An amber LED emits monochromatic radiant flux of at a wavelength of

PHYSICS · Subjective · Fermi University Physics · Optics & Photonics · Geometrical optics and imaging · Geometrical optics and imaging

Optics and Photonics, Ch Radiometry and photometry

Problem

An amber LED emits monochromatic radiant flux of

3.0\ \mathrm{W}

at a wavelength of

610\ \mathrm{nm}

, where the standard photopic luminous efficiency function has the value

V(610\ \mathrm{nm}) = 0.5

. Using

K_m = 683\ \mathrm{lm\,W^{-1}}

, find the luminous flux of this LED.