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

• Main Authors: Xiaodan Pang (14288636), Toms Salgals (14288661), Hadrien Louchet (14288640), Di Che (14288642), Markus Gruen (14288644), Yasuhiro Matsui (14288663), Thomas Dippon (14288645), Richard Schatz (14288648), Mahdieh Joharifar (14288651), Benjamin Krüger (14288653), Fabio Pittala (14288654), Yuchuan Fan (14288657), Aleksejs Udalcovs (14288658), Lu Zhang (14288664), Xianbin Yu (14288665), Sandis Spolitis (14288668), Vjaceslavs Bobrovs (14288670), Sergei Popov (14288673), Oskars Ozolins (14288675)
• Format: Report
• Language: unknown
• Published: 2022
• Subjects: Components; Circuits; Devices and Systems; Communication; Networking and Broadcast Technologies; Photonics and Electrooptics; direct modulation; distributed-feedback laser; on-off keying (OOK); pulse amplitude modulation; DML
• Online Access: https://doi.org/10.36227/techrxiv.21762983.v1

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.