Photomultiplier Tube (PMT) is an ultra-high-sensitivity photodetector device, consisting of an input window, photocathode surface, focusing electrodes, dynodes (multiplier electrodes), and anode. PMT operates based on two physical principles: the photoelectric effect and secondary electron multiplication effect. Its overall operation is divided into three stages: photoelectric conversion, electron multiplication, and signal output, all completed within a high-vacuum tube. It can convert weak optical signals into electrical signals and achieve signal amplification of more than 10,000 times, offering core advantages such as fast response speed, high detection sensitivity, wide dynamic range, and low noise. LBTEK provides photomultiplier detectors using alkali metal or cesium-tellurium (Cs-Te) compound detector elements. These elements are sensitive to ultraviolet, visible, and near-infrared light, with an applicable wavelength range of 185 nm to 920 nm. Different models can precisely match specific detection bands. Note: PMT must be kept away from light whether powered or not.