A characteristic analysis of the laser range finder with various modulation frequencies

In the signal processing of phase demodulation, the maximum detecting distance and the sensor resolution are directly determined by the modulation frequency. To have higher resolution of distance in the laser range finder using the phase demodulation method, signal should be modulated with a high frequency. However, it is not easy to have higher resolution with long range detection. Because, the maximum detecting distance is restricted by the modulation frequency. It is advantageous to use a proper frequency which is suitable for the each purpose. Analytical and experimental results are presented to show how the modulation frequency affects to the results.