Low-power-consumption waveguide optical detector of optical isolation between photosensitive table board and N contact table board

Abstract

The invention relates to a low-power-consumption waveguide optical detector structure of optical isolation between a photosensitive table board and an N contact table board. In the structure, an optical waveguide and a photodiode are integrated on a semi-insulating substrate. The photodiode has an optimized energy band structure, doping distribution and an epitaxial layer thickness. A non-depletion P-type light absorption layer with linear gradient doping distribution, an N-type electron collection layer (non-light absorption layer) with linear gradient doping distribution, and a band gap gradient interval layer with sandwich dipole doping distribution between the absorption layer and the collection layer are mainly included. The photosensitive table board and the N contact table board areoptically isolated by making a groove in the N table board and depositing a metal film electrode so that limitation of the optical waveguide on light is improved. The table board isolated from the Ntable board is manufactured at a tail end of the optical waveguide, and the metal film is deposited to serve as an optical reflector so that an effective absorption length of a device is increased, and a technical scheme for relieving mutual restriction of an optical detector bandwidth and quantum efficiency is provided.

Description

technical field [0001] The invention belongs to the technical fields of optical communication and optoelectronics, and in particular relates to a low-power-consumption waveguide photodetector structure with optical isolation between a photosensitive table and an N-contact table. Background technique [0002] Photodetectors with high quantum efficiency, broadband and high output power are key components in optical communication systems. In general, there is a mutually restrictive relationship between the bandwidth and quantum efficiency of photodetectors. The two main bandwidth limiting factors in photodetectors are carrier transit time and RC time. By reducing the device area or increasing the thickness of the depletion layer, the junction capacitance can be reduced to alleviate the RC time limit. However, increasing the thickness of the depletion layer, especially the thickness of the depleted absorber layer, will increase the carrier transit time. On the other hand, red...

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Problems solved by technology

[0004] In order to solve the problem of mutual restriction between the quantum efficiency and high-speed response of the semiconductor photodetector in the prior art, the present invention improves the structure of the existing waveguide photodetector; designs a monolithic optical waveguide and photodetector Integrated, low-power waveguide photodetector with broadband, high quantum efficiency, and high output power; where the photosensitive mesa is optically isolated from the N-contact mesa, and a metal film is deposited as a light reflector, and the mesa is fabricated at the end of the optical waveguide And deposit a metal thin film as a light reflector, so as to better confine the light on the photosensitive table and improve the quantum efficiency of the device, thereby alleviating the contradiction of the sharp decrease in quantum efficiency when the miniaturized active area increases the bandwidth of the device. A Solution to Simultaneously Achieve High Quantum Efficiency and Broadband

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