Tunable Ultra‐Narrow Linewidth Light Source Through Liquid Crystal‐Assisted Mini‐Bound‐States‐In‐Continuum Cavities

• Published in: Advanced optical materials 2024-11, Vol.12 (32), p.n/a
• Main Authors: Tang, Renjie, Wang, Yiting, Jian, Jialing, Ju, Zezhao, Si, Yalan, Wu, Jianghong, Ye, Yuting, Shi, Yilin, Bao, Kangjian, Wu, Yingchun, Tang, Yiheng, Sun, Chunlei, Gao, Dawei, Lin, Hongtao, Li, Lan
• Format: Article
• Language: English
• Subjects: Biocompatibility; Indium phosphides; InP quantum dot; Inventions; Light emission; Light sources; liquid crystal; Liquid crystals; Microcavities; Photonic crystals; Quantum dots; Sensitivity; Sensor arrays; ultra‐narrow linewidth; wavelength‐tunable
• ISSN: 2195-1071; 2195-1071
• DOI: 10.1002/adom.202401592

The introduction of liquid crystals into microcavities has garnered considerable attention for their exceptional tunability and high sensitivity to external perturbation factors within their distinct phase states. Here, a novel light source with both wavelength tunability and an exceptionally narrow linewidth is presented. This innovation is realized by strategically manipulating LC molecules, transitioning them from a well‐aligned state to a disordered state with increasing temperature. The microcavity is tailored to support bound states in the continuum, a cutting‐edge concept in photonic research that allows for light localization with minimal loss. In the pursuit of potential biocompatibility and to reduce cytotoxicity, indium phosphide colloid quantum dots are opted to serve as the emissive carriers within the system. An ultra‐narrow linewidth light emission of 0.039 nm is observed, corresponding to a quality factor reaching 16668, along with a tunable range of 1.21 nm and a temperature sensitivity of 33.52 pm K−1. The invention's compact size and tunable character make it an ideal candidate for a variety of potential applications, such as eco‐friendly sensors with minimal ecological impact, optical modulators with precise control over light, and adaptable photonic devices that can be integrated with a diverse array of materials and configurations. A tunable ultra‐narrow linewidth light emission from a liquid‐crystal‐based photonic crystal cavity is experimentally demonstrated. The article thoroughly studies the design of cavities, ultra‐narrow linewidth light sources based on InP quantum dot, and liquid crystal‐assisted wavelength tuning. The devices exhibit a quality factor of 16 668, a sensitivity of 33.52 pm K−1, and a total tuning range of 25.7 nm.