We propose a hybrid silicon-nitride (Si3N4 or SiN for short)/nonlinear polymer waveguide to achieve second-harmonic generation of an input 1550 nm signal by modal phase-matching between zero-order spatial mode at 1550 nm and second-order mode at 775 nm. We explore and optimize two cases. single channel waveguide and slot waveguide. by varying the waveguide dimensions. https://parisnaturalfoodes.shop/product-category/acidic-stomach-alkaline-balance/