Polarization-independent power divider based on symmetric three-waveguide and sub-wavelength structure

Abstract

The invention discloses a polarization-independent power divider based on a symmetric three-waveguide and a sub-wavelength structure. The polarization-independent power divider based on the symmetricthree-waveguide and the sub-wavelength structure successively consists of a silicon-based substrate (8), a buried oxide layer (9), a silicon waveguide layer (11), and an upper cladding layer (10) in order from bottom to top; the silicon waveguide layer (11) forms a symmetrical three-waveguide directional coupler structure (7) by a right put-through channel (2), a middle put-through channel (3) anda left put-through channel (4); the symmetrical three-waveguide directional coupler structure (7) is provided with an input channel (1) on one side and a right output channel (5) and a left output channel (6) on the other side, and a sub-wavelength grating structure is attached to the surface of each channel; and the directional coupler structure (7) performs 3dB power distribution on different input polarized light. The polarization-independent power divider based on the symmetric three-waveguide and the sub-wavelength structure effectively reduces insertion loss and reflection loss of the power divider in the prior art, improves the power division ratio of the device, and shortens the size of the device.

Description

technical field [0001] The invention relates to a polarization-independent power divider based on a symmetrical three-waveguide and a sub-wavelength structure, belonging to the technical field of integrated optics. Background technique [0002] Photonic integrated circuits (PICs) are considered a good choice for the development of optical computing and high-bandwidth interconnections in next-generation optical networks by providing low-cost optical interconnection solutions and high transmission rates. In recent years, in order to realize photonic integrated circuits, silicon-on-insulator (SOI) materials have attracted people's attention due to their advantages of CMOS-compatible preparation process, high refractive index contrast, low-loss nanowire waveguide, and small device footprint. It has been widely concerned and has been practically applied in many optical fields. The power splitter is an important component of complex optical devices such as mode multiplexers, opti...

AI Technical Summary

Problems solved by technology

Due to the high refractive index contrast between the core and the cladding, the power divider based on the SOI platform has strong birefringence for the transverse electric mode (TE) and transverse magnetic mode (TM) with different polarization characteristics; thus Makes most SOI-based power splitters generally polarization-sensitive, which will negatively impact the performance of the PIC

Traditional polarization-independent power splitters achieve equal coupling lengths of TE and TM modes by introducing thicker silicon waveguide layers, wider waveguide gaps, curved waveguides, or lower waveguide widths; but at the same time it will bring higher The design complexity and power distribution ratio (SR) will also make the insertion loss and reflection loss higher

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