how to calculate length of a photonic waveguide spiral in klayout - SERP Analysis

https://www.klayout.de/forum/discussion/540/how-to-measure-cumulative-length-of-selected-lines

https://www.klayout.de/forum/discussion/965/waveguide-resizing-without-pcell

https://github.com/gdsfactory/gdsfactory/discussions/3491

https://academy.lucedaphotonics.com/pdks_sources/si_fab/si_fab/ipkiss/si_fab/components/spiral/doc/

https://www.klayout.org/svn-public/packages-migrated/sebastian-goeldi/KLayoutPhotonicPCells-core/tags/v1.1.0/docs/KLayoutPhotonicPCells.pdf

https://www.spiedigitallibrary.org/journals/journal-of-micro-nanopatterning-materials-and-metrology/volume-24/issue-01/013202/Optimal-shape-approximation-and-writing-strategy-for-integrated-photonic-waveguides/10.1117/1.JMM.24.1.013202.full

https://gdsfactory.github.io/gdsfactory/components.html

https://www.researchgate.net/figure/a-Mask-layout-of-spiral-delay-lines-with-522-cm-total-length-and-850-m-minimum-bend_fig3_326473432

https://opg.optica.org/oe/abstract.cfm?uri=oe-21-7-8953

https://academy.lucedaphotonics.com/designs/opa_shuksan/opa_shuksan