实验采用激光二极管阵列(LDA)端面抽运Nd∶YVO4晶体，腔内产生1064 nm 和1342 nm 双波长振荡，通过非线性晶体LBO 的I类相位匹配产生连续输出的593.5 nm 和频光。在不同的实验条件下，测量并分析了噪声特性，并用法布里-珀罗干涉仪和光束轮廓仪分别测量了593.5 nm 激光在低噪声与高噪声状态下的纵模结构与横模模式。结果表明：I类相位匹配的和频光噪声情况与其纵模结构密切相关，而抽运功率和谐振腔微调对和频光的纵模结构有很大影响。激光输出在多纵模结构不稳定时的噪声要高于多纵模结构稳定时的噪声。并且激光输出为高阶横模模式时，也会引起激光噪声的增大。

The fundamental wavelengths are oscillated at 1064 nm and 1342 nm in a diode array pumped Nd∶YVO4 laser. Continuous wave (CW) sum frequency generation (SFG) of 593.5 nm is achieved by placing the nonlinear optical crystal LiB3O5 (LBO) cut as type-I phase matched in the cavity. Noise characteristics of CW intracavity SFG laser is measured and analyzed in different experiment conditions. The multi-longitudinal modes structure and transverse modes pattern of SFG laser is observed in high and low noise operation by Fabry-Perot (F-P) scanning interferometer and beam profile instrument, respectively. The results show that noise characteristics of SFG laser is closely related to the multi-longitudinal modes structure which is associated with the pumping power and the resonator cavity perturbation. Compared with unstable multi-longitudinal modes structure, the output laser with stable multi-longitudinal modes structure is lower noise operating. In addition, higher-order transverse modes pattern can also cause the increase of laser noise.