Ruthenium-doped InP buried 1.3-/spl mu/m DFB lasers on a p-type substrate

We have fabricated 1.3-/spl mu/m InGaAsP DFB lasers with a simple buried structure using Ru-doped semi-insulating InP on a p-InP substrate for the first time. SIMS measurements revealed that the Ru-doped InP decreased Zn diffusion from the p-InP substrate in comparison with Fe-doped InP. The Ru-InP buried lasers showed good L-I characteristics and small-signal responses in a temperature range of 25 to 95 /spl deg/C. Clearly opened eyes for 10-Gb/s direct modulation of the Ru-InP buried lasers were obtained even at 85 /spl deg/C.