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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 24 — Nov. 19, 2012
  • pp: 26766–26777

Refractive index profiling of an optical waveguide from the determination of the effective index with measured differential fields

Wan-Shao Tsai, San-Yu Ting, and Pei-Kuen Wei  »View Author Affiliations

Optics Express, Vol. 20, Issue 24, pp. 26766-26777 (2012)

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The evanescent tails of a guiding mode as well as its first and second derivatives were measured by a modified end-fire coupling method. The effective index of the waveguide can be obtained by simultaneously fitting these three fields using single parameter. Combined with an inverse calculation algorithm, the fields with fitted evanescent tails showed great improvement in the refractive index profiling of the optical waveguide, especially at the substrate region. Single-mode optical fibers and planar waveguides of proton-exchanged (PE) and titanium-indiffusion (Ti:LiNbO3) on lithium niobate substrates with different refractive index profiles were measured for the demonstration.

© 2012 OSA

OCIS Codes
(070.0070) Fourier optics and signal processing : Fourier optics and signal processing
(100.3190) Image processing : Inverse problems
(130.3730) Integrated optics : Lithium niobate
(230.7390) Optical devices : Waveguides, planar
(290.3030) Scattering : Index measurements

ToC Category:
Integrated Optics

Original Manuscript: September 5, 2012
Revised Manuscript: October 26, 2012
Manuscript Accepted: October 29, 2012
Published: November 13, 2012

Wan-Shao Tsai, San-Yu Ting, and Pei-Kuen Wei, "Refractive index profiling of an optical waveguide from the determination of the effective index with measured differential fields," Opt. Express 20, 26766-26777 (2012)

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