End effects in optical fibres

Abstract

The performance of highly-multiplexed spectrographs is limited by focal degradation (FRD) in the optical fibres. It has already been shown that this is caused mainly by processes concentrated around the mounting points at the ends of the fibres. We use the thickness of rings produced in the farfield when a fibre is illuminated by a collimated beam, to estimate the size of the region where the FRD is generated. This requires the development of a new model, using features of existing ray-tracing and wave-based models, which fits existing data very well. The results suggest that the amount of FRD is primarily determined by the length of fibre bonded into the supporting ferrule. We point out the implications for the production of future fibre systems.

Accepted for publication by MNRAS

References in corpus (3)

• The BigBOSS Experiment
• Impact of surface-polish on the angular and wavelength dependence of fiber focal ratio degradation
• Simulation of complex phenomena in optical fibres

Cited by in corpus (6)

• The DESI Experiment Part II: Instrument Design
• 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
• Fiber positioning in microlens-fiber coupled integral field unit
• Optimization of telescope focal ratios for MLA-fiber coupled Integral Field Units