Encoder chip based on vertical coupling grating integration

Abstract

The invention discloses an Encoder chip based on vertical coupling grating integration. The Encoder chip is made of an SOI substrate, then a vertical coupling grating area, an SOI waveguide transmission area, a PD injection area and a metal electrode area are formed on the top layer of the Encoder chip, and moire fringes generated by an indication grating light path are coupled into the structureof the SOI waveguide transmission area from the vertical coupling grating, and the structure of the SOI waveguide transmission area transmits the optical signal to the PD injection area. The optical signal generates a photon-generated carrier in the PD injection area so that the photon-generated carrier is led out by the metal electrode area. The metal electrode area covers the surface of the whole PD injection area so as not to be interfered by stray light, and the scheme can break through the original signal processing resolution from 10 mu m to the size of 300-700nm of the SOI waveguide, which are realized on the premise of not using a subdivider. Compared with a traditional Encoder structure, the signal processing resolution is improved, the integration degree of the structure is alsoimproved, and a good foundation is provided for Encoder series miniaturization.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to the field of high-resolution and high-integration Encoder chips, in particular to an Encoder chip integrated based on vertical coupling gratings. Background technique [0002] Encoder is a kind of sensor (Sensor). Encoders are widely used in various displacement measurements due to their high precision, high resolution and high reliability. There are many types of encoders. According to its structure, there are linear encoder and rotary encoder. Since many linear displacements are generated by the motion of the rotating shaft, rotary encoders are more widely used. [0003] The encoder is divided into electromagnetic type, contact type, photoelectric type and so on according to its detection principle. The photoelectric encoder has the characteristics of non-contact, small size and high resolution. As a precision displacement sensor, it has been widely used in automatic mea...

AI Technical Summary

Problems solved by technology

At the same time, the main purpose of the invention is to diffract the SOI waveguide light upwards into the PD, which is more suitable for the coupling output structure, but not suitable for the Encoder signal processing chip.

Images