Working principle of laser night vision devices There are two types of night vision devices: active and passive. Active night vision systems use near-infrared light as light sources to illuminate targets, such as infrared LEDs, infrared lights, and near-infrared lasers. They use low-illumination cameras or low-light cameras to receive the infrared light reflected by the target, convert it into video signals, and display images simultaneously on the monitor's fluorescent screen. This type of night vision device is called an active infrared night vision device.

There are two types of passive night vision systems,

One type is to use all very weak natural light such as moonlight, starlight, sky glow, night sky light, etc. to amplify and enhance it to achieve visual purposes. This type of night vision device is also called a low-light night vision device.

The other type uses far-infrared sensitive detectors to detect the thermal radiation of the target itself. This type of night vision device is also called a thermal imager. Under natural light illumination passive imaging measurement conditions, due to the influence of various background radiations, the imaging system's ability to image measurements and accurately track long-distance targets is limited.

Using laser active illumination to illuminate distant, small, and dark targets or parts of them can reduce the impact of background radiation and improve the system's accurate tracking and imaging measurement capabilities for long-distance, small, and dark targets.

The working principle of the laser active illumination imaging system is to illuminate the entire target or key characteristic parts of the target by adjusting the focus state (divergence angle) of the emitted laser beam to meet the detection requirements of the receiving system and achieve the purpose of imaging and observing the target. Active laser night vision devices have low cost, easy use, high spatial resolution, can be used day and night (can also be used during the day), have a relatively long detection range, and can identify target camouflage to a certain extent. Therefore, it is very suitable for applications such as public security, armed police and border surveillance. Laser night vision equipment mainly studies active laser illumination infrared night vision equipment to achieve the purpose of detecting targets at night. This night vision device is mainly used for the purpose of military or paramilitary applications.