  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.
