TM Polarized Microcylinder Laser with Engineered Band of Tensile Strained InGaAsP/InP Quantum Well

Tensile-strained InP-based quantum well wafers provide TM mode emission with high optical confinement in the wavelength-sized microcylinder, which introduces feasible way for nanophotonic integration. For the engineering of the band structure, we develop a plane wave expansion method to solve the Luttinger-Kohn Hamiltonian in the InGaAsP quaternary system. After calculation, the quantum well with 0.43% tensile strain is selected for 1510-nm wavelength emission. We fabricated a microcylinder with the radius of 15 μm connected with a 2-μm-wide output waveguide using the standard planar technology. The device lases under the room temperature continuous wave injection with the threshold current of 24 mA. The multilongitude mode appears frequently in the spectra due to a flat gain region, and the side mode suppression ratio higher than 30 dB can be obtained when the peak gain position coincides well with the mode wavelength.