Multi-chip LED color mixing by diffraction

摘要

A light emitting device in accordance with an embodiment of the present invention includes a diffractive optical element, a first light emitting diode emitting first light having a first range of wavelengths, and a second light emitting diode emitting second light having a second range of wavelengths. The first light is directed onto the diffractive optical element at a first range of angles of incidence, and the second light is directed onto the diffractive optical element at a second range of angles of incidence. The diffractive optical element diffracts at least a portion of the first light and at least a portion of the second light into the same range of angles of diffraction to obtain light having a desired range of wavelengths. A light emitting device in accordance with an embodiment of the present invention can efficiently mix the outputs of two or more light emitting diodes to form a substantially uniform output of, for example, white light.