The 8-cm-long silica-on-silicon photonic chip in the center of the picture was used in the 4 photon QBSM experiment (see figure 3B in the manuscript). Arrays of single-mode fibers were glued to either side of the chip. A red laser is coupled into two fibers (foreground) to illuminate a portion of the on-chip interferometric network. For the boson sampling experiment, the red laser was replaced with single photon sources. There are five thermal phase shifting elements on top of the chip, though they were not used in this work. This image relates to a paper that appeared in the Dec. 20, 2012, issue of Science Express, published by AAAS. The paper, by Justin Spring at University of Oxford in Oxford, UK, and colleagues was titled, "Boson Sampling on a Photonic Chip."