Abstract

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 ${\lt}.01$) can be attained with good control of spill, even when the exit surface is less than three source diameters from the embedded source.

© 2020 Optical Society of America

Full Article  |  PDF Article
More Like This
Compact freeform illumination system design for pattern generation with extended light sources

Christoph Bösel and Herbert Gross
Appl. Opt. 58(10) 2713-2724 (2019)

Designing double freeform surfaces for large ray bending irradiance tailoring of extended LED sources

Yuyin Li, Zexin Feng, Dewen Cheng, and Yongtian Wang
Opt. Express 29(9) 13469-13485 (2021)

Freeform optics design for extended sources in paraxial approximation exploiting the expectation maximization algorithm

Annika Völl, Michael Berens, Rolf Wester, Paul Buske, Jochen Stollenwerk, and Peter Loosen
Opt. Express 28(24) 37004-37014 (2020)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (7)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (5)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription