Choosing a Detector for Optical Power Measurements
应用文章
Photodiode Responsivity
Optical power meters for testing fiberoptic components use semiconductor photodiodes as detectors to generate electrical current proportional to the incident optical power. This photocurrent is then measured, typically with a transimpedance amplifier and analog-to-digital converter, to determine that power. That requires the conversion factor from mA current to mW power, which depends on the wavelength of the light and combines contributions from the properties of the detector as well as any optics used to collect the light. Calibration of the power meter thus involves traceably measuring and recording the wavelength dependent responsivity and including this data with the instrument.