A photodetector and method of use thereof

Abstract

The application discloses a photodetector and its use method, which relate to the field of optical communication integrated devices. The photodetector includes: an incident waveguide for propagating signal light; a germanium absorption region on the silicon layer, which is used for detecting signal light, and convert the signal light into an electrical signal; the focusing device is used to focus the signal light incident on the waveguide to the silicon layer directly below the germanium absorption region, and the beam converged when the signal light passes through the focusing device and reaches the incident end of the germanium absorption region The width is greater than the width of the germanium absorption region. The usage method includes: the signal light enters the focusing device from the incident waveguide; the focusing device focuses the signal light to the silicon layer directly below the germanium absorption region, and makes the width of the converged light beam when the signal light reaches the incident end of the germanium absorption region larger than that of the germanium absorption region. The width of the absorption region; the germanium absorption region converts the signal light into an electrical signal. This application can not only improve the saturated absorption power of the photodetector, so that no signal distortion occurs during photoelectric conversion, but also improve the responsivity of the device.

Description

technical field [0001] The present application relates to the field of optical communication integrated devices, in particular to a photodetector and a method for using the same. Background technique [0002] At present, silicon-based photonic chips have the advantages of compatibility with standard semiconductor processes, low cost, and high integration, and are gradually being widely adopted by the industry. In the field of optical communication, the device used at the receiving end of the silicon-on-chip integrated system is a waveguide-type silicon-germanium photodetector. [0003] In the related art, the waveguide-type germanium-silicon photodetector adopts a square structure, and light is incident from one end and exits from the corresponding other end, undergoing one-way absorption. However, since the incident light power decreases rapidly from the input end to the output end, in the case of high-power incident, the incident end is prone to saturated absorption, whic...

AI Technical Summary

Problems solved by technology

[0004] Aiming at one of the defects existing in the prior art, the purpose of this application is to provide a photodetector and its use method to solve the problem of saturated absorption easily occurring at the incident end of the waveguide-type silicon-germanium photodetector in the related art to cause photoelectric conversion Problems with signal distortion and reduced responsiveness

Images