Near field modal noise reduction using annealed optical fiber
Incomplete and unstable mode population has long complicated the application of optical fiber for transferring star and calibration light to high precision spectrographs. The need for improved precision calibrators in support of radial velocity planet surveys has led to the introduction of coherent wavelengths sources using single mode fibers that are then coupled into multi-mode fibers, further exacerbating this problem. We explore mode scrambling in annealed optical fiber with and without agitation, as compared to that obtained using octagonal fiber and using an integrating sphere. We observe improved scrambling with annealed fibers compared to conventional and octagonal fibers.
Physics, Astronomy, and Materials Science
annealed fiber, modal noise, near infrared, radial velocity, spectroscopy
Osterman, Steven N., Gabriel G. Ycas, Chelsea Donaldson, Scott A. Diddams, Suvrath Mahadevan, Lawrence W. Ramsey, and Peter P. Plavchan. "Near field modal noise reduction using annealed optical fiber." In Ground-based and Airborne Instrumentation for Astronomy V, vol. 9147, p. 91475C. International Society for Optics and Photonics, 2014.
Proceedings of SPIE - The International Society for Optical Engineering