1 / 8

Chapter 6 OPTICAL FIBERS AND GUIDING LAYERS

Chapter 6 OPTICAL FIBERS AND GUIDING LAYERS. ◈ The dielectric slab guide (Waveguide) ▪ Wave equation (Governing eq.):. TIR. ▪ Solution:. ▪ Direction separation: TE & TM. Transverse Electric (TE) Modes (1/3). ▪ TE field: ▪ Wave equation (previous):

kayla
Download Presentation

Chapter 6 OPTICAL FIBERS AND GUIDING LAYERS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 6 OPTICAL FIBERS AND GUIDING LAYERS ◈ The dielectric slab guide (Waveguide) ▪ Wave equation (Governing eq.): TIR ▪ Solution: ▪ Direction separation: TE & TM

  2. Transverse Electric (TE) Modes (1/3) ▪ TE field: ▪ Wave equation (previous): ▪ We can get the Eigen-value equation: TIR Each eigenfunction has one eigenvalue associated with it, ie, eigenfunctions and eigenvalues come in pairs . ▪ Considering : ▪ For core, we select a symmetric solution:

  3. Transverse Electric (TE) Modes (2/3) ▪ To match the boundary condition, the impedance should be continuous (at the interface): moves toward the origin and intersections are lost ▪ All higher-order modes (m>0) have a cutoff  Waves are not guided below a certain critical frequency

  4. Transverse Electric (TE) Modes (3/3) -- Even -- Odd ▪ Let (Normalized term), then the previous solutions are represented as: - even case: - odd case: ▪ [Ex]Higher mode   r m=1 ▪ Graphical representation - Discrete # of the TE solutions (modes) - - Mode depends on the radius of the circle m=0 m=2

  5. Dispersion diagram for TE waves in dielectric guide Higher mode  Less β

  6. Numerical/Graphical representation ▪ Field profile of dominant mode for three different frequencies ▪ Dominant TE mode

  7. Additional comprehension for waveguide E(y) profile: n1=1.5, n2=1.495, d=10mm, l=1mm TE1 TE2 x Core Cladding Even function solution Odd function solution TE3 → E or energy penetrates (leaks) at the boundary Even function solution TIR backward and forward in x-direction: Standing wave case

  8. Additional comprehension for waveguide ▪ Confinement factor: G - How much power is confined within the core -- Even -- Odd - How does Gchange for different modes? n2 + + n1 r n2 ▪ Partitioning of input field into different guided modes. - Discrete modes  Summation of the solutions → Energy penetrates (leaks) at the boundary →

More Related