Effect of injection current on the dielectric constant of an inbuilt waveguide in twin-transverse-junction stripe lasers

An investigation has been made of the role of injected carriers in reducing the effective dielectric constant of the inbuilt waveguide of a (GaAl)As double-heterostructure twin-transverse-junction (t.t.j.) stripe laser fabricated by deep Zn diffusion. The technique employed in this study is the measurement of the spectral shift of each Fabry-Perot mode as a function of drive current. The results show that the injected carriers contribute (¿¿)c=¿5.92=10¿2 to the effective dielectric constant of the waveguide at threshold.