Spot size estimation of flat-top beams in space-based gravitational wave detectors

authored by: Zhen-Xiang Hao, Tim Haase, Hong-Bo Jin, Ya-Zheng Tao, Gudrun Wanner, Ruo-Xi Wu, Yue-Liang Wu
Abstract: Motivated by the necessity of a high-quality stray light control in the detection of the gravitational waves in space, the spot size of a flat top beam generated by the clipping of the Gaussian beam (GB) is studied. By adopting the mode expansion method (MEM) approach to simulating the beam, a slight variant of the definition of the mean square deviation (MSD) spot size for the MEM beam is proposed. This enables us to quickly estimate the spot size for arbitrary propagation distances. Given that the degree of clipping is dependent on the power ratio within the surface of an optical element, the power ratio within the MSD spot range is used as a measure of spot size. The definition is then validated in the cases of simple astigmatic Gaussian beam and nearly-Gaussian beam profiles. As a representative example, the MSD spot size for a top-hat beam in a science interferometer in the detection of gravitational waves in space is then simulated. As in traditional MSD spot size analysis, the spot size is divergent when diffraction is taken into account. A careful error analysis is carried out on the divergence and in the present context, it is argued that this error will have little effect on our estimation. Using the results of our study allows an optimal design of optical systems with top-hat or other types of non-Gaussian beams. Furthermore, it allows testing the interferometry of space-based gravitational wave detectors for beam clipping in optical simulations. This work will serve as a useful guide in the future system design of the optical bench and the sizes of the optical components.
Organisation(s): QuantumFrontiers
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
CRC 1464: Relativistic and Quantum-Based Geodesy (TerraQ)
External Organisation(s): Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
Chinese Academy of Sciences (CAS)
Type: Article
Journal: International Journal of Modern Physics D
Volume: 32
ISSN: 0218-2718
Publication date: 23.12.2022
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Astronomy and Astrophysics, Mathematical Physics, Space and Planetary Science
Electronic version(s): https://doi.org/10.48550/arXiv.2210.00509 (Access: Open)
https://doi.org/10.1142/S0218271822501346 (Access: Closed)

BibTeX

@article{b76a47c4f7154b30bcf9337afa9225f8,
title = "Spot size estimation of flat-top beams in space-based gravitational wave detectors",
abstract = "Motivated by the necessity of a high-quality stray light control in the detection of the gravitational waves in space, the spot size of a flat top beam generated by the clipping of the Gaussian beam (GB) is studied. By adopting the mode expansion method (MEM) approach to simulating the beam, a slight variant of the definition of the mean square deviation (MSD) spot size for the MEM beam is proposed. This enables us to quickly estimate the spot size for arbitrary propagation distances. Given that the degree of clipping is dependent on the power ratio within the surface of an optical element, the power ratio within the MSD spot range is used as a measure of spot size. The definition is then validated in the cases of simple astigmatic Gaussian beam and nearly-Gaussian beam profiles. As a representative example, the MSD spot size for a top-hat beam in a science interferometer in the detection of gravitational waves in space is then simulated. As in traditional MSD spot size analysis, the spot size is divergent when diffraction is taken into account. A careful error analysis is carried out on the divergence and in the present context, it is argued that this error will have little effect on our estimation. Using the results of our study allows an optimal design of optical systems with top-hat or other types of non-Gaussian beams. Furthermore, it allows testing the interferometry of space-based gravitational wave detectors for beam clipping in optical simulations. This work will serve as a useful guide in the future system design of the optical bench and the sizes of the optical components.",
keywords = "Laser optical systems, space mission, gravitational wave",
author = "Zhen-Xiang Hao and Tim Haase and Hong-Bo Jin and Ya-Zheng Tao and Gudrun Wanner and Ruo-Xi Wu and Yue-Liang Wu",
year = "2022",
month = dec,
day = "23",
doi = "10.48550/arXiv.2210.00509",
language = "English",
volume = "32",
journal = "International Journal of Modern Physics D",
issn = "0218-2718",
publisher = "World Scientific Publishing Co. Pte Ltd",
number = "1",
}