Erbium-doped lithium niobate on insulator (Er:LNOI) is a promising platform for photonic integrated circuits as it adds gain to the LNOI system and enables on-chip lasers and amplifiers. A challenge for the Er:LNOI laser is to increase its output power while maintaining single-frequency and single (-transverse)-mode operation. In this work, we demonstrate that single-frequency and single-mode operation can be achieved even in a single multi-mode Er:LNOI microring by introducing mode-dependent loss and gain competition. In a single microring with a free spectral range of 192 GHz, we have achieved single-mode lasing with an output power of 2.1 µW, a side-mode suppression of 35.5 dB, and a linewidth of 0.9 MHz.

中文翻译：

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绝缘体上掺铒铌酸锂的单频单谐振腔激光器

绝缘体上掺铒铌酸锂 (Er:LNOI) 是一种很有前途的光子集成电路平台，因为它增加了 LNOI 系统的增益并实现了片上激光器和放大器。Er:LNOI 激光器面临的挑战是在保持单频和单（横向）模式操作的同时增加其输出功率。在这项工作中，我们证明了通过引入与模式相关的损耗和增益竞争，即使在单个多模 Er:LNOI 微环中也可以实现单频和单模操作。在自由光谱范围为 192 GHz 的单个微环中，我们实现了输出功率为 2.1 µW、边模抑制为 35.5 dB 和线宽为 0.9 MHz的单模激光。