EpiEL-700 is optimized for rapid electroluminescence (EL) evaluation for LED epiwafers with optically transparent substrates, such as nitride-based LED on sapphire substrate. It has all functions of EpiEL-100 with additional capability for simulating different light extraction approaches. EpiEL-700 can also be used to investigate optical non-uniformity of material structures which leads to different emission intensity on both sides of the epiwafers.