Fotokatodas

Fotokatodas is a term often used in the context of vacuum tubes and photodetectors, referring to the cathode element that is sensitive to light. When photons strike the surface of the fotokatodas, they can cause the emission of electrons through the photoelectric effect. This phenomenon is fundamental to the operation of many electronic devices.

The material used for a fotokatodas is crucial for its performance. Typically, alkali metals like cesium, antimony, or combinations of these with other elements are employed due to their low work functions, meaning they require less energy to release electrons. The sensitivity of a fotokatodas to different wavelengths of light depends on its composition and any coatings applied.

Fotokatodas are integral components in devices such as photomultiplier tubes, phototubes, and image intensifiers. In these applications, the emitted electrons are amplified and processed to detect light levels, measure light intensity, or convert optical signals into electrical signals. The efficiency of the photoelectric conversion at the fotokatodas directly impacts the overall sensitivity and performance of the device.