FRD and scrambling properties of recent non-circular fibres

摘要

Optical fibres with octagonal, square and rectangular core shapes have been proposed as alternative to the circular fibresto link the telescopes to spectrographs in order to increase the accuracy of radial velocity measurements. Theoreticallythey offer better scrambling properties than their circular counterparts. First commercial octagonal fibres provided goodnear field scrambling gains. Unfortunately the far field scrambling did not show important figures.This article shows test results on new fibres from CeramOptec. The measurements show substantial improvements of thefar field scrambling gains. In addition, evaluation of their focal ratio degradation (FRD) shows much better performancesthan previous fibres.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.