Fabrication and characterization of complex-coupled MQW-DFB laser with an InGaAs absorptive grating

We have demonstrated successful operation of 1.55 mu m complex-coupled mult i quantum well (MQW) DFB lasers over a wide temperature range. This is acco mplished by using an InGaAs grating that absorbs the DFB emission. The use of Fe doped semi-insulated grating, in particular, facilitates the performa nce development compared with the normal conductive InGaAs grating. The per formance of these lasers has shown that the additional good characteristics of large mode size to the general advantages of high single-mode yield and narrow spectral linewidth in the gain-coupled DFB laser.