Low-loss waveguide fabrication using inductively coupled argon plasma enhanced quantum well intermixing in InP quantum well sample

The inductively coupled plasma enhanced quantum well intermixing (ICP-QWI) technology has been well established for tuning the bandgap of quantum well structure using argon plasma. This technology provides effective bandgap tuning capability (e.g., with quantum well bandgap shift as large as 104 nm in quantum well laser structure in InP substrate [1]), which is competent for implementing photonic integration. A differential bandgap shift of 86 nm with very small differential linewidth broadening of ∼3 Å was obtained by applying selective intermixing using SiO₂ mask layer. Photonics integration capability was demonstrated by the fabrication of the broad area extended cavity lasers and the fabricated passive waveguide has a measured loss of 2.98 cm^-1.