Technical Advantages
- Receive weak light:
The device's objective lens captures weak natural light (such as starlight, moonlight) or reflected light in the environment, the intensity of which is usually below the visible threshold of the human eye (about 0.1 lux or less).
- Photoelectric conversion:
After the light enters the micro-light tube (core component), it shines on the photocathode. The cathode material (such as cesium antimonide) absorbs the photon energy and releases photoelectrons (photoelectric effect).
- Electron multiplication:
The released photoelectrons are accelerated by the high voltage electric field (several thousand volts) inside the micro-phototube and hit the microchannel plate (MCP) - a thin sheet composed of millions of microscopic conductive channels. The electrons collide with the tube wall multiple times in the channel, triggering secondary electron emission, which exponentially multiplies the number of electrons (up to tens of thousands to hundreds of thousands of times).
- Electro-optical conversion:
The multiplied electron beam hits the fluorescent screen, and the fluorescent substance (such as cadmium zinc sulfide) absorbs the electron energy and emits visible light, forming a bright image corresponding to the original scene, which is finally observed by the human eye through the eyepiece.
