Sun Yuxiang, Ren Hongkai, Zhuang Shidong, Wang Xinle
School of Science, Shandong Jianzhu University, Jinan 250101, China.
Institute of Crystal Materials, Shandong University, Jinan 250100, China.
Materials (Basel). 2024 Jan 5;17(2):273. doi: 10.3390/ma17020273.
Theoretical analysis indicated that partially deuterated ammonium dihydrogen phosphate (DADP) crystal with a deuterium content of 23% could realize spectral noncritical phase-matching (S-NCPM) for type-I frequency doubling of an Nd:glass laser. To explore the temperature dependence of the phase matching (PM) angle of the second harmonic generation (SHG) process and the output SHG bandwidth of DADP crystal at 1.053 μm, we used the point-seed rapid-growth method to grow targeted DADP crystal with 23% deuterium content. Experimental results indicated that the grown DADP crystal had high quality and large dimensions (7 × 6 × 6 cm). Using a femtosecond OPO laser as a tunable light source, the temperature dependence of the PM angle of the SHG process in DADP crystal at 1.053 μm was investigated. The PM angle changed linearly with temperature, as predicted by the theoretical calculation. In addition, under the condition of higher temperature, broad bandwidths of the second harmonic of DADP crystal were still observed. These results provide excellent guidance and reference value for the application of wavelength insensitive phase-matched second harmonic generation in partially deuterated DADP.
理论分析表明，氘含量为23%的部分氘代磷酸二氢铵（DADP）晶体可实现Nd:玻璃激光器Ⅰ类倍频的光谱非临界相位匹配（S-NCPM）。为了探究1.053μm下DADP晶体二次谐波产生（SHG）过程的相位匹配（PM）角的温度依赖性以及输出SHG带宽，我们采用点籽晶快速生长法生长了氘含量为23%的目标DADP晶体。实验结果表明，生长出的DADP晶体质量高且尺寸大（7×6×6cm）。使用飞秒光参量振荡器（OPO）激光器作为可调谐光源，研究了1.053μm下DADP晶体中SHG过程的PM角的温度依赖性。如理论计算所预测，PM角随温度呈线性变化。此外，在较高温度条件下，仍观察到DADP晶体二次谐波的宽带宽。这些结果为部分氘代DADP中波长不敏感相位匹配二次谐波产生的应用提供了极好的指导和参考价值。
