Intensity-based laser distance measurement system using 2D electromagnetic scanning micromirror

In this research, we present the feasibility testing results of a simple distance measurement system using microfabricated scanning micromirrors. Two different configurations have been tested with different types of micromirrors. In the first configuration, Lissajous scan pattern has been generated with horizontal scan frequency of 715 Hz, and the intensity of the laser beam reflected from the object has been measured with avalanche photodiode to estimate the distance. The position of the beam has been tracked using a separate position sensitive detector. Signals from both sensors are synchronized by eliminating the signal delay, which enables the detection of the distance of a specific point in the 2-dimensional scan pattern. In the simplified configuration, faster scanning micromirror with horizontal scan frequency of 28.8 kHz has been used to increase the resolution and position sensitive detector has been removed from the system by synchronizing the driving current waveform with the avalanche photodiode signals. Distance measurement from 20 to 50 cm has been demonstrated with the developed system.