Free-form optics for non-idealized light sources in 3D: a phase-space approach

Völl, Annika; Wester, Rolf; Buske, Paul; Berens, Michael; Stollenwerk, Jochen; Loosen, Peter

doi:10.1117/12.2311995

Cited by 2 publications

(1 citation statement)

References 12 publications

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“…The design algorithm is based on the solution of the so called Monge-Ampère equation and a following flux optimization step [17]. Additionally, we have developed methods which account for finite divergence angles that are based on phase space considerations [18] or utilize the expectation maximization from statistics [19].…”

Section: Freeform Opticsmentioning

confidence: 99%

Application-adapted beam shaping with cutting-edge optical elements in laser materials processing

Völl

Buske

Stollenwerk

et al. 2023

High-Power Laser Materials Processing: Applications, Diagnostics, and Systems XII

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The quality, efficiency and robustness of laser materials processing significantly benefits from an application-adapted beam shaping. For a successful realization of tailored beam shapes that utilizes state-of-the-art optic concepts, research in two different steps is necessary. First, information about the required beam shape (especially in terms of intensity distribution) is needed. During the last years, we have developed and validated a method to solve the so-called inverse heat conduction problem which enables the derivation of an intensity distribution that specifically tailors the induced temperature profile within the processed material. Here, we present the latest enhancement of the algorithm to complex time-dependent scenarios and new applications, e.g. from the field of surface treatment and tape placement. With the knowledge of the target beam shape, in a second step, optical systems must be designed that enable the realization of the achieved, highly complex intensity distributions. We further demonstrate the potential and limits of novel optics such as freeform mirrors, LCoS-SLMs or diffractive neural networks as well as VCSELs for application-adapted beam shaping. We especially present specific design methods that can contribute to a robust, flexible, and practical realization in various applications.

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Section: Freeform Opticsmentioning

confidence: 99%

Application-adapted beam shaping with cutting-edge optical elements in laser materials processing

Völl

Buske

Stollenwerk

et al. 2023

High-Power Laser Materials Processing: Applications, Diagnostics, and Systems XII

Self Cite

View full text Add to dashboard Cite

show abstract

Design of freeforms to uniformly illuminate polygonal targets from extended sources via edge ray mapping

Birch

Brand

2020

Appl. Opt.

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In this article, we consider the design of a compact freeform optical surface that uniformly irradiates an arbitrary convex polygonal region from an extended light source, while controlling spill. This problem has attracted a large body of literature that has primarily covered highly symmetric special cases or cases where the solution is approximated by a zero-étendue design based on a point source. Practical versions of this illumination design problem will likely feature large asymmetric light-emitting diodes, compact lenses, and irregular targets on angled projection surfaces. For these settings, we develop a solution method based on an edge ray mapping that routes maximally off-axis rays from the edges of the source through the edge of the optic to the edges of the target polygon. This determines the sag and normals along the boundary of the freeform surface. A “spill-free” surface is then interpolated from the boundary information and optimized to uniformize the irradiance, while preserving the polygonal boundary. Highly uniform irradiances (relative standard deviation <2024 scite LLC. All rights reserved.

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