Numerical Investigation of Silicon Nitride Trench Waveguide
A detailed experimental and theoretical study of narrow ridge waveguides in glass films formed by ion-etching of patterns in photoresist has been carried out. Because the resultant waveguide profiles are trapezoidal a numerical approach, the finite-element method, has been used to compute theoretical dispersion curves. Experimental dispersion curves were obtained from measurements of output m-lines. Agreement between experiment and theory varies from moderately good to excellent over the range of waveguide profiles studied.