Redeckas Karolis, Jakštas Vytautas, Bernatonis Matas, Tamošiūnas Vincas, Valušis Gintaras, Minkevičius Linas
Department of Optoelectronics, Center for Physical Sciences and Technology (FTMC), Saulėtekio Ave. 3, LT-10257 Vilnius, Lithuania.
Institute of Photonics and Nanotechnology, Vilnius University, Saulėtekio Ave. 3, LT-10257 Vilnius, Lithuania.
Sensors (Basel). 2025 Jan 3;25(1):229. doi: 10.3390/s25010229.
The practical implementation of terahertz (THz) imaging and spectroscopic systems in real operational conditions requires them to be of a compact size, to have enhanced functionality, and to be user-friendly. This work demonstrates the single-sided integration of Fresnel-zone-plate-based optical elements with InGaAs bow-tie diodes directly on a semiconductor chip. Numerical simulations were conducted to optimize the Fresnel zone plate's focal length and the InP substrate's thickness to achieve constructive interference at 600 GHz, room-temperature operation and achieve a sensitivity more than an order of magnitude higher-up to 24.5 V/W-than that of a standalone bow-tie detector. Investigations revealed the strong angular dependence of the incident radiation on the Fresnel zone plate-integrated bow-tie diode's response. These findings pave a promising avenue for the further development of single-sided integration of flat optics with THz detectors, enabling improved sensitivity, simplified manufacturing processes, and reduced costs for THz detection systems in a more compact design scheme.
太赫兹（THz）成像和光谱系统在实际运行条件下的实际应用要求它们体积紧凑、功能增强且用户友好。这项工作展示了基于菲涅耳带板的光学元件与铟镓砷蝴蝶结二极管直接在半导体芯片上的单面集成。进行了数值模拟以优化菲涅耳带板的焦距和磷化铟衬底的厚度，以在600吉赫兹实现相长干涉、室温运行，并实现比独立蝴蝶结探测器高一个数量级以上（高达24.5伏/瓦）的灵敏度。研究揭示了入射辐射对菲涅耳带板集成蝴蝶结二极管响应的强烈角度依赖性。这些发现为太赫兹探测器与平面光学器件的单面集成的进一步发展铺平了一条充满希望的道路，从而能够在更紧凑的设计方案中提高太赫兹检测系统的灵敏度、简化制造工艺并降低成本。
