Design of an omnidirectional single-point photodetector for large-scale spatial coordinate measurement

In high precision and large-scale coordinate measurement, one commonly used approach to determine the coordinate of a target point is to utilize the spatial trigonometric relationships between multiple laser transmitting stations and the target point. A light receiving device at target point is the key element in large-scale coordinate measurement systems. To ensure high-resolution and highly-sensitive spatial coordinate measurement, a high-performance and miniaturized omnidirectional single-point photodetector (OSPD) is highly desired. Here we report one design of OSPD using aspheric lens, which achieves enhanced reception angle of -5 to 45 degree in vertical and 360 degree in horizontal. As the heart of our OSPD, the aspheric lens is designed in geometric model and optimized by LightTools Software, which enables reflecting wide-angle incident light beam into the single-point photodiode. The performance of home-made OSPD is characterized with working distances from 1 m to 13 m and further analyzed utilizing established geometric model. The experimental and analytic results verify that our new device is highly suitable for large-scale coordinate metrology. The developed device also holds great potential in various applications such as omnidirectional vision sensor, indoor global positioning system, optical wireless communication systems.