1.3 µm gain coupled DFB laser with InGaAlAs MQW grown on absorptive InGaAsP corrugation

Abstract

An InGaAlAs multiquantum well (MQW) has been successfully overgrown on the absorptive InGaAsP corrugation for fabricating the 1.3 µm gain coupled distributed feedback (DFB) lasers. The absorptive InGaAsP corrugation was efficaciously preserved during the overgrowth of the InGaAlAs MQW active region. The absorptive InGaAsP corrugation has a relatively high intensity around the PL peak wavelength in comparison with that of the InGaAlAs MQW. The fabricated DFB laser exhibited a side mode suppression ratio of 40 dB together with a high single-mode yield of 90%.

Integratable and High Speed Complex-Coupled MQW-DFB Lasers Fabricated on Semi-Insulating Substrates

“…Two types of structures have been developed to incorporate the gain-coupling mechanism: a gain-coupling structure [9] and a loss-coupling structure. [10,11] It is difficult to realize a pure gain-or loss-coupling structure because of material growth, processing limitations and actual carrier-induced index effects in the device. An alternative approach is to use a complex gain-coupling mechanism [12] to improve laser performance without sacrificing manufacturability and device reliability.…”

“…A sinusoidal grating profile is enough to reach the coupling efficiency 𝜅𝐿 of 2-3 in order to reach high-yield singlemode operation. [11,13] Finally, a 150 nm p-InP layer, 20 nm etching stop layer, 1.8 µm p-InP cladding layer and 200 nm p-InGaAs contact layer were successively grown on the corrugation. The right part of Fig.…”