Stepped-height ridge waveguide MQW polarization mode converter monolithically integrated with sidewall grating DFB laser

TL;DR

This paper demonstrates a monolithically integrated polarization mode converter with a DFB laser at 1555 nm, achieving high polarization purity and conversion efficiency with simplified fabrication, advancing integrated photonic devices.

Contribution

First demonstration of a monolithic 1555 nm polarization mode converter integrated with a sidewall grating DFB laser using minimal fabrication steps.

Findings

Achieved >94% TE to TM polarization conversion efficiency.

Obtained 98.2% TM mode purity at specific injection current.

Simplified fabrication process reduces complexity and cost.

Abstract

We report the first demonstration of a 1555 nm stepped-height ridge waveguide polarization mode converter monolithically integrated with a side wall grating distributed-feedback (DFB) laser using the identical epitaxial layer scheme. The device shows stable single longitudinal mode (SLM) operation with the output light converted from TE to TM polarization with an efficiency of >94% over a wide range of DFB injection currents (IDFB) from 140 mA to 190 mA. The highest TM mode purity of 98.2% was obtained at IDFB=180 mA. A particular advantage of this device is that only a single step of metalorganic vapor-phase epitaxy and two steps of III-V material dry etching are required for the whole integrated device fabrication, significantly reducing complexity and cost.