Low-bias current 10 Gbit/s direct modulation of GaInAsP/InP membrane DFB laser on silicon

Low-power consumption directly-modulated lasers are a key device for on-chip optical interconnection. We fabricated a GaInAsP/InP membrane DFB laser that exhibited a low-threshold current of 0.21 mA and single-mode operation with a sub-mode suppression ratio of 47 dB at a bias current of 2 mA. A high modulation efficiency of 11 GHz/mA^1/2 was obtained. A 10 Gbit/s direct modulation using a non-return-to-zero 2³¹-1 pseudo-random bit sequence signal was performed with a bias current of 1 mA, which is the lowest bias current ever reported for direct modulation of a DFB laser. A bit-error rate of 10^-9 was successfully achieved.