1.55 /spl mu/m absorptive-grating complex-coupled distributed feedback lasers with high single-longitudinal-mode yield

1.55 /spl mu/m InGaAsP/InP complex-coupled distri buted feedback lasers with p-InGaAs absorptive grating were demonstrated. With coupling strength of 1.77, single mode yield more than 70 % and side mode suppression ratio as high as 43 dB above two times threshold current were achieved. It has been verified that the presence of gain-coupling strength can eliminate the mode degeneracy effectively.