First demonstration of electrically driven 1.55 μm single-photon generator

We succeeded in demonstrating single-photon generation from a single InAs quantum dot (QD) at a 1.55 mu m band by current injection. A p-i-n light-emitting diode (LED), which includes a quantum dot layer, was grown on an n-InP substrate and fabricated into a nano scaled mesa structure with electrodes. Electrical pulses of 80 ps width were injected in order to generate excitons in quantum dots. We directly determined the electroluminescence (EL) and radiative lifetime of a single exciton to be 1.59 ns. Hanbury-Brown and Twiss (HBT)-type photon correlation measurements proved the antibunching behavior of exciton recombination in a current-injected quantum dot at a wavelength of 1551.2 nm. These measurements demonstrate that our QD LEDs are sources of triggered single photons in the C-band by current injection.