The design principles and measurement results for a compact shallow etched distributed diffraction grating waveguide demultiplexer are presented. The deeply etched diffraction grating facets are replaced with a shallow etched odd-order quarter wavelength Bragg reflector to increase the Fresnel reflection coefficient. A prototype device was designed for coarse wavelength demultiplexing... https://parisnaturalfoodes.shop/product-category/lung/