Fiber cable & connector system

The 400 fibers from the Echidna system are fed to the fiber connector system installed on the side of PIR. This system consists of 12 sub-connector units. The main function of this connector system is focal ratio number conversion: The fiber core of an Echidna fiber (F/~2, 100 um diameter) is re-imaged by a pair of plano-convex cylindrical lenses onto the fiber core of the spectrograph-side fiber with a larger diameter (F/~5, 280 um diameter).

The other important function accomodated in the fiber connector system is the back illumination mechanism: Using the insertable pairs of prisms between the Echidna-side and spectrograph-side sub-connectors, the light from an LED illuminates the fiber-connector end of an Echidna fibers and the other end at the prime focus is lit. This enables the Echidna FPI system to measure the current positions of the fibers on the focal plane.

This fiber connector system is a "junction" allowing the PIR to be unplugged from the telescope when FMOS is not in use with the spectrograph-side fiber cables left on the telescope and dome structures.

Fig. 1 - Schmatic view of the roles of the fiber cable & connector system.
Fig. 2 - The fiber connector and fiber slit.
Fig. 3 - Profile of the sub-connector units.
Readers can also refer to the paper as listed below and references therein for more details of this system:

"Design and construction of the fibre system for FMOS": Murray, G., et al. Proc. of SPIE, Vol. 7014, 186

Last updated: Jan 31, 2012