中文摘要：

稀土金属镱原子的3P2态是镱原子的一个很重要的长寿命亚稳态,为了研究将跃迁1S0→3 P2作为镱原子钟跃迁的可能性,通过507nm的激光场进行激发而实现态制备.实验中利用波导型周期极化铌酸锂作为倍频晶体的单次倍频方式,采用了一种简单的短焦距单透镜耦合方式,获得了507nm的连续光输出.结果表明,采用焦距为20mm的单透镜将58mW的1 014nm基频光直接耦合到波导结构的周期极化铌酸锂,得到了86.5μW的507nm倍频光.同时,给出了倍频输出光的输出功率与温度的关系曲线.对比传统的裸光纤直接耦合方式,单透镜直接耦合方式优于光纤耦合的倍频效率.

英文摘要：

3P2 state of rare-earth-metal ytterbium atoms is a very important meta-stable state with long lifetime. In order to study probability of 11S0→3 P2transition as a clock transition for ytterbium atoms, state preparation has to be realized with help of 507 nm light field. In order to obtain second harmonic generation（SHG） of 507 nm with a waveguide periodically poled lithium niobate nonlinear crystal （WG PPLN）, a simple coupling method with single short-focus lens was adopted. Experimental results show that we can get output power of 86.5/~W at 507nm with single lens（f=20 mm） coupling scheme, the input power of fundamental laser at t 014 nm is around 58.2 mW. With the method of lens coupling, the relation between the output power and phase matching temperature was given. By contrast, we conducted the coupling of the WG PPLN with bare fiber, as the usual way used by other groups. It shows that the higher doubling efficiency with single lens is obtained compared with that with a fiber case.