| 摘要 |
Previous efforts to measure polarization dependent loss of optical components have been limited in uncertainty to more than 0.01 dB. This is because the power meter used in a test set contains polarization dependent loss which adversely affects the final readings. It is here disclosed that an unpumped erbium doped fiber (36) can convert a received polarized signal into unpolarized amplified spontaneous emission of a longer wavelength if the fiber is of sufficient length to absorb the received signal. By locating the inventive unpumped erbium doped fiber upstream of the power meter (38) of a test set, the polarized signal to the power meter is converted to an unpolarized signal and, therefore, the polarization dependent loss of the power meter can not influence the measurement obtained. <IMAGE> |
