Studying focal ratio degradation of optical fibers for Subaru Prime Focus Spectrograph

Abstract

Focal Ration Degradation (FRD) is a change in light angular distribution caused by fiber optics. FRD is important to fiber-fed, spectroscopic astronomical systems because it can cause loss of signal, degradation in spectral resolution, or increased complexity in spectrograph design. Laboratório Nacional de Astrofísica (LNA) has developed a system that can accurately and precisely measures FRD, using an absolute method that can also measure fiber throughput. This paper describes the metrology system and shows measurements of Polymicro fiber FBP129168190, FBP127165190 and Fujikura fiber 128170190. Although the FRD of the two fibers are low and similar to one another, it is very important to know the exact characteristics of these fibers since both will be used in the construction of FOCCoS (Fiber Optical Cable and Connectors System) for PFS (Prime Focus Spectrograph) to be installed at the Subaru telescope.

6 Pages, 10 Figures

Cited by in corpus (5)

• Prime Focus Spectrograph for the Subaru telescope: massively multiplexed optical and near-infrared fiber spectrograph
• A modified method for determining the FRD and length properties of optical fibres in astronomy
• Focal ratio degradation for fiber positioner operation in astronomical spectrographs
• DEEM, a versatile platform of FRD measurement for highly multiplexed fibre systems in astronomy
• Optical design of a multi-object fiber-fed spectrograph system for Southern Spectroscopic Survey Telescope