English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Higher order Laguerre-Gauss (LG) beams have been proposed for use in futuregravitational wave detectors, such as upgrades to the Advanced LIGO detectorsand the Einstein Telescope, for their potential to reduce the effects of thethermal noise of the test masses. This paper details the theoretical analysisand simulation work carried out to investigate the behaviour of LG beams inrealistic optical setups, in particular the coupling between different LG modesin a linear cavity. We present a new analytical approximation to compute thecoupling between modes, using Zernike polynomials to describe mirror surfacedistortions. We apply this method in a study of the behaviour of the LG33 modewithin realistic arm cavities, using measured mirror surface maps from theAdvanced LIGO project. We show mode distortions that can be expected to arisedue to the degeneracy of higher order spatial modes within such cavities andrelate this to the theoretical analysis. Finally we identify the mirrordistortions which cause significant coupling from the LG33 mode into otherorder 9 modes and derive requirements for the mirror surfaces.

Higher order Laguerre-Gauss mode degeneracy in realistic, high finesse cavities