherical aberration cavity

Fig. 2. Resonator stability as a function of focal length of lens L1 and d₂

Fig. 3. Effective focal length of K9 plano-convex lens versus incident height (beam radius)

Fig. 4. Typical beam patterns recorded in experiment

Fig. 5. Selective range of angular indices m for LG_{0,±mmode that can achieve single-mode operation under different pump powers}

Fig. 6. LG mode order and output power versus displacement of output mirror M2