Simultaneous optical monitoring and fiber supervising for WDM networks using an OTDR combined with concatenated fiber gratings

We have proposed a new optical monitoring technique that employs an optical time-domain reflectometer combined with an acoustooptic switch and concatenated fiber Bragg gratings to achieve simultaneous optical monitoring and fiber surveillance for wavelength-division-multiplexed (WDM) networks. The optical power monitoring with dynamic range of 26 dB and accuracy /spl les//spl plusmn/0.1 dB for each WDM channel and the feasibility of simultaneous optical monitoring and fiber surveillance in WDM networks have also been demonstrated by using this technique.