  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.
