= Spectral responsivity
{title2=$R(\lambda)=I/P$}
For a <photodiode> in its linear regime, <spectral responsivity> is the dark-subtracted <electric current> per incident <radiant flux> in a narrow band at <wavelength> $\lambda$, measured in $\mathrm{A\,W^{-1}}$. More generally a <photodetector>'s readout can be electrical voltage or another quantity, with corresponding units. A broad-band readout weights the incoming <optical spectrum> by the detector's <spectral responsivity>; it is not the unweighted total incident <power>. https://www.nist.gov/programs-projects/spectral-responsivity-measurements-and-spatial-spectral-power-responsivity[NIST, Spectral responsivity measurements: wavelength-dependent sensitivity and spatial characterization]{ref}.
Back to article page
