**Grado en Ingeniería de Tecnologías y Servicios de Telecomunicación**

*Pablo Sanchis Kilders*

INTRODUCTION: The effective index of a planar optical
waveguide is calculated by using a ray optics approach. The approach is based on numerically solving an equation that
takes into account the phase shift at the waveguide interfaces as well as from the propagation through the waveguide
core. The resulting equation can be easily solved by looking at the cross point between the left hand side (LHS) and right
hand side (RHS) terms. The RHS term will depend on the light polarization, TE or TM. The solution is given for a certain
theta angle that is then used to calculate the effective index by n1?sin(theta). OBJECTIVES: -Calculate the effective index
of the fundamental mode and higher order modes. -Calculate the range of waveguide thicknesses to have singlemode
transmission. -Analyze the influence of the refractive index contrast and light polarization depending on the symmetry of
the planar waveguide. INSTRUCTIONS: Set the refractive indices of the planar waveguide, the operation wavelength and
obtain the effective index for each polarization by changing the waveguide thickness.