| 摘要 |
An evaluation device, measuring arrangement and method for path length measurement. The evaluation device for path length measurement is configured to evaluate a measured signal which represents an intensity of a sequence of pulses of electromagnetic radiation as a function of time. The sequence of pulses has a repetition rate. The evaluation device is configured to determine a phase difference between a component of the measured signal, the component oscillating with a frequency, and a reference signal which oscillates with the frequency. For this purpose, the evaluation device generates, for example by frequency mixing, a first signal and a second signal which have another phase difference, such that the first signal and the second signal each oscillates with another frequency which is different from said frequency, and that the other phase difference has a predetermined relation to the phase difference.
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