S-Band WDM Transmission Using PPLN-Based Wavelength Converters and 400-Gb/s C-Band Real-Time Transceivers

Abstract

SUMMARY Multi-band WDM transmission beyond the C+L-band is a promisingtechnologyforachievinglargercapacitytransmissionbyalimitednumberofinstalledfibers.InadditiontotheC-andL-band,wecanexpecttousetheS-bandasthenextband.Althoughthedevelopmentofoptical componentsfornewbands,particularlytransceivers,entailsresourcedis-persion,whichisoneofthebarrierstotherealizationofmulti-bandsystems, wavelengthconversionbytransparentall-opticalsignalprocessingenables new wavelength band transmission using existing components. Therefore, we proposed a transmission system including a new wavelength band such as the S-band and made it possible to use a transceiver for the existing band by performing the whole-band wavelength conversion without using a transceiver for the new band. As a preliminary verification to demonstrate multi-band WDM transmission including S-band, we investigated the application of a novel wavelength converter between C-band and S-band, which consists of periodically poled lithium niobate waveguide, to the proposed system. We first characterized the conversion efficiency and noise figure of the wavelength converter and estimated the transmission performance of the system through the wavelength converter. Using the evaluated wavelength converters and test signals of 64 channels arranged in the C-band at 75-GHz intervals, we constructed an experimental setup for S-band transmission through an 80-km standard single-mode fiber. We then demonstrated error-free transmission of real-time 400-Gb/s DP-16QAM signals after forward error correction decoding. From the experimental results, it was clarified thatthewavelengthconverterwhichrealizestheuniformlosslessconversioncoveringthewholeC-bandeffectivelyachievestheS-bandWDMtransmis-sion,anditwasverifiedthatthecapacityimprovementofthemulti-band WDMsystemincludingtheS-bandcanbeexpectedbyapplyingitincom-binationwiththeC+L-bandWDMsystem.