Rapid, precise, and real-time monitoring of water content in ethanol solution is essential in a variety of demanding practical and industrial applications. Here, we demonstrate the fabrication of a compact GaN-based photonic chip for monitoring the water concentration in ethanol. Light from the emitter can be coupled to the monolithic integrated detector through the sapphire substrate. The detected photocurrent signal varies with the optical reflectance at the sapphire/ethanol interface. Through a series of experiments, the feasibility of the photonic chip is verified by revealing its compact structure, subsecond response, high sensitivity to extremely low water content, and high stability.

中文翻译：

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紧凑的基于GaN的光子芯片，用于乙醇中低水分含量的原位实时监测

在各种要求苛刻的实际和工业应用中，快速，精确和实时监控乙醇溶液中的水分至关重要。在这里，我们演示了用于监测乙醇中水浓度的紧凑型GaN基光子芯片的制造。来自发射器的光可以通过蓝宝石衬底耦合到单片集成检测器。检测到的光电流信号随蓝宝石/乙醇界面的光反射率而变化。通过一系列实验，通过揭示其结构紧凑，亚秒级响应，对极低水含量的高灵敏度以及高稳定性，证明了光子芯片的可行性。