MOCVD-grown c-band InAs/InAlGaAs quantum dot laterally-coupled distributed feedback lasers

There is a need for increased bandwidth in long range data communication systems. One potential way of achieving this is to increase the number of channels in wavelength division multiplexing systems (WDMs) by using quantum dot distributed feedback (DFB) lasers as the single-mode emitters. This bandwidth increase is provided by inhomogeneous size broadening, which broadens the gain spectrum and therefore the range of accessible wavelengths. We have fabricated laterally-coupled DFB lasers on both conventional quantum well material and InAs/InAlGaAs quantum dot material grown using metal-organic chemical vapour deposition (MOCVD). We have achieved threshold currents of 150 mA and a SMSR exceeding 40 dB with a cavity length of 1 mm.