1. A LED optical source operating with a current of 100 mA generates light at a
wavelength of 1.3 μm, with a total quantum efficiency of 0.02. The diode obeys the
normal diode equation I = I(s)[exp(V/V(T)) – 1], where V(T) = 0.026 V = kT/q is the thermal
voltage. When reversed biased, the diode is found to have a reverse saturation current
of 1 pA.
Calculate the power efficiency of this diode, defined as the optical output power
divided by the electrical input power.