This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Glass Slab Waveguide - Parameters and Operation A slab waveguide consists of a lossless glass film of 10 . μm thickness with a re- fractive index of 1 . 515. This film is atop a lossless substrate with a refractive index of 1 . 500. The cover above the waveguide is air of refractive index 1 . 000. Light of freespace wavelength 1 . 55 μm is launched into the waveguide. The polarization of the launching light is such that it excites both TE and TM modes in the waveguide. These modes represent light that is totally internally reflected at the film-substrate boundary and at the film-cover boundary. In addition, the guided modes satisfy the electromagnetic boundary conditions. It is desired to characterize in detail the above waveguide and the TE 1 and TM 1 modes in the this waveguide. From Fresnel’s equations, the magnitude of the phase shifts upon total internal reflection at the film-substrate boundary are given by φ TE,f- s = 2 tan- 1 n 2 f sin 2 θ- n 2 s n f cosθ and φ TM,f- s = 2 tan- 1 n f n 2 f sin 2 θ- n 2 s n 2 s cosθ where θ is the zig-zag angle of the TE 1 guided mode (in first equation) or TM 1 mode (in second equation). Similarly, the magnitude of the phase shifts at the film-cover bound-second equation)....
View Full Document
- Spring '08
- Light, refractive index, Total internal reflection, group velocity