近日，南洋理工大学Wang, Qi Jie团队研究了超紧凑型多束态辅助平带激光器。2025年4月28日，《自然—光子学》杂志发表了这一成果。

具有低阈值和稳定单模操作的高度紧凑的激光器对集成光电子的需求很大。然而，小腔中相当大的侧漏和辐射损失大大降低了质量（Q）因子，对追求高性能微型激光器构成了重大障碍。研究组提出并实验证明了一种由连续体中的多个束缚态补充的平带激光器。通过同时限制所有三个维度的光，报道了横向尺寸为~3λ的超紧凑太赫兹量子级联激光腔中约1440的高Q因子。 

尽管器件占地面积小，但场限制使得实现具有低阈值电流密度的电泵浦单模太赫兹激光器成为可能。这种表面发射激光器发出具有良好方向性的明确光束。所展示的多束态辅助平带设计也适用于其他波长范围，为适合广泛应用的节能、单片集成和超紧凑激光源提供了一条途径。

附：英文原文

Title: Ultracompact multibound-state-assisted flat-band lasers

Author: Cui, Jieyuan, Han, Song, Zhu, Bofeng, Wang, Chongwu, Chua, Yunda, Wang, Qian, Li, Lianhe, Davies, Alexander Giles, Linfield, Edmund Harold, Wang, Qi Jie

Issue&Volume: 2025-04-28

Abstract: Highly compact lasers with a low threshold and stable single-mode operation are in great demand for integrated optoelectronics. However, considerable side leakages and radiation losses in small cavities substantially degrade the quality (Q) factor, posing a substantial obstacle in pursuing high-performance miniature lasers. Here we propose and experimentally demonstrate a flat-band laser supplemented by multiple bound states in the continuum. By simultaneously confining light in all three dimensions, a high Q factor of ~1,440 in an ultracompact terahertz quantum cascade laser cavity with a lateral size of ~3λ is reported. The field confinement makes it possible to realize an electrically pumped single-mode terahertz laser with a low threshold current density, despite the small device footprint. This surface-emitting laser emits a well-defined beam with good directionality. The demonstrated multibound-state-assisted flat-band design is also applicable to other wavelength regimes, offering a route to energy-efficient, monolithically integrated and ultracompact laser sources that suit a wide range of applications.

DOI: 10.1038/s41566-025-01665-6

Source: https://www.nature.com/articles/s41566-025-01665-6