Characteristics of electrically driven two-dimensional photonic crystal lasers

We demonstrate room-temperature low-threshold-current lasing action from electrically driven wavelength-scale high-quality photonic crystal lasers having large spontaneous emission factors by solving the theoretical and technical constraints laid upon by the additional requirement of the current injection. The ultrasmall cavity is electrically pulse pumped through a submicron-size semiconductor "wire" at the center of the mode with minimal degradation of the quality factor. In addition, to better utilize the low mobility of the hole, we employ a doping structure that is inverted from the conventional semiconductors. Rich lasing actions and their various characteristics are experimentally measured in the single-cell and three-cell photonic crystal cavities. Several relevant measurements are compared with three-dimensional finite-difference time-domain computations based on the actual fabricated structural parameters. The electrically driven photonic crystal laser, which is a small step toward a "practical" form of the single photon source, represents a meaningful achievement in the field of photonic crystal devices and photonic integrated circuits as well as of great interest to the quantum electrodynamics and quantum information communities.