LASING WAVELENGTH OF A GAAS INJECTION LASER

Combining the spectral function of the stimulated emission and the basic I-V characteristics of the GaAs laser, the relations among the lasing wavelength, the threshold current density and the impurity concentration are deduced. The lasing wavelength increases with increasing impurity concentration in the active region due to the effective shrinkage of the energy gap and with the decreasing threshold current density. Assuming the same concentration of the p-type impurity in the active layer as that of the n-type impurity in the substrate, the effective energy gaps EGeff of 1·4670, 1·4565 and 1·4375 eV are obtained for impurity concentrations of 1·1×1018, 3×1018 and 5×1018 cm-3 at 77°K, respectively. The observed temperature dependence of the lasing wavelength in the range from 77 to 200°K is in good agreement with our theory. © 1968.