A Position Sensitive Sensor Based on Resonant Cavity Enhancement

Abstract

A position sensitive sensor based on a resonant cavity belongs to the field of semiconductor optoelectronics. From top to bottom, it includes an upper electrode, an anti-reflection film, an upper Bragg reflector, a resonant cavity, a lower Bragg reflector, an N-type substrate layer, and a lower common electrode. Among them, the upper Bragg reflector is composed of low-refractive index material layers and high-refractive index material layers alternately with a thickness of 1 / 4 of the resonance wavelength of the resonator, and the lower Bragg reflector is composed of a single layer with a thickness of 1 / 4 of the resonant wavelength of the resonator. The low refractive index material layer and the high refractive index material layer are alternately composed. The invention realizes a position sensitive sensor with relatively less raw material consumption, stronger anti-interference ability and faster response speed through the resonance enhanced absorption structure formed by the upper Bragg reflector, the resonant cavity and the lower Bragg reflector.

Description

technical field [0001] The invention relates to a resonant cavity enhanced position sensitive sensor (Resonant Cavity Enhanced Position Sensitive Detector, RCEPSD), which belongs to the field of semiconductor optoelectronics. Background technique [0002] A position sensitive sensor (PSD) is an optoelectronic device that is sensitive to the position of an incident light spot on its photosensitive surface. When the position of the incident light spot on the photosensitive surface of the device changes, the electrical signal output by the PSD also changes accordingly. By processing the changed electrical signal, the position of the incident light spot on the photosensitive surface of the PSD device can be determined. In recent years, due to the rapid development of semiconductor lasers, the performance and volume of PSD have been improved, which has promoted the extensive practical research of PSD devices. [0003] PSD is a photodiode with a large photosensitive surface with ...

AI Technical Summary

Problems solved by technology

Although the photoelectric measuring device made of PSD has the characteristics of high position resolution and simple processing circuit, ordinary PSD still has the following disadvantages: 1. The consumption of raw materials is relatively high

The high-resistance semiconductor material 300 under the photosensitive surface acts as a depletion layer to absorb light. In order to improve efficiency, ordinary PSDs usually prepare thicker depletion layers, so ordinary PSD devices consume a lot of raw materials.

2. Poor anti-interference ability

Ordinary PSD adopts PIN structure, and the spectral response range of the I layer that absorbs light, that is, the 300 layer, is wide, so the device not only responds to the signal light source, but also responds to the stray light in the surrounding environment, resulting in its resistance to detecting the position of the light point. Low interference ability

3. The response speed is relatively low

Due to the large thickness of the depletion layer of ordinary PSD, the time for photogenerated carriers to cross the depletion region is long, resulting in a low response speed of the device.

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