Novel opportunities for optical level gauging and 3D-imaging with the photoelectronic mixing device

The novel photoelectronic mixing device (PMD) possesses a variety of unique characteristics that open up new fields for optical distance measurement technology. PMD devices for the first time allow the use of straightforward modulation and system concepts previously constrained to radar and ultrasonic systems. This paper first reviews the PMD principle and then points out the differences between conventional optical systems and PMD systems. The requirements of two different applications, level gauging, and three-dimensional object position measurement are discussed. Suitable system concepts are introduced and verified with experiments. The results prove the feasibility of single-pixel sensors capable of high accuracy and multitarget resolution as well as low-cost three-dimensional imaging systems.