Authors:
Abdorreza Torabi
and
Amir Ahmad Shishegar
Affiliation:
Sharif University of Technology, Iran, Islamic Republic of
Keyword(s):
Optical Waveguide End-facet, Guided Mode Reflection Coefficient, Characteristic Green’s Function, Complex Images Method, Rational Function Fitting Method, VECTFIT Algorithm, Optimization.
Related
Ontology
Subjects/Areas/Topics:
Computational Optical Sensing and Imaging
;
Lasers
;
Optical Communications and Networking
;
Optics
;
Optoelectronics
;
Photonic and Optoelectronic Materials and Devices
;
Photonic in Communications and Switching
;
Photonics
;
Photonics, Optics and Laser Technology
;
Semiconductor Lasers and Leds
;
Waveguide Lasers
Abstract:
A novel method for computation of modal reflectivity at optical waveguide end-facet is presented. The method
is based on the characteristic Green’s function (CGF) technique. Using separability assumption of the structure
and rational function fitting method (RFFM), a closed-form field expression is derived for optical planar
waveguide. The uniform derived expression consists of discrete and continuous spectrum contributions which
denotes guided and radiation modes effects respectively. An optimization problem is then defined to calculate
the exact reflection coefficients at the end-facet for all extracted poles obtained from rational function fitting
step. The proposed CGF-RFFM-optimization offers superior exactness in comparison with the previous reported
CGF-complex images (CI) technique due to contribution of all components of field in the optimization
problem. The main advantage of the proposed method lies in its simple implementation as well as precision
for any refractive index
contrast. Excellent numerical agreements with rigorous methods are shown in several
examples.
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