Frank, from the avnx thread, Jack:
Andy, surely you don't believe that Leaf Fiber literally means one simply strings together so-called "zero dispersion" fiber and there is zero dispersion! and thus the wave would travel around the world keeping its form and carrying the data! somehow one must keep the wave's form, and the fiber alone (at least today's fiber, even LEAF) can't do it. so you need either DCF like LEAF, plus a powerful (i might say SHOCKED) wave, e.g. solitons, RZ or quasi solitons, plus forward error correction - all to overcome the regeneration now necessary by Optical-Electronic-Optical devices. and all methods - including avnx's - need amplifiers. avnx's virtually imaged phased array can tune the wave, and there seems to be no optical nonlinearity. those are the key advantages. the part that i'm not satisfied with - it may be my ignorance - is that an important aspect of the tuning is mechanical - a moving part - and these moving parts need constant adjustment to, in this case, very fine tolerances. Murphy's Law plays hob with moving parts. if someone here can respond to this last point - say Frank Coluccio - i'd be very appreciative. Jack
BTW The original invention is by M. Shirasaki, "Chromatic-dispersion compensator using virtually imaged phased array",
IEEE Phot. Tech. Lett., vol.9 no.12, December 1997. |
