Optical field matching filtering range finding device based on M-sequence phase coding

Abstract

An optical field matching filtering range finding device based on M-sequence phase coding comprises a high-speed phase modulating and transmitting end, and a low-speed receiving end. The optical field matching filtering range finding device has advantages of high-speed modulation, high-speed receiving, random distribution for detecting light and reference light strength, no requirement for electronic signal processing, no range finding result effect by target echo waveform interference from multiple distances. A rectangular prism which is driven by a stepping motor is used for adjusting time delay of local reference light, so that a phase coding signal is focused through matched filtering. A relative distance between target points is measured through light path delay of the stepping motor. The optical field matching filtering range finding device acquires distance information through a high-speed phase coding signal, and can obtain a relatively high laser coding signal repetition frequency and a relatively high distance resolution. A low-speed detector which is adopted effectively reduces the requirement of the system to electronic components. The optical delay which is introduced by the stepping motor eliminates an electronic signal processing step.

Description

technical field [0001] The invention relates to phase code distance measurement, more specifically, an optical domain matched filter distance measurement device based on M-sequence phase code. Background technique [0002] In the field of coherent range-Doppler lidar imaging and scanning 3D imaging lidar, various phase encoding waveforms are usually used to obtain the relative distance information of the detection target, and the waveform compression processing based on matched filtering is the key to obtaining relative distance information from the phase encoding waveform The only means of information processing. However, since the range resolution of the phase-encoded waveform is proportional to the phase modulation rate, that is, the higher the modulation rate, the higher the range resolution, but the higher the modulation rate, the higher the bandwidth requirements of the detector under the condition of heterodyne detection The higher it is, the response bandwidth of th...

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Problems solved by technology

However, since the range resolution of the phase-encoded waveform is proportional to the phase modulation rate, that is, the higher the modulation rate, the higher the range resolution, but the higher the modulation rate, the higher the bandwidth requirements of the detector under the condition of heterodyne detection The higher it is, the response bandwidth of the detector is generally required to be not lower than the modulation rate, and the high-bandwidth photodetector is usually expensive due to the production technology, and the requirements for the operating environment are also high, so it becomes a limited phase-encoded coherent One of the main bottlenecks in distance detection

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