Fabrication of a micro elliptical collimator lens for a beam shape form of a Laser Diode

Abstract

LD (Laser Diode) has different divergent angles in horizontal direction and direction, for example the divergent light angle is from 10[deg] to 35[deg] in horizontal direction and from 30[deg] to 40[deg] in vertical direction. To form the beam shape, an aspheric lens or an anamorphic lens has been used. But there are some problems in position alignment of lens or production cost. In this research, we designed and fabricated a lens which forms beam shape by using only one lens that has a different curvature radius in horizontal and vertical directions, in input surface and output surface. As a fabrication method at low cost and high accuracy, we formed UV cure material which is dropped on the substrate to the lens shape mother die by changing the area of the hydrophobic property. And we casted the lens by using the metal mold which is formed by electro plating to the mother die. We evaluated the optical characteristics of the focused LD beam using the fabricated lens. As the result, we confirmed the improvement of the beam shape of the LD by using the fabricated collimator lens.