Uncooled 53-Gbaud PAM4 Operation of EA/DFB and Directly Modulated DFB Laser for 400GbE Applications

We have developed high speed Electro-Absorption modulator integrated DFB (EA/DFB) lasers and directly modulated DFB lasers for 400 GbE applications. An uncooled type $1.3-\boldsymbol{\mu} \mathbf{m}$ EA/DFB laser was demonstrated for 53-Gbaud PAM4 operation with 0.9 Vpp from 20 to 85°C. In addition, an uncooled $1.3-\boldsymbol{\mu} \mathbf{m}$ directly modulated DFB laser was operated for 53-Gbaud PAM4 (106-Gb/s) from 25 to 80°C with clear eye openings.