Ultra-high spectral purity laser derived from weak external distributed perturbation
약외부 천이 교란하여 발생하는 초고스펙트럼 순도 레이저
Láseres de pureza hiperespectral producidos por perturbaciones de tela parcial externa débiles
Laser ultra - haute pureté spectrale généré par une faible perturbation partielle externe du tissu
лазер сверхвысокой спектральной чистоты
Laiyang Dang 党来杨, Ligang Huang 黄礼刚, Leilei Shi 史磊磊, Fuhui Li 李阜徽, Guolu Yin 尹国路, Lei Gao 高磊, Tianyi Lan 兰天意, Yujia Li 李雨佳, Lidan Jiang 蒋丽丹, Tao Zhu 朱涛
Key Laboratory of Optoelectronic Technology and Systems (Education Ministry of China), Chongqing University, Chongqing 400044, China
中国 重庆 重庆大学光电技术及系统教育部重点实验室
Ultra-high spectral purity lasers are of considerable research interests in numerous fields such as coherent optical communication, microwave photonics, distributed optical fiber sensing, gravitational wave detection, optical clock, and so on. Herein, to deeply purify laser spectrum with compact size under normal condition, we propose a novel and practical idea to effectively suppress the spontaneous radiation of the laser cavity through weak external distributed perturbation.
Subsequently, a laser configuration consisting of a main lasing cavity and an external distributed feedback cavity is proposed. The feedback signal with continuous spatio-temporal phase transition controlled by a distributed feedback structure is injected into the main cavity, which can deeply suppress the coupling rate from the spontaneous radiation to the stimulated emission and extremely purify the laser spectrum. Eventually, an ultra-narrow linewidth on-chip laser system with a side mode suppression ratio greater than 80 dB, an output linewidth of 10 Hz, and a relative intensity noise less than -150 dB/Hz is successfully obtained under normal conditions.
The proposed concept in this work provides a new perspective for extreme regulation of laser parameters by using weak external distributed perturbation, which can be valid for various gain-type lasers with wide wavelength bands.