Reconfigurable Position-Sensitive Detectors with In-Sensor Light Intensity Adaptability

Precise light spot position measurement under a range of illumination conditions is crucial for various applications such as industrial measurement, laser guidance, and free-space optical communication. However, conventional position-sensitive detectors suffer from inevitable photoresponse saturation under strong light, severely restricting their precision and dynamic range. Herein, a reconfigurable position-sensitive detector is proposed to realize high-precision light spot position measurement over a wide dynamic range. The device is based on an InGaAs/InP heterojunction and integrated with a metal-oxide-semiconductor structure to achieve active gate modulation of the lateral resistance and photoresponse characteristics of the device. The results demonstrate that in the scenario where strong light injection leads to increased light spot position non-linearity and measurement errors, the application of a gate voltage to induce a low-resistance lateral conductive channel can effectively improve the transport efficiency of photocarriers, thereby reducing the position non-linearity to ∼1% and restoring measurement accuracy. This design endows the position-sensitive detector with the capability of adaptive adjustment to the light intensity environment, providing a solution for developing near-infrared optoelectronic tracking systems with high precision and a wide dynamic range.