Electroabsorption modulator‐integrated distributed Bragg reflector laser diode for C‐band WDM‐based networks

• Published in: ETRI journal Vol. 45; no. 1; pp. 163 - 170
• Main Authors: Kwon, Oh‐Kee, Lee, Chul‐Wook, Kim, Ki‐Soo
• Format: Journal Article
• Language: English
• Published: Electronics and Telecommunications Research Institute (ETRI) 01.02.2023
• Subjects: 25 gb/s nrz; 50 gb/s pam-4; distributed Bragg reflector laser diode; electroabsorption modulator; wavelength division multiplexing; wavelength tuning
• ISSN: 1225-6463; 2233-7326
• DOI: 10.4218/etrij.2021-0284

We report an electroabsorption modulator (EAM)‐integrated distributed Bragg reflector laser diode (DBR‐LD) capable of supporting a high data rate and a wide wavelength tuning. The DBR‐LD contains two tuning elements, plasma and heater tunings, both of which are implemented in the DBR section, which have blue‐shift and red‐shift in the Bragg wavelength through a current injection, respectively. The light created from the DBR‐LD is intensity‐modulated through the EAM voltage, which is integrated monolithically with the DBR‐LD using a butt–joint coupling method. The fabricated chip shows a threshold current of approximately 8 mA, tuning range of greater than 30 nm, and static extinction ratio of higher than 20 dB while maintaining a side mode suppression ratio of greater than 40 dB under a window of 1550 nm. To evaluate its modulation properties, the chip was bonded onto a mount including a radiofrequency line and a load resistor showing clear eye openings at data rates of 25 Gb/s nonreturn‐to‐zero and 50 Gb/s pulse amplitude modulation 4‐level, respectively.