In order to realize tunable multichannel high sensitivity refractive index sensing. a square resonator connected with a Rectangular Groove (RG) is proposed to couple with the highly compact Metal-Dielectric-Metal (MDM) waveguide containing double metal baffles. The transmission spectrums of the proposed waveguide structure have been calculated by the finite element method. which exhib... https://jalyttlers.shop/product-category/photo-frame/