Cascade waveguide-based double-step structure end face coupler

Abstract

The invention discloses a cascaded waveguide-based end face coupler with a double-step structure. The cascaded waveguide-based end face coupler is formed by cascading a first waveguide and a second waveguide, introducing a ridge waveguide on the first waveguide; the end surfaces of the ridge waveguide and the first waveguide are flush to form an initial input end surface of the coupler, and the initial input end surface is completely matched with the size of the AWG output waveguide; the length of the ridge waveguide is equal to that of the first waveguide, the width of the ridge waveguide is gradually reduced from the initial input end face to the output end face, and the projection of the ridge waveguide on the first waveguide is an isosceles trapezoid; the second waveguide adopts a regular conical structure which is three-dimensionally reduced from the waveguide input end face to the waveguide output end face, the size of the second waveguide input end face is matched with that of the first waveguide output end face, the size of the output end face of the second waveguide is completely matched with that of the ridge waveguide of the photoelectric detector, and the first waveguide, the second waveguide and the ridge waveguide are of a double-step structure. The coupler is small in size, low in loss, high in error tolerance and capable of achieving efficient coupling of waveguides of different sizes.

Description

technical field [0001] The invention relates to the technical field of communication optical devices, in particular to an end-face coupler with a double-step structure based on cascaded waveguides. Background technique [0002] With the rapid development of the field of high-speed optical communication, the integration of optical devices is getting higher and higher, and the coupling requirements for different optical devices are also getting higher and higher. Due to the large dimensional difference between the devices, connecting them directly will cause a large mode field mismatch problem, resulting in a large optical transmission loss. To solve this problem, we usually use couplers to improve device coupling efficiency. [0003] For the coupler, we not only require it to have high coupling efficiency, low loss, small volume, and large error tolerance, but also should be insensitive to wavelength and polarization state to ensure that it can be used in a wider band. and ...

AI Technical Summary

Problems solved by technology

However, the size of the traditional single inverted cone end face coupler is long, and because the cross-sectional area of ​​the inverted cone structure is small, the error tolerance is small and the processing is difficult

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