The present invention relates to the field of communication transmission, and in particular, to a method for generating a probe pulse and a coherent optical time domain reflectometer. The coherent optical time domain reflectometer includes: a control unit, configured to generate a first pulse signal and a second pulse signal which have a same period T, where the second pulse signal lags behind the first pulse signal, and the period T of the first pulse signal and of the second pulse signal satisfies T‰¥t+2L/C; a driving unit, configured to generate a frequency change driving signal according to the first pulse signal; a continuous light laser device, configured to generate, as driven by the frequency change driving signal, continuous light which has a changing frequency and an unchanging frequency spectrum width; and a probe pulse generating unit, configured to modulate the continuous light according to the second pulse signal to generate a probe pulse. The coherent optical time domain reflectometer provided in embodiments of the present invention has high fiber fault resolution and location accuracy.
METHOD FOR GENERATING PROBE IMPULSE AND COHERENT OPTICAL TIME DOMAIN REFLECTOMETER