Simulation of 3d nanophotonics device for coupling light into planar waveguide
A.G. Nalimov, A.A. Kovalev, V.V. Kotlyar, V.A. Soifer

Image Processing Systems Institute of the RAS,
Samara State Aerospace University

Full text of article: Russian language.

Using the FullWAVE software ( for solving Maxwell’s equations by the finite-difference FDTD-method, we simulate the performance of a three-dimensional nanophotonics device comprising a subwavelength diffraction grating, a wide and a narrow planar waveguide, and a photonic crystal (PhC) Mikaelian lens located in a thin silicon film coated on a substrate containing a three-period Bragg mirror, with each period made up of silicon + silica layer. The device is intended to couple a laser beam with the focal spot of 3 x 4.6µm2 and wavelength 1.55 µm into a planar waveguide of width 500 nm, resulting in a 125-fold “compression” of the input beam cross-section. The simulation has shown that the coupling efficiency amounts to 32% of the energy of the linearly polarized elliptic Gaussian beam focused onto the grating and 52% when a plane wave segment is incident onto the grating. For comparison, the grating-unaided coupling of light into the same device by the butt-coupling of light into the wide waveguide’s silicon film gives the efficiency as low as 8%.

Key words:
FDTD-method, photonic crystal lens, coupling two different waveguides, input light into waveguide, Bragg mirror, nanophotonics.


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