Progress in LED technology has enabled a variety of new application scenarios also in automotive exterior lighting. A characteristic feature of this field is the dynamic behavior of the lighting scenario. Whereas in the past, mechanical adjustments or several disjoint light sources were necessary, the newest mu LED technology enables a high-resolution source array based on a monolithic block of IC-chip, opto chip, and converter layer. Still, an optical system is required to project the mu LED array onto the road. The optics discussed has to serve multiple functions as it provides imaging quality, bright illumination, as well as stray light control.

Advances in LED technology facilitate a variety of new application scenarios in automotive exterior lighting. Attractive features in this field are related to dynamic lighting scenarios. To replace mechanical adjustments of the past, the newest μLED technology provides a high-resolution source array based on a monolithic block of IC-chip, opto chip, and converter layer. Nevertheless, design and implementation of a corresponding optical system are required to project the μLED array onto the road.

Camera systems are frequently accompanied by LED-illumination. Visual appearance of scenes is compared with reproduction of those scenes based on the CIECAM02 color appearance model. Optimized flash spectra that yield good color reproduction are identified.

Flash light-emitting diodes (LEDs) of modern mobile phones lack red and cyan spectral parts, however, the color gamut of their respective displays has increased in recent years. The influence of this discrepancy on the color reproduction of smart phones is investigated in this paper. Based on the CIECAM02 color appearance model, a metric is introduced to judge color reproduction of mobile phones under flash LED illumination. An evaluation method is established to compare the visual appearance of a scene under various surrounding illuminations with the reproduction of that scene. To facilitate a comparison with measurements, the evaluation method is based on the raw data of two test cameras and a Digital ColorChecker SG. To reduce the color shift between perception and reproduction, optimized flash LED spectra are presented. A single-LED and a double-LED concept with adjustable color temperature are derived from these results. Additionally, the common characteristics of flash LED spectra giving good results is investigated, identifying the spectral parts with the most influence on camera color reproduction and showing the spectral parts not contributing or even resulting in poor color reproduction. Finally the efficiency of optimized flash LED spectra is compared to standard flash LEDs.

Starting with a seminal paper by Forbes [1], orthogonal polynomials have received considerable interest as descriptors of lens shapes for imaging optics. However, there is little information on the application of orthogonal polynomials in the field of non-imaging optics. Here, we consider fundamental cases related to LED primary and secondary optics. To make it most realistic, we avoid many of the simplifications of non-imaging theory and consider the full complexity of LED optics. In this framework, the benefits of orthogonal polynomial surface description for LED optics are evaluated in comparison to a surface description by widely used monomials.

The availability of LEDs as light sources in automotive lighting enables for designing optically efficient and industrial design driven lightguides for various applications, e.g., day-time running lights. To have the most efficient solution the complete system needs to be considered. The main aspects are the LED package design and the light outcoupling out of the LED, the mechanical placement of the LED vs. the lightguide and finally the lightguide geometry including incoupling as well as outcoupling. In this contribution we will especially discuss the influence of LED design on the incoupling efficiency.

Recent years have seen a surge in LED-based automotive headlamps including a variety of lighting functions like low-beam, high-beam, day-time running light as well as fog-light. Many of those lighting functions have been realized by designs that statically provide specific illumination patterns. In contrast, existing adaptive designs rely on either moving shutters or electronically-complex matrix sources.In this paper, alternative options will be explored for an automotive headlamp that combines low-beam and high-beam out of a single LED.The light source comprises two rows of chips arranged on a common carrier resulting in a compact LED. At the same time, electronic complexity is reduced by driving just the two rows independently.Primary optics collects the emission of the two closely-spaced chip rows and simultaneously provides a way to separate respective contributions. The subsequent secondary optics is based on facetted reflector shapes to realize low-beam and high-beam patterns.Efficiency, tolerances, system size, and cross talk will be evaluated for different primary optics based on refraction, reflection as well as TIR.

Good primary optics for LEDs are crucial for applications that work technically and economically. But what is “good”? For various optical design patterns, we look at the complex interplay between optics, manufacturing, tolerancing, lifetime and cost.

The microscopic processes accompanying the catastrophic optical damage process in semiconductor lasers are discussed. For 808 and 650 nm edge-emitting broad-area devices relevant parameters such as surface recombination velocities, bulk and front facet temperatures are determined and discussed. Facet temperatures vs. laser output and temperature profiles across laser stripes reveal a strong correlation to near-field intensity and degradation signatures. Furthermore, the dynamics of the fast catastrophic optical damage process is analyzed by simultaneous high-speed infrared thermal and optical imaging of the emitter stripe. The process is revealed as fast and spatially confined. It is connected with a pronounced impulsive temperature flash detected by a thermocamera.