High efficiency deep ultraviolet micro-LED and optical fiber coupling for low power charge management applications

• Published in: Optics and laser technology 2025-02, Vol.181, p.111902, Article 111902
• Main Authors: Ruan, Yuandong, Li, Honggang, Jia, Jiangxie, Gu, Yuning, Zhang, Zhihao, Shen, Daqi, Chen, Xiangyang, Li, Qingqing, Hong, Wei, Cui, Xugao, Zhang, Shanduan, Bai, Yanzheng, Tian, Pengfei
• Format: Article
• Language: English
• Subjects: Charge management; DUV micro-LED; Optical fiber; Test mass
• ISSN: 0030-3992
• DOI: 10.1016/j.optlastec.2024.111902

•A low power charge management system based on deep ultraviolet (DUV) micro-LEDs was proposed.•The size effect of DUV micro-LEDs and optical fibers coupling was studied, determining the optimal coupling size.•Charge management experiments were conducted using DUV micro-LEDs of the optimal size, successfully altering the potential of the test mass. During space gravitational wave detection missions, it is necessary to manage the charge accumulated on the surface of the test mass. A common method involves using optical fibers to transmit ultraviolet (UV) light, leveraging the photoelectric effect for charge management. An important issue in this process is achieving efficient coupling between the UV light source and the optical fiber. In this paper, for the first time we proposed to use DUV micro-LEDs as light sources for charge management systems, which will have lower power consumption. We conducted simulations to investigate the effect of the size ratio between deep ultraviolet (DUV) micro-LEDs and optical fibers on the coupling efficiency. We further employed a direct coupling method to conduct coupling experiments of DUV micro-LEDs and optical fibers with varying wavelengths and sizes. The simulation and experiment results both indicate that, under the influence of both size and divergence angle, there exists an optimal DUV micro-LED size responsible for maximum coupling efficiency between DUV micro-LEDs and optical fibers which is 80 μm when the optical fiber size is 1000 μm. Applying the 80 μm DUV micro-LED in charge management experiments demonstrated the feasibility of using DUV micro-LEDs as light sources for low power charge management systems, achieving rapid charge–discharge rates and high photoelectric current at lower driving electrical power.