Fibers

The fibers may be the single most expensive piece of hardware required for `Ohana. However it is hard to put a price tag to fluoride glass polarization maintaining fibers as current estimates may change with technological breakthroughs. With the current technology, 100 meter fibers have to be spliced together to obtain kilometric lengths and this is an expensive process that may be overcome in the future (Gwenael Mazé, private communication). However, for five pairs of polarization maintaining fibers each one kilometer in length and balanced in dispersion, could cost around M$3. The same five pairs but only 200 meters long would cost k$900. Because `Ohana requires some very long fibers and some other shorter ones, a figure of M$2.5 seems reasonable. To this, has to be added the various fiber couplers that will actually allow the beams to interfere, and this should be on the order of k$100. It should be noted that even though silicate glass fibers (for J and H bands) may be much cheaper on a per meter basis ($\sim$$10/meter), there certainly are hidden costs related to their temperature sensitivity and related active temperature feedback and control.