A silicon-based optical waveguide integrated photodetector for visible and near-infrared bands

Abstract

The invention discloses a visible light and near-infrared band silicon-based optical waveguide-integrated photoelectric detector. A passive input optical waveguide comprises a first silicon substrate, a passive region waveguide lower cladding layer, a core-layer strip waveguide and a passive region waveguide upper cladding layer, wherein the passive region waveguide lower cladding layer, the core-layer strip waveguide and the passive region waveguide upper cladding layer are laminated from top to bottom; the passive region waveguide upper cladding layer coats the core-layer strip waveguide; an active light absorption region comprises a second silicon substrate, a diffraction laminate structure, a metal reflective mirror and metal electrodes; the diffraction laminate structure, the metal reflective mirror and the metal electrodes are laminated from top to bottom; the diffraction laminate structure covers the second silicon substrate; the metal reflective mirror covers the diffraction laminate structure; the metal electrodes cover the second silicon substrate at two sides of the diffraction laminate structure; and the diffraction laminate structure comprises an active region waveguide lower cladding layer, diffraction gratings and an active region waveguide upper cladding layer. The visible light and near-infrared band silicon-based optical waveguide-integrated photoelectric detector can be conveniently integrated with other integrated optical waveguide devices only through a simple optical waveguide structure, and implementation of an integrated, miniaturized, portable and low-cost photoelectric detection receiving system is facilitated.

Description

technical field [0001] The invention relates to a silicon-based photodetector, in particular to a silicon-based optical waveguide integrated photodetector for visible light and near-infrared bands. Background technique [0002] In the fields of drug development, environmental monitoring, food safety testing and other fields, reliable testing methods are indispensable, and sensing technology is its core technology. Using advanced sensing technology, qualitative or quantitative analysis can be performed on the composition / concentration of substances. Optical sensing is an important branch of sensing technology, which usually includes two parts: sensing unit and photodetector. [0003] For an integrated optical waveguide sensing system, a photodetector is an essential component for converting optical signals into electrical signals for subsequent signal processing. For visible and near-infrared bands, silicon-based photodetectors are a good choice, and their structure include...

AI Technical Summary

Problems solved by technology

However, this monolithic integration is not easy. The difficulty lies in: for the passive input optical waveguide of the sensing unit and photodetector, the optical waveguide buffer layer must be thick enough to prevent silicon substrate leakage loss; In the light absorption region of the photodetector, the optical waveguide buffer layer should be as small as possible, so that the light field can quickly leak to the substrate and be absorbed by the silicon substrate to form a photocurrent

Therefore, if the traditional optical waveguide technology is used, the difference in the thickness of the buffer layer makes the structure and process of the optical waveguide integrated photodetector more complex, and it is difficult to achieve integration and low cost.

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