Fresnel rhombs as achromatic phase shifters for infrared nulling interferometry
Abstract
We propose a new family of achromatic phase shifters for infrared nulling interferometry. These key optical components can be seen as optimized Fresnel rhombs, using the total internal reflection phenomenon, modulated or not. The total internal reflection indeed comes with a phase shift between the polarization components of the incident light. We propose a solution to implement this vectorial phase shift between interferometer arms to provide the destructive interference process needed to disentangle highly contrasted objects from one another. We also show that, modulating the index transition at the total internal reflection interface allows compensating for the intrinsic material dispersion in order to make the subsequent phase shift achromatic over especially broad bands. The modulation can be induced by a thin film of a well-chosen material or a subwavelength grating whose structural parameters are thoroughly optimized. We present results from theoretical simulations together with preliminary fabrication outcomes and measurements for a prototype in Zinc Selenide.
Additional Information
© 2007 Optical Society of America. Received 25 Jun 2007; revised 24 Aug 2007; accepted 25 Aug 2007; published 21 Sep 2007. The authors acknowledge the financial support of ESA.Attached Files
Published - oe-15-20-12850.pdf
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Additional details
- Eprint ID
- 57896
- Resolver ID
- CaltechAUTHORS:20150529-095936261
- European Space Agency (ESA)
- Created
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2015-05-29Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field