Uncooled clear-eye-opening operation (25 to 95°C) of 25.8/28-Gbps 1.3-µm InGaAlAs-MQW directly modulated DFB lasers

Properties on an uncooled 1.3-µm DML applicable for 100GbE/OTU4 based SMF interfaces are described. We demonstrated 25.8-Gb/s mask margins of more than 20% up to 85°C. Moreover, clear 28.0-Gb/s eye diagram was obtained at 95°C.