Ding Tingting, Tang Yongzhi, Li Hao, Liu Shijie, Zhang Jing, Zheng Yuanlin, Chen Xianfeng
Opt Lett. 2024 Mar 1;49(5):1121-1124. doi: 10.1364/OL.519484.
Lithium niobate on insulator (LNOI) holds great potential for frequency conversion, where a variety of high-performance nonlinear devices based on different structures has been demonstrated. Here, we report on second harmonic generation (SHG) in MgO-doped LNOI ridge micro-waveguides for efficient green light emission, via an exact type-I noncritical birefringence phase matching (BPM). The LNOI micro-waveguide has a cross section of ∼3×4 m, featuring low coupling loss with lens fiber. The normalized conversion efficiency from a continuous-wave (cw) pump to its second harmonic is measured to be 37%/Wcm in a single-pass configuration. The device shows both relatively high efficiency and a void of periodic poling, offering a potential solution for efficient and scalable green light sources and frequency converters.
绝缘体上铌酸锂（LNOI）在频率转换方面具有巨大潜力，基于不同结构的各种高性能非线性器件已得到证实。在此，我们报道了通过精确的I型非临界双折射相位匹配（BPM），在掺MgO的LNOI脊形微波波导中实现二次谐波产生（SHG）以实现高效绿光发射。该LNOI微波波导的横截面约为3×4μm，与透镜光纤的耦合损耗较低。在单通配置下，从连续波（cw）泵浦到其二次谐波的归一化转换效率经测量为37%/W·cm。该器件既具有相对较高的效率，又无需周期性极化，为高效且可扩展的绿色光源和频率转换器提供了一种潜在解决方案。
