Patent ID: 8831422

Claim:
An apparatus for performing coherent optical time domain reflectometry, the apparatus comprising: a control unit configured to generate a first pulse signal and a second pulse signal which have a common period (T), wherein the second pulse signal lags behind the first pulse signal, wherein the common period (T) satisfies T≧t+2L/C, wherein t is a light source adjustment time of a continuous light laser device, L is a length of a fiber to be detected, and C is a propagation velocity of an optical wave in the fiber; a driving unit configured to generate a frequency change driving signal according to the first pulse signal; the continuous light laser device configured to generate continuous light having a time-varying frequency and a frequency spectrum width that remains constant, wherein the continuous light laser device is driven by the frequency change driving signal; and a probe pulse generating unit configured to generate a probe pulse by modulating the continuous light according the second pulse signal.