Abstract

The carrier-induced index change is important for the design of modulators and for the analysis of frequency-chirping effects, spectral linewidth, and wavelength-tuning characteristics. Until recently, only the index change for injected carrier density just near lasing threshold (N ≥ 0.8N_th) was known.¹ Thus the reported index change is valid only for carrier densities near N_th. Therefore a nonlinear relationship between index change and carrier density cannot be easily recognized for a small range of carrier density. In our previous publication,² an injection-reflection technique for measuring the Fabry-Perot oscillation was combined with a differential carrier-lifetime measurement for determining the carrier-induced index change over a wider range of carrier density (2 × 10¹⁷ to 2 × 10¹³ cm^-3).

© 1994 Optical Society of America