  Existing optical lattice clocks demonstrate a high level of performance, but
they remain complex experimental devices. In order to address a wider range of
applications including those requiring transportable devices, it will be
necessary to simplify the laser systems and reduce the amount of support
hardware. Here we demonstrate two significant steps towards this goal:
demonstration of clock signals from a Sr lattice clock based solely on
semiconductor laser technology, and a method for finding the clock transition
(based on a coincidence in atomic wavelengths) that removes the need for
extensive frequency metrology hardware. Moreover, the unexpected high contrast
in the signal revealed evidence of density dependent collisions in Sr-88 atoms.
