Contact reflectivity effects on thin p-clad InGaAs single quantum-well lasers

Thin p-clad InGaAs quantum-well (QW) lasers with either Au or Ni as the p-contact metal have been fabricated. Due to reduced contact reflectivity, the Ni contact lasers hare significantly higher threshold currents and lower slope efficiencies than the Au contact lasers. In addition, operating wavelength differences greater than 50 mn are observed for cavity lengths between 250 and 700 microns, with large wavelength jumps occurring at shorter and longer cavity lengths. The measured wavelength effects are explained by incorporating the optical mode loss difference between the two laser types into quantum-well laser theory.>