Rl The ratio of output current (in Amperes) to input light power (in Watts). It is a constant in the dynamic range, at a given wavelength. (also known as sensitivity).
The detector photocurrent (or voltage) output per unit incident radiant power at a particular wavelength. Expressed in units of amps/watt (or volts/watt).
The ratio of a photodetector's electrical output to its optical input in an optical fiber.