title: Diffractive optical element with same diffraction pattern for multicolor light-emitting diodes.
abstract: The wavelength-division multiplexing technique can be utilized in visible light communication to increase the channel capacity when a multicolor mixed white LED is used as light source. In such an application, the illumination area of LEDs should be invariant to the incident wavelength, so as to decrease interference within the adjacent regions. Diffractive optical elements (DOEs) can be used in the optical transmitter system to shape the diffraction patterns into polygons. However, traditional DOEs illuminated by a multicolor mixed white LED would result into diffraction patterns with unequal sizes. In this paper, a hybrid algorithm which combines particle swarm optimization with a genetic algorithm is proposed for multicolor oriented DOEs design. A DOE is designed and fabricated for blue and red LEDs, and experimental results show that diffraction patterns with rather good uniformity as well as quasi-equal size for red and blue LEDs are obtained.
authors.forename: Mengzhu
authors.initials: M
authors.lastname: Chen
authors.forename: Qixia
authors.initials: Q
authors.lastname: Wang
authors.forename: Huarong
authors.initials: H
authors.lastname: Gu
authors.forename: Qiaofeng
authors.initials: Q
authors.lastname: Tan