Whale, Mark and Murphy, J.Anthony and Murk, Axel and Renker, Matthias and Frisk, Urban and Janson, Olle (2013) A Compensating Anastigmatic Submillimeter Array Imaging System for STEAMR. Terahertz Science and Technology, IEEE Transactions, 3 (1). pp. 110-119. ISSN 2156-342X

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Abstract

In this paper, we present a novel technique for the removal of astigmatism in submillimeter-wave optical systems through employment of a specific combination of so-called astigmatic off-axis reflectors. This technique treats an orthogonally astigmatic beam using skew Gaussian beam analysis, from which an anastigmatic imaging network is derived. The resultant beam is considered truly stigmatic, with all Gaussian beam parameters in the orthogonal directions being matched. This is thus considered an improvement over previous techniques wherein a beam corrected for astigmatism has only the orthogonal beam amplitude radii matched, with phase shift and phase radius of curvature not considered. This technique is computationally efficient, negating the requirement for computationally intensive numerical analysis of shaped reflector surfaces. The required optical surfaces are also relatively simple to implement compared to such numerically optimized shaped surfaces. This technique is implemented in this work as part of the complete optics train for the STEAMR antenna. The STEAMR instrument is envisaged as a mutli-beam limb sounding instrument operating at submillimeter wavelengths. The antenna optics arrangement for this instrument uses multiple off-axis reflectors to control the incident radiation and couple them to their corresponding receiver feeds. An anastigmatic imaging network is successfully implemented into an optical model of this antenna, and the resultant design ensures optimal imaging of the beams to the corresponding feed horns. This example also addresses the challenges of imaging in multi-beam antenna systems.

Item Type:	Article
Additional Information:	Cite as: M. Whale, A. Murphy, A. Murk, M. Renker, U. Frisk and O. Janson, "A Compensating Anastigmatic Submillimeter Array Imaging System for STEAMR," in IEEE Transactions on Terahertz Science and Technology, vol. 3, no. 1, pp. 110-119, Jan. 2013, doi: 10.1109/TTHZ.2012.2228895.
Keywords:	ABCD matrices; anastigmatic; astigmatic; Gaussian beams; multi-beam; quasi-optical; STEAMR;
Academic Unit:	Faculty of Science and Engineering > Experimental Physics
Item ID:	14043
Identification Number:	https://doi.org/10.1109/TTHZ.2012.2228895
Depositing User:	Dr. Anthony Murphy
Date Deposited:	19 Feb 2021 15:13
Journal or Publication Title:	Terahertz Science and Technology, IEEE Transactions
Publisher:	IEEE
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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