Measurements of dg/dN and dn/dN and their dependence on photon energy in λ =1.5μm InGaAsP laser diodes

Abstract

The first measurements of the dispersion of dg/dN and dn/dN, the variation in the gain and refractive index with injected carrier concentration, are reported for λ = 1.5 μm InGaAsP laser diodes. Particular attention has been paid to the accurate evaluation of the injected carrier concentration N through the direct measurement of the carrier lifetime coupled with the use of the ridge-waveguide laser structure, which benefits from real-index lateral waveguiding, together with low parallel leakage currents and low parasitic capacitance. The values of dg/dN and dn/dN, at the lasing wavelength, were determined to be 2.7 × 10 -16 cm 2 and - 1.8 × 10 -20 cm 3 respectively.