12-THz frequency difference measurements and noise analysis of anoptical frequency comb in optical fibers

摘要

A span up to 50 THz of optical frequency comb (OFC) has beennobtained by self-phase modulation in an optical fiber. The coherentnnature of the process was verified by heterodyne-detecting the sidebandsnoffset by up to 12 THz from the carrier. The signal-to noise ratio (SNR)nof the beat signal between a sideband at 12 THz offset and anothernsingle-mode laser was 32 dB in a 1-MHz bandwidth. Although the linewidthnof each beat signal was maintained within a few megahertz, phase noisenpedestal power increased with the offset frequency