1.3 μm InGaAlAs asymmetric corrugationpitch- modulated DFB lasers with high mask margin at 28 Gbit/s

Direct modulation of a 1.3 μm InGaAlAs asymmetric corrugation-pitch-modulated (ACPM) distributed feedback (DFB) laser operated at 28 Gbit/s was experimentally demonstrated. The laser exhibits linear light-current characteristics and a high-frequency response with a small roll-off at low frequency compared with a conventional λ/4-shifted DFB laser. Moreover, it attains a high mask margin (20%) under 28 Gbit/s operation at 55°C. These superior properties are due to a superior ACPM grating that suppresses longitudinal spatial hole-burning.