What are the methods of photoelectric signal change and detection?

The photoelectric detection system consists of an optical transmitter, an optical channel and an optical receiver. Optical transmitter: divided into active and passive. Active: light source (or modulator) passive: photothermal radiation emitted by the measured object without its own light source. Optical channels: atmosphere, space, underwater and optical fiber, etc. Optical receiver: collects incident optical signals and processes them to recover optical carrier information. The characteristic of photoelectric detection technology is high precision. The highest among various detection technologies. For example, the length detection accuracy of laser interferometer method reaches 0.05 um/m; Angle measurement by grating moire fringe method can reach 0.04 seconds; The resolution of measuring the distance between the earth and the moon by laser ranging method can reach1m. High speed. Photoelectric detection takes light as the medium, and optical methods are the fastest to obtain and transmit information. Long distance, long distance. A medium in which light can propagate over a long distance, suitable for remote control and telemetry, such as weapon guidance, photoelectric tracking, television telemetry, etc. Non-contact detection. Lighting can be considered as non-measuring force and friction, which can realize dynamic measurement and has the highest efficiency. Longevity Light waves can be used forever. Strong information processing and computing skills. Complex information can be processed in parallel. At the same time, photoelectric method is also convenient for information control and storage, and easy to realize automation and intelligence.