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This paper presents a methodology for illumination optics tolerancing. Specifically, we investigate tolerancing deformation of a single freeform surface under a point source illumination. Through investigation, we recognized and report here three surface-deformation characteristics that build tolerancing intuitions. First, we show that positive and negative irradiance changes occur together as a consequence of flux conservation. Then, we demonstrate a linear relationship between the steepness of the surface perturbation and the magnitude of the irradiance change. Lastly, we show that the Laplacian magic mirror concept (M. V. Berry [Eur. J. Phys.27,109(2006)10.1088/0143-0807/27/1/012]) can be expanded to surface deformation tolerancing. Utilizing these surface deformation characteristics, we propose a fast and predictable tolerancing method for a sequential illumination optic.
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Estimating the irradiance of a perturbed surface under an extended source
This paper presents a method for evaluating the irradiance of a single freeform surface deviation under extended source illumination. The method takes advantage of a well-known concept, the pinhole image. First, the irradiance of the perturbed freeform surface under point source illumination is computed. Second, a pinhole image of the extended source is obtained by placing a small aperture (pinhole) on the freeform surface. Then, the extended source irradiance pattern change can be quickly calculated by convolving the pinhole image with the perturbed point source irradiance change. The method was experimentally verified, demonstrating the efficacy of the underlying concept. The proposed method alleviates the computational demands during extended source tolerancing, expediting the process.
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- PAR ID:
- 10508817
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Express
- Volume:
- 32
- Issue:
- 12
- ISSN:
- 1094-4087; OPEXFF
- Format(s):
- Medium: X Size: Article No. 20959
- Size(s):
- Article No. 20959
- Sponsoring Org:
- National Science Foundation
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