An all solid-state continuous-wave yellow laser at 570 nm is firstly reported. The yellow laser is from two Nd∶YAG spectral lines of 1 444 nm and 946 nm with a nonlinear sum frequency

and the two spectral lines correspond to their energy levels of crystal transition for 4F3/2-4I15/2 and 4F3/2-4I9/2

respectively. By using a doubly folded-cavity

the yellow laser at 570 nm is obtained by a intra-cavity sum frequency mixing of type-II critical phase matching KTP crystal at 1 444 nm and 946 nm.The outpower of yellow laser vs incident pump powers is measured

results indicate that when pump powers injected into two Nd∶YAG crystals are 24 W and 15 W

respectively

the 570 nm yellow laser of 560 mW can be obtained

and its power stability in 4 h is better than ±2.8%. Furthermore

the beam quality of the yellow laser is measured by a beam quality analyzer in an output power of 560 mW

and results show its beam quality factor M2 is 2.3 in the laser with a maximum sum-frequency output.