Suspended InGaAs Sub-Wavelength Grating Cladding Waveguide for Monolithic Integration with Quantum Cascade Lasers and Detectors for Mid-Infrared On-Chip Gas Sensing

Fully suspended InGaAs membrane sub-wavelength grating cladding waveguides (SWWs) are designed and fabricated for mid-infrared ammonia sensing at X=6.15pm in the InGaAs- InP platform considering monolithic integration of quantum cascade devices with 84 ppb estimating sensitivity.