A method and a device for optically measuring a distance by emitting an
amplitude modulated and bundled optical signal and by receiving the
signal reflected from a target object. The modulation frequency is
continuously regulated by means of a regulating loop in such a manner
that between the emitted and the received signal a fixed phase difference
prevails that is independent of the distance. For reducing the circuitry
required for a distance evaluation circuit, while maintaining a high
accuracy and for increasing the attainable regulation speed, the
detection of the phase difference occurs with a phase comparator.