Abstract

In optoelectronic or photonic integrated circuits (OEICs, PICs), lasers that can be processed·with precise control of the waveguide structure and metal contacts to achieve good performance and high yield are important. By using a self-aligned reactive ion etching and selective wet chemical etching combination, we have fabricated InGaAs/InGaAsP strained SQW polyimide-buried ridge guide lasers with very low internal waveguide losses.¹ This laser structure has demonstrated near 100% yields of Fabry-Perot MQW laser chips grown by chemical beam epitaxy.² High bandwidth operation (20 GHz) has also been reported for InGaAs/GaAs MQW lasers fabricated with the polyimide-buried ridge guide structure.³ Recently, we have demonstrated a 5-Gbit/s OEIC transmitter comprising a polyimide-buried self-aligned ridge guide Fabry-Perot laser and an HBT driver circuit.⁴ In this paper, we report, we believe for the first time, the use of the polyimide-buried self-aligned ridge guide structure for distributed feedback (DFB) lasers. The 1.55-μm strained MQW DFB lasers were grown by two-step metalorganic vapor phase epitaxy (MOVPE). Low threshold currents (near 10 mA) and single-mode output with >40 dB side-mode suppression were demonstrated. These high performance DFB lasers may be attractive for OEIC/PIC technologies in the future.

© 1992 Optical Society of America