Optical spectral reshaping for directly modulated 4-pulse amplitude modulation signals

• Published in: 2017 19th International Conference on Transparent Optical Networks (ICTON)
• Main Authors: Ozolins, Oskars, da Ros, Francesco, Cristofori, Valentina, Pang, Xiaodan, Schatz, Richard, Chaibi, Mohamed, E, Bramerie, Laurent, Popov, Sergei, Galili, Michael, Oxenløwe, Leif Katsuo, Peucheret, Christophe, Jacobsen, Gunnar
• Other Authors: Acreo Swedish ICT AB, DTU Fotonik - Department of Photonics Engineering, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), KTH Royal Institute of Technology Stockholm (KTH ), Institut des Fonctions Optiques pour les Technologies de l'informatiON (FOTON), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS), European Project: 619626,EC:FP7:ICT,FP7-ICT-2013-11,SEQUOIA(2013)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2017
• Subjects: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic; DML
• Online Access: https://hal.science/hal-01578313; https://doi.org/10.1109/ICTON.2017.8024895

International audience The tremendous traffic growth in intra/inter-datacenters requires low-cost high-speed integrated solutions. To enable a significantly reduced footprint directly modulated lasers (DMLs) have been proposed instead of large external modulators. However, it is challenging to use DMLs due to their low dispersion tolerance and limited achievable extinction ratio (ER). A promising solution to this problem is optical spectral reshaping (OSR) since it is possible to increase the dispersion tolerance as well as to enhance the achievable ER for both on-of-keying and 4-pulse amplitude modulation (PAM) signals. However, moving to 4-PAM, many of the impressive demonstrations reported so far rely heavily on off-line digital signal processing (DSP), which increases latency, power consumption and cost.In this talk, we report on (i) a detailed numerical analysis on the complex transfer function of the optical filter for optical spectral reshaping in case of pulse amplitude modulation and (ii) an experimental demonstration of real-time dispersion-uncompensated transmission of 10-GBd and 14-GBd 4-PAM signals up to 10- and 26-km SSMF. This is achieved by combining a commercial 10-Gb/s DML with optical spectral shaping, thus removing the need for any complex off-line DSP and improving dispersion tolerance. These achievements are enabled by OSR based on a passive microring resonator fabricated on the SOI platform [4]. Significant improvement in receiver sensitivities was observed for both a 10-GBd signal after 10-km SSMF transmission and 14-GBd with no penalty after 26-km SSMF transmission.