Generation of optical frequencies out of the frequency comb of a femtosecond laser for DWDM telecommunication

We exploit the frequency comb of a fs laser as the frequency ruler to generate reference optical frequencies for multi-channel DWDM (dense wavelength-division-multiplexing) telecommunication. Our fiber-based scheme of single-mode extraction enables on-demand generation of optical frequencies within the telecommunication band with an absolute frequency uncertainty of 9.1 x10(-13). The linewidth of extracted optical modes is less than 1 Hz, and the instability is measured 2.3x10(-15) at 10 s averaging. This outstanding performance of optical frequency generation would lead to a drastic improvement of the spectral efficiency for the next-generation DWDM telecommunication.