This figure is a schematic view of interferometer basement under the Keck domes and building.  The light from the two Kecks is transported via a series of coude mirrors into the K-I and K-II crypts.   From there the light goes into the long delay lines, one for each telescope, to roughly match the pathlengths of the two telescopes.


In this enlarged view the red beam from K-II long delay line and the green beam from the K-I long delay line are folded into the fast delay lines, again one per telescope.  The fast delay lines track at sidereal rate as they search to identically match the paths from the two telescopes.  The beams are compressed from 100 mm in diameter to 25 mm before being folded into the beam combiner lab.  The two separate star images are imaged onto the Keck Angle Tracker (KAT) for tip/tilt correction and they are combined onto the fringe tracker camera (FATCAT).  The Interferometer is operated from the adjacent Control Room.


  Copyright 2001 California Association for Research in Astronomy