Are 1310 and 1550 optics comptatible ?
Can humans see ultraviolet light? These are two different wavelengths. The equipment is specifically designed and built to _not_ allow interaction between different wavelengths.
One can run 1310 and 1550 on the same fiber with WDM, but 1310 and 1550 won't talk to each other.
As someone already pointed out, the receivers are often wide enough to see both wavelengths. (Cheaper to build that way.) So it might work, depending on the loss and dispersion characteristics of the specific fiber installation. But I'd be surprised if Cisco would actually support that configuration... An WDM demultiplexer typically has a passive narrowband optical filter in front of the receiver to allow only the desired wavelength through. Steve