3dB directional coupler capable of shortening coupling length and manufacturing method thereof

Abstract

The invention discloses a 3dB directional coupler capable of shortening coupling length and a manufacturing method thereof. The coupler comprises a substrate. The substrate is sequentially covered with a lower cladding layer, a middle cladding layer and an upper cladding layer from bottom to top. A first coupling waveguide is arranged in the middle cladding layer, a second coupling waveguide is arranged in the upper cladding layer, the first coupling waveguide and the second coupling waveguide are each provided with an arc-shaped waveguide and a straight waveguide, and the arc-shaped waveguides are arranged in the middles of the straight waveguides; and a protruding part of the arc-shaped waveguide of the first coupling waveguide and a protruding part of the arc-shaped waveguide of the second coupling waveguide correspond to each other and form a coupling region. According to the invention, the first coupling waveguide and the second coupling waveguide are not in the same plane, and the first coupling waveguide and the second coupling waveguide form the coupling region, and after incident light enters, electric signals in the coupling region are coupled in the first coupling waveguide and the second coupling waveguide which are distributed up and down through an evanescent field, so that the coupling length of a directional coupler can be effectively shortened, the insertion loss is reduced, the process tolerance is expanded, and the coupling efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of communication device processing, and in particular relates to a 3dB directional coupler with shortened coupling length and a manufacturing method. Background technique [0002] With the birth and rapid development of optical fiber communication technology, the demand for optical fiber communication technology is also increasing all over the world. Directional couplers can transmit and distribute optical signals. They are the most widely used optical passive devices in optical fiber communications, and are important optical devices for controlling optical paths in technical engineering. Designing a directional coupler with low insertion loss, high coupling efficiency, and large process tolerance has become a research hotspot in recent years. [0003] In the waveguide coupler, the two coupling waveguides are on the same plane, and the optical signal is coupled back and forth in the waveguide coupling area....

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems of small process tolerance and low coupling efficiency of the existing directional coupler, the present invention proposes a 3dB directional coupler with shortened coupling length and a manufacturing method. poor features

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