Slow propagation of externally injected light pulses in coupled semiconductor laser array

The propagation on an optical pulse injected into an array of semiconductor lasers is studied. Below lasing threshold, the array supports distortion-free, low-loss, slow-light propagation. Approximated expressions for the group velocity and the attenuation coefficient are derived analytically and verified numerically. The tradeoffs between the amplitude attenuation and the group delay are analyzed and an optimal pumping level, providing maximum output power for a desirable delay, is found.