The working principle of night vision devices

I. Working Principle

1. Light Collection

The objective lens gathers the weak ambient light (such as moonlight, starlight or atmospheric glow) 

reflected by the target.

2. Photoelectric Conversion

The light is focused on the photocathode (electrode coated with photosensitive material), and the 

photons excite the electrons to escape, forming an electron flow.

 

3. Electron Multiplication

The electron flow passes through the microchannel plate (MCP), and the inner wall of each microchannel

amplifies the number of electrons by thousands to tens of thousands of times through the secondary 

emission effect.

4. Fluore scence Imaging

The multiplied electrons bombard the fluorescent screen, excite the fluorescent material to emit light, 

and form a visible enhanced image (usually green, because humans are sensitive to green).

5. Eyepiece Magnification

The final image is further magnified through the eyepiece for human observation.

II. Main Advantages

1. Passive operation, strong concealment

It does not actively emit infrared or other light sources to avoid exposing its own position, and is suitable

for military, reconnaissance and other scenes.

2. Real-time imaging, no processing required

Images are generated directly through the optical system, without delay, suitable for rapid response in 

dynamic environments.

3. Lightweight and easy to carry

Compact structure, can be integrated into helmets or handheld devices, suitable for single soldiers or 

field use.

4. High sensitivity and resolution

Modern low-light night vision devices can still generate clear images with high detail recognition under 

extremely low illumination (below 0.001 lux).

5. Strong compatibility

Can be used with infrared fill light in a completely dark environment, or combined with other optical 

devices (such as cameras, scopes).

6. Low power consumption and long life

Depends on ambient light, no complex cooling system is required, low power consumption and simple 

maintenance (GaAs cathode is used for the third generation and above, with longer life).

Applicable scenarios

I. Military and law enforcement

1. Night combat and reconnaissance

Night vision goggles are used for night reconnaissance, target positioning and covert operations in 

military operations.

2. Law enforcement and crime tracking

Police use low-light or thermal imaging night vision goggles for night patrols, crime scene evidence 

collection and suspect tracking.

3. Border and customs inspections

In complex environments (such as fog and jungle), night vision goggles help border and customs 

personnel detect smuggling activities or illegal border crossings.

 

II. Public safety and emergency response

1. Search and rescue

During disaster rescue, night vision goggles help search and rescue personnel locate survivors in ruins or

 dark environments and improve rescue efficiency.

2. Firefighting and forest fire prevention

Thermal imaging night vision goggles can penetrate smoke, monitor the dynamics of the fire scene in 

real time, and are used for long-distance monitoring of forest fire prevention (such as laser night vision 

goggles covering a range of 3-5 kilometers).

 

 

III. Industrial and Infrastructure Maintenance

1. Power and Energy Facility Inspection

Thermal imaging technology is used to detect overheating of power lines or leakage of oil and gas 

pipelines to avoid potential accidents.

2. Nighttime Construction and Equipment Maintenance

In mines, oil fields and other places, night vision devices assist workers in equipment inspection or 

operation in low-light environments

IV. Civil and Outdoor Activities

1. Wildlife Observation and Ecological Research

Infrared night vision devices are used to observe animal behavior at night, such as deep-sea 

bioluminescence, turtle egg laying or coral nocturnal activities, to avoid interfering with natural ecology.

2. Hunting and Camping

Hunters use night vision devices to track prey, while outdoor enthusiasts use them for night navigation 

or safety assurance.

3. Fishing and Sailing

Night vision devices help fishermen observe water conditions at night, while crew members use them to

 identify obstacles during night navigation.

 

V. Scientific Research and Special Uses

1. Archaeology and Geological Exploration

Thermal imaging technology can detect buried relics or geological structures under the surface and 

assist in archaeological excavations.

2. Medical treatment and disaster relief

In disaster areas or field medical treatment, night vision devices help medical staff to carry out rescue in 

dark environments.

 

VI. Urban and security monitoring

1. Urban high-point monitoring

Laser night vision devices are used for long-distance monitoring of urban commanding heights (such as 

transportation hubs and large-scale event security), with a coverage range of several kilometers.

2. Commercial and residential security

Fixed night vision cameras are used for nighttime anti-theft monitoring, and some models support 

recording and remote control.

 

Technical classification and adaptation scenarios

Low-light night vision devices: rely on ambient light and are suitable for covert operations (such as 

military reconnaissance).

Thermal imagers: use the infrared radiation of the object itself to form an image, suitable for completely 

dark or smoky environments (such as firefighting and power detection).

Laser night vision devices: long-distance monitoring (such as forest fire prevention and border defense), 

with a coverage range of several kilometers.

The technological progress of night vision goggles has led to the continuous expansion of their application scenarios, extending from the traditional military field to the civilian, scientific research and industrial fields. It is a key tool for enhancing visual capabilities in low-light environments. In the future, with the reduction of costs and technological iterations (such as the popularization of digital night vision goggles), its applications will become more diversified.