韩国先进科学技术院（KAIST）SangHyeon Kim团队研究了基于辐射热效应的室温波导集成光电探测器在中红外光谱中的应用。相关论文发表在2025年3月19日出版的《光：科学与应用》杂志上。

波导集成中红外（MIR）光电探测器是利用成熟的光子集成电路（PIC）技术开发分子光谱应用的关键组件。尽管有各种策略，但在实现宽带光响应、无冷却操作和大规模互补金属氧化物半导体（CMOS）兼容可制造性方面仍然存在关键挑战。为了超越这些限制，人们将辐射热测量效应（一种热检测机制）引入波导平台。

更重要的是，研究组在锗（Ge）中追求自由载流子吸收（FCA）工艺，以创建高效的光吸收介质，为完全覆盖MIR光谱提供了一种实用的解决方案，而无需在CMOS中引入外来材料。他们提出了一种基于绝缘体上锗（Ge-OI）PIC架构的非制冷波导集成光电探测器，该架构利用了辐射热效应和FCA。值得注意的是，该设备在4030-4360nm（甚至可能更高）范围内表现出28.35%/mW的宽带响应率，挑战了现有技术，同时在4180nm处实现了4.03×10^-7W/Hz^0.5的噪声等效功率。

研究组进一步演示了使用集成在单个芯片上的光电探测器和传感波导对气态二氧化碳（CO₂）进行无标签传感。这种室温波导集成MIR光电探测方法，利用Ge中FCA的测辐射热法，不仅有助于实现具有波长灵活性的完全集成的片上实验室系统，而且为具有CMOS代工兼容性的MIR PIC提供了蓝图。

附：英文原文

Title: Room-temperature waveguide-integrated photodetector using bolometric effect for mid-infrared spectroscopy applications

Author: Shim, Joonsup, Lim, Jinha, Kim, Inki, Jeong, Jaeyong, Kim, Bong Ho, Kim, Seong Kwang, Geum, Dae-Myeong, Kim, SangHyeon

Issue&Volume: 2025-03-19

Abstract: Waveguide-integrated mid-infrared (MIR) photodetectors are pivotal components for the development of molecular spectroscopy applications, leveraging mature photonic integrated circuit (PIC) technologies. Despite various strategies, critical challenges still remain in achieving broadband photoresponse, cooling-free operation, and large-scale complementary-metal-oxide-semiconductor (CMOS)-compatible manufacturability. To leap beyond these limitations, the bolometric effect – a thermal detection mechanism – is introduced into the waveguide platform. More importantly, we pursue a free-carrier absorption (FCA) process in germanium (Ge) to create an efficient light-absorbing medium, providing a pragmatic solution for full coverage of the MIR spectrum without incorporating exotic materials into CMOS. Here, we present an uncooled waveguide-integrated photodetector based on a Ge-on-insulator (Ge-OI) PIC architecture, which exploits the bolometric effect combined with FCA. Notably, our device exhibits a broadband responsivity of 28.35%/mW across 4030–4360nm (and potentially beyond), challenging the state of the art, while achieving a noise-equivalent power of 4.03×107W/Hz0.5 at 4180nm. We further demonstrate label-free sensing of gaseous carbon dioxide (CO2) using our integrated photodetector and sensing waveguide on a single chip. This approach to room-temperature waveguide-integrated MIR photodetection, harnessing bolometry with FCA in Ge, not only facilitates the realization of fully integrated lab-on-a-chip systems with wavelength flexibility but also provides a blueprint for MIR PICs with CMOS-foundry-compatibility.

DOI: 10.1038/s41377-025-01803-3

Source: https://www.nature.com/articles/s41377-025-01803-3