APPARATUS AND METHOD FOR MEASURING OPTICAL FIBER TRANSMISSION BAND

摘要

PURPOSE:To obtain a transmission band measuring apparatus which enables a quick measurement at one end of an optical fiber to be measured, by making an optical pulse incident into the optical fiber being measured to perform a frequency analysis processing of the waveform of the optical pulse returned to an incident end thereof after reflected at the farther end thereof. CONSTITUTION:An optical pulse generating section 12 generates an optical pulse to be optically coupled to an optical fiber f1 to be measured and an optically directive coupler 3 optically separates the optical pulse returned to the incident end of the optical fiber f1 after reflected at the farther end thereof. A light receiving/analyzing section 13 receives the optical pulse separated and performs a frequency analysis of the waveform thereof. On the other hand, a pulse propagation time computing section 10 measures the two-way propagation time of the optical pulse and a delay circuit section 9 automatically sets the two-way propagation time measured by the computing section 10 while providing a trigger pulse delayed by the time to the light receiving/analyzing section 13. Then, a system control section 11 controls the entire operation as mentioned above. This enables the measurement and computation of the propagation time of the reflected optical pulse reciprocating through the optical fiber f1 thereby determining the starting time of taking in and processing the waveform of the optical pulse to be analyzed based on the propagation time thus obtained.