In this work, a novel ultrafast optoelectronic proximity sensor based on a submillimeter-sized GaN monolithic chip is presented. Fabricated through wafer-scale microfabrication processes, the on-chip units adopting identical InGaN/GaN diode structures can function as emitters and receivers. The optoelectronic properties of the on-chip units are thoroughly investigated, and the ability of the receivers to respond to changes in light intensity from the emitter is verified, revealing that the sensor is suitable for operation in reflection mode. Through a series of dynamic measurements, the sensor is highly sensitive to object movement at subcentimeter distances with high repeatability. The sensor exhibits ultrafast microsecond response, and its real-time monitoring capability is also demonstrated by applying it to detect slight motions of moving objects at different frequencies, including the human heart rate, the vibration of the rotary pump, the oscillation of the speaker diaphragm, and the speed of the rotating disk. The compact and elegant integration scheme presented herein opens a new avenue for realizing a chip-scale proximity sensing device, making it a promising candidate for widespread practical applications.

中文翻译：

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超快小型化 GaN 基光电接近传感器

在这项工作中，提出了一种基于亚毫米尺寸 GaN 单片芯片的新型超快光电接近传感器。通过晶圆级微制造工艺制造，采用相同 InGaN/GaN 二极管结构的片上单元可以用作发射器和接收器。对片上单元的光电特性进行了深入研究，并验证了接收器响应发射器光强变化的能力，表明该传感器适合在反射模式下工作。通过一系列动态测量，传感器对亚厘米距离内的物体运动高度敏感，具有高重复性。该传感器表现出超快的微秒响应，其实时监测能力还通过应用它来检测运动物体在不同频率的轻微运动，包括人体心率、旋转泵的振动、扬声器振膜的振动和旋转速度磁盘。本文提出的紧凑而优雅的集成方案为实现芯片级接近传感设备开辟了一条新途径，使其成为广泛实际应用的有希望的候选者。