Tailoring freeform beam-shaping lenses for edge-emitting lasers

Abstract

The edge-emitting laser diodes (EELs) are widely used in various applications, however, the strongly asymmetric beam profile along the fast and slow axes gives a big challenge to the beam shaping of EEL. Traditional optical devices mainly focus on adjusting the asymmetric divergence angle of the fast and slow axes of the EEL, and it is difficult to achieve flexible and precise control of the luminous distribution of the EEL due to the limited freedom of the conventional beam-shaping element. In this article, we employ freeform lenses to flexibly reshape EEL beams and develop an approach to tackle the obstacles caused by the strongly asymmetric beam profile by generalizing the Monge–Ampère method to tailor freeform beam-shaping lenses. Three typical but challenging beam-shaping tasks show that both the intensity and wavefront of an EEL beam can be reshaped in a desired manner by using a single compact freeform lens without any symmetric restrictions on the architecture of the beam-shaping system.