I型准相位匹配周期性极化铌酸锂倍频蓝光输出

Blue Light Generation by Type I Quasi-Phase-Matching Frequency Doubling in Periodically Poled LiNbO_3

在周期为 14 .5 μm的周期性极化铌酸锂中 ,利用d3 1,得到了一阶I型EωYEωY-E2ωZ (oo-e)准相位匹配蓝光二次谐波。在 15 0℃下 ,由 114 μJ抽运光 ,得到了 5 2 μJ ,0 .4 73μm倍频蓝光 ,对应于平均最大转换效率 4 5 .6 %。制备了一阶和三阶周期分别为 4 .5 μm和 13.5 μm的周期性极化铌酸锂。在EωZEωZ-E2ωZ (ee -e)准相位匹配 0 .4 73μm蓝光倍频中 ,15 0℃下 ,分别得到了 4 1.3%和 19%的倍频转换效率。oo -e准相位匹配比传统的ee -e准相位匹配有较大的光栅周期 ,尤其在短波长区域倍频输出应用中 ,降低了周期性结构制作的困难 ,其较大的容许带宽在实验中提高了频率转换效率。实验结果表明了在周期性极化铌酸锂中准相位匹配倍频的偏振相关性。

First-order type I E ω YE ω Y-E 2ω Z (oo-e) quasi-phase-matched (QPM) blue harmonic generation was demonstrated in periodically poled LiNbO 3 (PPLN) with period of 14.5 μm by using d 31 . In a single-pass configuration, corresponding to the highest frequency conversion efficiency of 45.6%, 52 μJ of harmonic blue light at 0.473 μm was generated from an input of 114 μJ at 150 ℃. It was also demonstrated the conveentional QPM E ω ZE ω Z-E 2ω Z (ee-e) blue second harmonic generation (SHG) of 0.473 μm in PPLN with the first order period of 4.5 μm and the third order period of 13.5 μm at 150 ℃, whose conversion efficiency were 41.3% and 19% respectively. The larger grating period for the type I QPM (oo-e) than for the conventional QPM (ee-e), lowers the fabrication constrains especially in the short-wavelength region, which increases the acceptance bandwidth and enhances the frequency conversion efficiency in experiment. The experimental results show the polarization dependence of QPM SHG in PPLN.