A Narrowband Filter Based on Phase Modulated Apodization Grating

Abstract

The invention discloses a narrow-band filter based on a phase modulation apodized grating. An input single-mode waveguide is connected to an asymmetric gradient directional coupler via an input tapered waveguide; the asymmetric gradient directional coupler is connected with a curved output waveguide to realize reflective signal output; an upper port at a right end of the asymmetric gradient directional coupler is connected to a left end of an antisymmetric multimode waveguide apodized grating, and a right end of the antisymmetric multimode waveguide apodized grating is connected to the outputsingle-mode waveguide through the output tapered waveguide in order to achieve straight-through end signal output. A grating reflective signal is extracted by the asymmetric gradient directional coupler, the tolerance is large, and the insertion loss is small; the narrow bandwidth is adjustable by adjusting the spacing between the grating teeth and the waveguides; the multimode waveguide only supports two modes, which can avoid crosstalk caused by the coupling of other modes; apodization is realized by adjusting the phase of the grating, and the grating filter with the high sideband suppression ratio is realized, which greatly improves the performance of the grating filter.

Description

Technical field [0001] The invention relates to the field of grating filters, in particular to a narrowband filter based on phase modulation apodization grating. Background technique [0002] Since the 21st century, with the rapid development of integrated circuits, the feature size of transistors has been continuously reduced, and high-speed information has inevitably encountered a series of bottlenecks in terms of speed, bandwidth, and power consumption during the transmission of electrical interconnections. The on-chip optical interconnection based on silicon photonics provides a feasible solution to this technical problem. The exchange of information will be carried out directly on the optical transmission layer. In recent years, integrated optical devices, especially silicon-based integrated optoelectronic devices, have developed rapidly. Silicon-based integrated optoelectronic devices have become a very important research direction in the development of integrated optical d...

AI Technical Summary

Problems solved by technology

Scholars have conducted a series of explorations on narrow-band silicon-based filters. Although filters based on microrings and F-P cavities have narrow bandwidths, they are limited by their own FSR, which limits the range of wavelength division multiplexing.

In addition, a uniform grating is affected by side lobes and has a relatively large crosstalk to adjacent channels. To achieve a narrow bandwidth, the currently reported multimode waveguide grating with an antisymmetric structure needs to increase the waveguide width, so the modes supported by the waveguide will also be greatly increased. will cause some unwanted mode crosstalk

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