Abstract
We report the fabrication of multiple wavelength chips in InGaAs-InGaAsP laser structure using a novel ion implantation induced quantum-well (QW) intermixing technique. This technique first consists of using a gray mask photolithography and reactive ion etching process to create a SiO2 implant mask with variable thickness on the sample. This is followed by a single 360-keV phosphorus ion implantation at a dose of I x 10(14) cm(-2) at 200 degreesC, which creates different amounts of point defects in the sample depending on the local thickness of the SiO2 mask. A subsequent thermal annealing step induces QW intermixing through the diffusion of the point defects across the structure. With this technique, we have successfully fabricated 10-channel multiple wavelength laser diodes, with lasing wavelength spreading over 85 nm (between 1.47 and 1.55 mum), monolithically integrated on a single chip. Only a limited increase of threshold current density of 17% (i.e., from 1.2 to 1.4 kA/cm(2)), has been observed between the least intermixed and the most intermixed lasers.