Abstract

In multigigabit optical-fiber transmission systems the wavelength chirping of the light source is an important factor limiting the transmission distance. A multiple-quantum-well (MQW) laser is a suitable light source for these systems because of its small wavelength chirping.¹ The wavelength chirping Δλ is expressed by the linewidth enhancement factor α (Δλ ∝ α), which depends on the structure of the quantum wells. To date, we have investigated the dependence of the differential gain and the K-factor on the number of quantum wells.² In this paper we indicate that the 2.5-Gbit/s transmission characteristics of large-dispersion fiber (1470 ps/nm) strongly depend on the number of quantum wells of the 1.55-μm MQW DFB LD’s, and we show the extremely low dispersion penalty (1.3 dB) at the threshold bias current as a result of well-number optimization.

© 1993 Optical Society of America