Optical system for a laser-based near-infrared vehicle headlamp

While most of the efforts in the development of vehicle headlamps are focused on the design of high-resolution visible beam distributions, recent research shows the possibilities of using a near-infrared auxiliary headlamp for machine vision. Contrary to previous non-imaging approaches not designed to attenuate parts of the beam, this feature can supplement missing light during low-beam driving. This paper aims to evaluate various emitters and optical concepts for an auxiliary near-infrared headlamp, with particular emphasis on etendue and power density. Firstly, the system requirements for an automotive headlamp consisting of a visible and near-infrared source are discussed. Secondly, we evaluate differnent design approaches to the optical system with focus on the near-infrared subsystem. Consequently, the optomechatronical system is discussed, looking at optics, electronics and mechanics seperately.