Survivable optical fiber architecture employing ultra-wavelength-insensitive switch and coupler

A new survivable fiber network architecture, active/passive routing architecture, is proposed and the main aspects of its performance are described. This architecture consists of an ultra-wavelength-insensitive switch as an active element and a wavelength-insensitive coupler as a passive element. The ultra-wavelength-insensitive switch is wavelength-independent from 1.25 to 1.6 μm. The survivable network was constructed by using the above routine elements and field-installed cables, and a switching experiment was carried out for WDM signals in the 1.3- and 1.55-μm bands. The bit-error-rate measurement proved that this fiber architecture can maintain high survivability for upstream and downstream signals by permitting a loss penalty of 0.5 dB. When a fiber fails, the signal is switched automatically to another fiber link, and signal synchronization was restored within 1 s