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Форма 502. КРАТКИЙ НАУЧНЫЙ ОТЧЕТ НА АНГЛИЙСКОМ ЯЗЫКЕ
Номер проекта12-07-00018
Руководитель проектаTsarev Andrei Vladimirovich
Название проектаEfficient transmission of optical wave through the crossed silicon wires by forward and
reverse tunneling to the adjacent waveguide
Год представления отчета2013
Вид отчетаэтап 2012 года
АннотацияThe paper deals with the problem of the crossing of the high index contrast channel optical
waveguides, by the example of thin silicon photonic wires in silicon-on-insulator. To solve the problem the new
structure is proposed. It is based on vertical tunnel coupling of thin tapered wire with a thick polymer optical
waveguide separated by a thin oxide layer. General three-dimensional problem we have reduced to two
interconnected two-dimensional, and for each we use different methodological approaches.The first part
corresponds to the gap of silicon wire, at which the tunneling energy (through the oxide layer) in the upper
wide polymer channel waveguide while gradually "squeezing" of the field by narrowing the part of silicon
waveguide. The modeling is carried out by the beam propagation method (BPM), using 4-th Pade order
approximation. These results agree well with the exact data of direct modeling conducted by the resource
consuming finite difference time domain (FDTD) method. We had got the conditions for maximum efficiency of
wave propagation through the waveguide intersection. Specifically, we the first show that the maximum
transmission is achieved if goes to zero the phase difference of the first two modes of a wide channel
waveguide in the intersection (the center of the structure). Due to this effect the passing through the gap in the
photonic wire by intermediate conversion of fields with the joint participation of the pair of modes (of polymer
waveguide) has a higher efficiency than that with only one fundamental mode (99% versus 90%).The second
part of the problem corresponds to the propagation of light in an unbroken silicon wires, and thus the presence
of the polymer waveguide is the disturbing factor. Our goal was to achieve an undistorted transmission of light
in both cross streams, simultaneously, when the number of crossings can be up to several hundred. In this
case, the BPM and FDTD methods are not well suited. Therefore, we chose a kind method of lines (MoL), which
is a specialized numerical and analytical approach used by a number of researchers for the structures with a
high refractive index contrast. We have created original software implementation of this method with the full
participation of the analytical component to provide the required precision. The truth of our results was
confirmed by direct modeling by 3D FDTD.Based on numerical simulations involving different methods (BPM,
MoL and FDTD), we show that the proposed optical element can provide a highly effective crossing (at 98%
and above) at the same time for the direct transmission of light and cross-direction transmission with an
arbitrary number (from 1 to 1024) of the possible intersections (provided that the working wavelength (1.55
microns) is far from the characteristic wavelengths of Bragg reflections observed at periodic perturbation
location).
Полное название организации, где реализуется проектRzhanov Institute of Semiconductor Physics SB RAS