Fujitsu achieves 40-Gbps optical-fiber transmission using directly-modulated laser
Directly modulated active distributed reflector distributed feedback lasers over wide temperature range operation (−40 to 85°C) Download: 709次 | Chinese Optics Letters -- 中国光学期刊网
Difference between Direct modulation vs External modulation
a) directly modulated laser (b) directly modulated laser with OIL | Download Scientific Diagram