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Writing Bragg Gratings in Multicore Fibers
Published on: April 20, 2016
The impact of laterally coupled grating microstructure on effective coupling coefficients
R Millett1, K Hinzer, A Benhsaien
1Centre for Research in Photonics, University of Ottawa, Ottawa, ON, Canada.
Nanotechnology
|March 9, 2010
Summary
Fabrication of distributed feedback lasers is simplified using lithography and higher-order gratings. Tailoring grating microstructure enhances effective coupling coefficients, improving laser performance and matching simulations with experimental data.
Area of Science:
- Semiconductor device fabrication
- Photonics and optical engineering
- Materials science for optoelectronics
Background:
- Distributed feedback (DFB) lasers traditionally require complex regrowth steps for grating fabrication.
- High refractive index contrast gratings on waveguide ridges offer a fabrication-friendly alternative.
- Accurate numerical simulations are crucial for optimizing DFB laser design, necessitating precise modeling of radiating partial waves.
Purpose of the Study:
- To investigate the use of lithographic fabrication for higher-order gratings in DFB lasers.
- To modify the coupled-mode approach for accurate 2D cross-section analysis of various grating shapes.
- To determine effective coupling coefficients for different grating orders and microstructures.
Main Methods:
- Lithographic fabrication of laterally coupled gratings with high refractive index contrast.
- Modification of the coupled-mode approach to incorporate 2D cross-sectional effects.
- Analysis of rectangular, sinusoidal, triangular, and trapezoidal grating shapes.
- Determination of effective coupling coefficients for first to third-order gratings.
Main Results:
- Tailoring grating microstructure can double the effective coupling coefficient compared to standard gratings.
- Predicted effective coupling coefficient from fabricated grating microstructure shows excellent agreement with experimental data.
- The modified coupled-mode approach accurately predicts grating performance.
Conclusions:
- Lithographic fabrication of higher-order gratings simplifies DFB laser manufacturing by eliminating regrowth steps.
- Optimized grating microstructures significantly enhance coupling efficiency, improving laser performance.
- Accurate 2D simulations are vital for reliable DFB laser design and validation.
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