FOCCoS for Subaru PFS

Antonio Cesar de Oliveira1, Ligia Souza de Oliveira1, Marcio Vital de Arruda1, Jesulino Bispo dos Santos1, Lucas Souza Marrara1, Vanessa Bawden de Paula Macanhan1, João Batista de Carvalho Oliveira1, Rodrigo de Paiva Vilaça1, Tania Pereira Dominici1, Laerte Sodré Junior2, Claudia Mendes de Oliveira2, Hiroshi Karoji3, Hajime Sugai3, Atsushi Shimono3, Naoyuki Tamura4, Naruhisa Takato4, Akitoshi Ueda4

1 MCT/LNA –Laboratório Nacional de Astrofísica, Itajubá – MG – Brazil
2 IAG/USP – Instituto Astronômico e Geografico/ Universidade de Sao Paulo – SP – Brazil
3 IPMU University of Tokyo, Institute for the Physics and Mathematics of the Universe
4 Subaru Telescope/ National Astronomical Observatory of Japan

The Fiber Optical Cable and Connector System (FOCCoS), provides optical connection between 2400 positioners and a set of spectrographs by an optical fibers cable as part of Subaru PFS instrument. Each positioner retains one fiber entrance attached at a microlens, which is responsible for the F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. The optical fibers cable will be segmented in 3 parts at long of the way, cable A, cable B and cable C, connected by a set of multi-fibers connectors. Cable B will be permanently attached at the Subaru telescope. The first set of multi-fibers connectors will connect the cable A to the cable C from the spectrograph system at the Nasmith platform. The cable A, is an extension of a pseudo-slit device obtained with the linear disposition of the extremities of the optical fibers and fixed by epoxy at a base of composite substrate. The second set of multi-fibers connectors will connect the other extremity of cable A to the cable B, which is part of the positioner’s device structure. The optical fiber under study for this project is the Polymicro FBP120170190, which has shown very encouraging results. The kind of test involves FRD measurements caused by stress induced by rotation and twist of the fiber extremity, similar conditions to those produced by positioners of the PFS instrument. The multi-fibers connector under study is produced by USCONEC Company and may connect 32 optical fibers. The tests involve throughput of light and stability after many connections and disconnections. This paper will review the general design of the FOCCoS subsystem, methods used to fabricate the devices involved and the tests results necessary to evaluate the total efficiency of the set.

Antonio Cesar de Oliveira et al., “FOCCoS for Subaru PFS”, Ground-based and Airborne Instrumentation for Astronomy IV, Ian S. McLean, Suzanne K. Ramsay, Hideki Takami, Editors, Proc. SPIE 8446 (2012).

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