Ion Implanted GaAshnGaAsLateral Injection Ridge QW Laser
for QEICs: Study of Operation Mechanisms
A.A. Tager', R. Gaska', I.A. Avrutsky', M. Fay', H. Chik', A. SpringThorpe3,Z. Husain3,J.M.
Xu', and M. Shur4
'University of Toronto,Dept. of Electrical& ComputerEngineering,Toronto,Ontario,M5S 1A4,Canada.
'University of Virginia, Dept. of Electrical Engineering, Charlottesville, VA; currently with APA Optics Inc.,
3NortelTechnology,Nepean, Ontario, Canada.
4RensselaerPolytechnicInstitute,Dept. Electrical,Computer,and SystemsEngineering,Troy, NY.
Abstract. We have fabricated and characterized lateral current injection (LCI) ridge-waveguide lasers with
implanted contacts. Comprehensive optical and electrical measurements have been performed over a wide
temperature range (10K to 300K) on two sets of lasers with differing ridge widths and active region structures.
Several new phenomena unique to the LCI mechanism have been observed and explained, including a positive
differential resistance kink at threshold, and an inverse temperature-dependence of quantum efficiency and
threshold current at cryogenic values. Electrodhole mobilitydisparity,local carrier non-pinning above threshold
due to photon-assisted carrier diffusion, and intrinsically higher current densities have been experimentally
identified as the major factors governing LCI laser characteristics. The results have important implications for
optimum LCI laser design and ultimateperformance.
The lateral current injection (LCI) laser, with n andp contacts on the same side of the wafer and current