Ion-implanted GaAs-InGaAs lateral current injection laser

We have fabricated and characterized lateral current injection (LCI) ridge-waveguide lasers formed by ion-implanted injectors. Comprehensive optical and electrical measurements have been performed over a wide temperature range (10 K-300 K) on two sets of lasers with differing ridge widths and active region structures. Several new phenomena unique to the LCI mechanism have been observed, including a positive differential resistance kink at threshold, and inverse temperature-dependencies of quantum efficiency and threshold current at cryogenic temperatures. Electron-hole mobility disparity, local carrier nonpinning above threshold due to photon-assisted ambipolar diffusion, and intrinsically higher current densities have been identified as the major factors governing these LCI laser characteristics. The results have important implications for future LCI laser design and ultimate performance.