An Optical Waveguide Detector Eliminating Parasitic Capacitance

Abstract

The invention discloses an optical waveguide detector for eliminating parasitic capacitance, which also includes a second waveguide layer, a second insulating layer and an n-electrode, the second waveguide layer is a rectangular body hollowed out in the middle, one side of the second waveguide layer is connected to the first waveguide layer and the insulating layer One contact, the insulating layer 2 is a rectangular body hollowed out in the middle, the bottom of the insulating layer 2 is in contact with the waveguide layer 2, the four walls of the insulating layer 2 are in contact with the inner wall of the waveguide layer 2, the n electrode is placed in the center of the insulating layer 2, and the bottom is in contact with the waveguide layer 2. The waveguide layer two contacts. Beneficial effects of the present invention: after the n-electrode is moved to the rear platform, the n-electrode and the substrate are no longer in contact, and the substrate does not need to be heavily doped to improve conductivity, so that there is no contact between the p-electrode and the substrate The parasitic capacitance is generated again, so that the total capacitance is reduced, thereby improving the response bandwidth of the optical waveguide detector.

Description

technical field [0001] The invention belongs to the field of optoelectronics, in particular to an optical waveguide detector capable of eliminating parasitic capacitance. Background technique [0002] A high-power high-speed photodetector is a detection device based on the interaction between light and matter, and its function is to convert the incident light signal into a high-power high-frequency signal. High-power high-speed optical detector is an indispensable device in optically controlled phased array radar, ultra-high-speed test system and optical fiber LAN communication, and its performance plays a decisive role in the whole system. [0003] Conventional vertical-incidence photodetectors cannot meet both high-speed and high-power requirements. The main reasons are as follows: one is the saturation effect, which limits the photocurrent; the other is the long transit time, which limits the response frequency; the third is that the light absorption of the intrinsic lay...

AI Technical Summary

Problems solved by technology

[0007] Current optical waveguide detectors such as image 3 As shown, the n-electrode is located on the substrate and is in contact with the waveguide layer at the same time. However, due to the small thickness of the waveguide layer, the contact area is very small. In order to increase the contact area and allow a larger current to flow, it is necessary to It is heavily doped to make it have good conductivity; thus, a parasitic capacitance is generated between the p-electrode of the detector and the substrate, and the parasitic capacitance is in parallel with the junction capacitance. Compared with the junction capacitance, the cross-sectional area of ​​the parasitic capacitance and The distance is relatively large, and the capacitive effect cannot be ignored, resulting in a large total capacitance, which limits the response bandwidth of the optical waveguide detector.

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