Patent ID: 8314440

Claim:
A light emitting diode (LED) chip, comprising: a substrate; a light emitting structure arranged on the substrate, the light emitting structure comprising a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; and an alternately laminated bottom structure disposed on the substrate and comprising dielectric pairs, each of the dielectric pairs comprising a first material layer having a first refractive index and a second material layer having a second refractive index, the first refractive index being greater than the second refractive index, the dielectric pairs comprising: first dielectric pairs each comprising the first material layer and the second material layer, the first material layer and the second material layer each having an optical thickness less than λ/4; a second dielectric pair comprising the first material layer and the second material layer, one of the first material layer and the second material layer having an optical thickness less than λ/4 and the other having an optical thickness greater than λ/4; and third dielectric pairs comprising the first material layer and the second material layer, each of the first material layer and the second material layer having an optical thickness greater than λ/4, wherein λ is a central wavelength of the visible light range, and wherein the first dielectric pairs are located closer to or farther from the substrate than the third dielectric pairs.