Reliability of an electro-absorption modulator integrated with a distributed feedback laser

There are few reports on the reliability of an electro-absorption modulator integrated with a distributed feedback laser (EA-DFB laser), although this is a very important photonic device in wavelength-division multiplexing (WDM) systems. We present the degradation modes in the EA-DFB laser, showing the lifetime is not determined by the degradation of the modulator but by that of the DFB laser, and then confirming the laser´s stability under long-term operation. The devices we tested consisted of an EA modulator and a DFB laser that were integrated with butt-joint technology. The active layer of the DFB laser and the absorption layer of the modulator were composed of InGaAsP wells and InGaAsP barriers and were buried in Fe-doped InP.