LED beam shaping lens based on the near-field illumination.

This paper presents a novel method in near-field beam shaping based on the precise optical modeling of a gallium nitride light-emitting diode (GaN LED). A Monte Carlo ray tracing simulation has been utilized to calculate the spatial photon distribution near the LED's top. By analyzing the ray data in near-field, the miniaturized lens profile is created and machined with aspherical surfaces and total internal reflection (TIR) Fresnel facets. The prototype lens reduce the viewing angle of the LED from 150 degrees to 17.5 degrees at full width half maximum (FWHM) while increasing the peak luminous intensity 10 times. The array of proposed lens with CSP LEDs exhibits feasibility of ultra thin uniform illumination in near-field.