Ultra-Narrow Asymmetric Filter forTransmission with0.8bit/s/Hz Spectral Efficiency

A novelapproach isproposed toultra-narrow optical filtering indenseWDM transmission. Thefilter based onfiber Bragggrating isspecially designed andfabricated tobe slightly asymmetric. A feasibility of8x4OGbit/s DWDM RZ transmission with0.8bit's/Hz spectral efficiency (without PDM andFEC)over1280kmofSMF/DCFlink hasbeenconfirmed bynumerical modelling. ©2005 Optical Society ofAmerica OCIScodes: 060.2340 Fiber optics components; 230.1480 Bragg reflectors 1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~(b) 05- o~~~~~~~rder orde y 42H ~~~~~~~~~~~~~~~-250 -200 -150 -100 -50 0 50 100 150 200 250 -40 030 -20 -10 0 10 20 00 40 50 0 Frequncy( GHz) Froc-eny (G14z1