200 Gb/s Optical-Amplifier-Free IM/DD Transmissions using a Directly Modulated O-band DFB+R Laser targeting LR Applications

• Main Authors: Pang, Xiaodan, Salgals, Toms, Louchet, Hadrien, Che, Di, Gruen, Markus, Matsui, Yasuhiro, Dippon, Thomas, Schatz, Richard, Joharifar, Mahdieh, Krüger, Benjamin, Pittala, Fabio, Fan, Yuchuan, Udalcovs, Aleksejs, Zhang, Lu, Yu, Xianbin, Spolitis, Sandis, Bobrovs, Vjaceslavs, Popov, Sergei, Ozolins, Oskars
• Format: Other/Unknown Material
• Language: unknown
• Published: Institute of Electrical and Electronics Engineers (IEEE) 2022
• Subjects: DML
• Online Access: http://dx.doi.org/10.36227/techrxiv.21762983; https://ndownloader.figshare.com/files/38620538

We experimentally demonstrate an O-band single-lane 200 Gb/s intensity modulation direct detection (IM/DD) transmission system using a low-chirp, broadband, and high-power directly modulated laser (DML). The employed laser is an isolator-free packaged module with over 65-GHz modulation bandwidth enabled by a distributed feedback plus passive waveguide reflection (DFB+R) design. We transmit high baud rate signals over 20-km standard single-mode fiber (SSMF) without using any optical amplifiers and demodulate them with reasonably low-complexity digital equalizers. We generate and detect up to 170 Gbaud non-return-to-zero on-off-keying (NRZ-OOK), 112 Gbaud 4-level pulse amplitude modulation (PAM4), and 100 Gbaud PAM6 in the optical back-to-back configuration. After transmission over the 20-km optical-amplifier-free SSMF link, up to 150 Gbaud NRZ-OOK, 106 Gbaud PAM4, and 80 Gbaud PAM6 signals are successfully received and demodulated, achieving bit error rate (BER) performance below the 6.25%-overhead hard-decision (HD) forward-error-correction code (FEC) limit. The demonstrated results show the possibility of meeting the strict requirements towards the development of 200Gb/s/lane IM/DD technologies, targeting 800Gb/s and 1.6Tb/s LR applications.