Paper
15 March 2016 SWG-designed MMI waveguides for dual and multi-beam splitting, beam position-shifting, and focusing purposes
Author Affiliations +
Proceedings Volume 9753, Optical Interconnects XVI; 97531B (2016) https://doi.org/10.1117/12.2212178
Event: SPIE OPTO, 2016, San Francisco, California, United States
Abstract
In this research, subwavelength grating (SWG) nanostructures with different periodic configurations are designed on a slab dielectric waveguide and theoretically studied for creating beam splitting, position-shifting, and focusing effects, using Comsol Multiphysics as the simulation tool. Su8 with a refractive index (n) of 1.585 is considered as the core material for the dielectric waveguide, which has a lateral and longitudinal dimension of 3 and 6 um, respectively. Uniform and nonuniform rows and columns of nanoholes with diameters of 90 nm are considered as the diffractive design elements. We took advantage of the multimode interference (MMI) phenomenon caused by periodic arrays of nanoholes as SWG structures, which are engineered to induce the desired effects. The power transmission efficiencies of the SWG-designed MMI waveguides are calculated in the wavelength range of 500-1200 nm. The efficiencies are high for the major part of the studied spectrum and reach a maximum of ~97% at 1200 nm for some designs. Also, the refractive index contrasts between the effective index (neff) and the ideal parabolic model (npar) are shown for the conventional MMI SU8 waveguide within a wavelength range of 700-1000 nm. It can be clearly seen that the contrast is minimum for λ = 700nm, and increases with wavelength, showing the multimode interference effect is optimum at 700 nm and deteriorates as the wavelength increases. Modal phase error (MPE) estimated for m=5 and different wavelengths revealed that the MMI device can have a fairly high performance within the whole studied wavelength range for a maximum mode number of 3. Additionally, the field intensity distributions calculated for the design with the beam splitting effect for different wavelengths reflected that the effect has a broadband characteristic.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
M. Abdolahi, H. Jiang, and B. Kaminska "SWG-designed MMI waveguides for dual and multi-beam splitting, beam position-shifting, and focusing purposes", Proc. SPIE 9753, Optical Interconnects XVI, 97531B (15 March 2016); https://doi.org/10.1117/12.2212178
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Waveguides

Brain-machine interfaces

Beam splitters

Refractive index

Dielectrics

Multimode interference devices

Wave propagation

RELATED CONTENT

Graded index MMI and its application in optical communications
Proceedings of SPIE (September 08 2011)
MMI splitters by ion-exchange in glass
Proceedings of SPIE (March 24 2000)
The modeling of MMI devices
Proceedings of SPIE (February 24 2006)
Optical waveguides for on-chip optical interconnects
Proceedings of SPIE (July 01 2004)

Back to Top