Abstract

The monolithic integration of lasers and modulators in InGaAsP/InP is an attractive approach for the manufacture of compact, low-chirp sources with low packaging cost for high bit rate fiber transmission systems. For the control of chirp, the use of an interferometric Mach-Zehnder (MZ) modulator provides more flexibility than modulation by electro-absorption [1]. Zucker el al. have demonstrated a MZ modulator integrated with a superposed DBR laser [2], and more recently Tambun-Ek et al. have reported a MZ integrated with an optical amplifier and a conventional DFB laser, fabricated by selective area growth [3], Although both of these implementations offer the advantage of a small number of growth steps, the designs of the MZ and laser active regions are mutually constrained. In contrast, integration by butt-coupling virtually eliminates design constraints, allowing the DFB laser and modulator active regions to be independently optimized with respect to the choice of the number of quantum wells, the quantum well and barrier compositions, the doping profiles, and the optical confinement factors.

© 1996 Optical Society of America