论文标题
薄膜锂niobite波导设备的高效和极化独立边缘耦合器
High-efficient and polarization independent edge coupler for thin-film lithium niobite waveguide devices
论文作者
论文摘要
由于其具有吸引力的光学特性，Niobate（LN）设备已被广泛用于光学通信和非线性光学元件。薄膜在绝缘子（LNOI）上的出现大大改善了基于LN的设备的性能。但是，对于实用应用，基于LNOI的设备仍然需要高效的纤维芯片光学耦合器。在本文中，我们证明了基于LNOI的高效和极化独立的边缘耦合器。通过标准半导体工艺制造的耦合器显示，当TE/TM光的纤维芯片耦合损失分别为0.54 db/0.59 db，每个刻面的TE/TM光均为1550 nm，与超高数值孔径纤维（UHNAF）耦合到哪种模式模式直径约为3.2微米。对于超过1527nm的波长，TE和TM灯的耦合损耗低于1dB/facet。还证明了相对较大的光学未对准能力。耦合器显示出高光功率和温度变化的有希望的稳定性。
Lithium niobate (LN) devices have been widely used in optical communication and nonlinear optics due to its attractive optical properties. The emergence of thin-film lithium niobate on insulator (LNOI) improves performances of LN-based devices greatly. However, a high-efficient fiber-chip optical coupler is still necessary for the LNOI-based devices for practical applications. In this paper, we demonstrate a highly efficient and polarization-independent edge coupler based on LNOI. The coupler, fabricated by standard semiconductor process, shows a low fiber-chip coupling loss of 0.54 dB/0.59 dB per facet at 1550 nm for TE/TM light respectively, when coupled with ultra-high numerical aperture fiber (UHNAF) of which mode field diameter is about 3.2 micrometers. The coupling loss is lower than 1dB/facet for both TE and TM light at wavelengths longer than 1527nm. A relatively large tolerance for optical misalignment is also proved. The coupler shows a promising stability in high optical power and temperature variation.
