Low-loss waveguides for active-passive integration using impurity-free vacancy diffusion

Summary form only given. We report record low waveguide loss associated with large photoluminescence blue shifts obtained through impurity free vacancy diffusion (IFVD) of a unique Broadened Waveguide (BWG) GRINSCH-SQW. Waveguide loss as low as 0.41 dBcm/sup -1/ and room temperature photoluminescence (RTPL) blue shifts as large as 76 nm have been measured with this BWG structure. In this work, reduced free-carrier losses resulting from the BWG has yielded guided wave loss measurements averaging less than 2 dBcm/sup -1/ in material whose RTPL spectrum has been blue shifted 50 nm from the non-disordered material PL peak wavelength of 810 nm. In comparison, the lowest loss obtained with IFVD reported in literature was found to be 8.5 dBcm. IFVD provides a means of successfully integrating active-passive PICs in the GaAs/AlGaAs material system. However, the loss values of structures reported in literature are not acceptable for efficient integration. Out effort is focused on reducing loss of interconnecting waveguides applied to high-density integrated photonics while maintaining acceptable active device performance.