Responsivity

n. responsiveness; quality of being quick to respond, reactiveness

Responsivity measures the input–output gain of a detector system. For a system that responds linearly to its input, there is a unique responsivity. For nonlinear systems, the responsivity is the local slope (derivative). In the specific case of a photodetector, responsivity measures the electrical output per optical input. Many common photodetectors respond linearly as a function of the incident power.Responsivity of a photodetector is usually expressed in amperes per watt, or volts per watt, of incident radiant power. Responsivity is a function of the wavelength of the incident radiation and of the sensor properties, such as the bandgap of the material of which the photodetector is made.
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In a photodetector, the ratio of the electrical output to the optical input. (188 ) Note 1: Responsivity is usually expressed in amperes per watt, or volts per watt, of incident radiant power. Note 2: Responsivity is a function of the wavelength of the incident radiation and the bandgap of the material of which the photodetector is made. Deprecated synonym sensitivity.