PURPOSE: To connect a measuring device to only one end of an optical fiber thereby to permit transmission band measurement to be performed, by detecting an optical pulse that is reflected from the other end propagates in the opposite direction within an optical fiber and emits from one end, and by evaluating the transmission band.
CONSTITUTION: A laser pulse light that is excited at a pulse generator 2 and outputted from a semiconductor 1 propagates via an optical direction coupler 3 and an exciter 7 inserted in order to excite mode distribution with good reproducibility in an optical fiber 8 to be measured. A part of the laser light reflected from the other end surface 9 of said fiber 8 propagates in the opposite direction through the fiber 8 and is detected by a detector 4. Further, by a sampling circuit 5 and an operation processing part 6, etc., the detected laser light pulse is subjected to Fourier transformation 6, and the 6dB band width of both ways is determined. Accordingly, only one end of an optical fiber is connected with a measuring device, and measurement for a transmission band is performed along with realization of easy calibration of transmitting and receiving devices, thereby allowing a highly accurate measurement to be performed.
TOKUDA MASAMITSU
HORIGUCHI TSUNEO
| JPS536059A | 1978-01-20 | |||
| JPS536047A | 1978-01-20 | |||
| JPS53140051A | 1978-12-06 |