ch-3 optical waveguide

[optoelectronics] ch-3 optical waveguideOPTICAL WAVEGUIDES

Division of Electrical and Computer Engineering Hanyang University http://oeic.hanyang.ac.kr

COMMUNICATION RESEARCH LAB.

3-LAYER SLAB WAVEGUIDE



nc ≤ ns < n f nc = ns : Symmetric Waveguide nc > ns : Asymmetric Waveguide

COMMUNICATION RESEARCH LAB.

GUIDING CONDITION


sin θ > sin θ s ≥ sin θ c ns θ s = sin nf
1



,

nc θ c = sin nf
1





sin θ < sin θ s ≤ sin θ c : Radiation modes sin θ c < sin θ ≤ sin θ s : Substrate modes sin θ c ≤ sin θ s ≤ sin θ : Guided modes

COMMUNICATION RESEARCH LAB.

r DECOMPOSITION of k f


r cos θ + z sin θ ] k f 1 = k0 n f [x r cos θ + z sin θ ] k f 2 = k0 n f [ x
Longitudinal Propagation Constant



β = k0 n f sin θ



Transverse Wave Number

κ x = k0 n f cos θ =

(k0n f )2 β 2

COMMUNICATION RESEARCH LAB.

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