Photodiodes are devices made of semiconductor materials that convert light into an electrical current. Since the current is generated by the electron-hole pairs in the p-n junction of the semiconductor, the responsivity of this device depends on the bandgap of the material and varies greatly with wavelength.

The highly wavelength-dependent spectral response of photodiodes can be both an advantage and a drawback. The spectral response of these detectors act as a natural filter to block out noise from other sources, but it also means that different detectors must be used to measure different light sources. 

Compared to thermopiles, photodiodes are faster, are less affected by temperature fluctuations and have lower noise levels. On the other hand, their high sensitivity makes them susceptible to noise coming from ambient light. 

Our products in the PH series use the photodiode technology.

Browse Photodiode Power Detectors here.