Sub-Poissonian photon-states generated by light-emitting-diodes: Coulomb blockade of pump events and Stark-effect blockade of emission events

We review our experimental result on the generation of sub-Poissonian photon fluxes from high-speed light emitting diodes (LEDs) driven by high-impedance constant-current sources and present our new scheme on the basis of Stark-effect blockade of photon emissions. The experiments demonstrate a large noise-suppression of spontaneous photon stream, 3.1 dB below the standard quantum limit level at 80 K and increasing bandwidth (3–16 MHz) for the noise-suppression with increasing pump current (50 μA-5 mA) at room temperature. The latter has been clearly interpreted in terms of the distinctive contribution of collective Coulomb-blockade for pump events and of recombination dynamics to the bandwidth. The basic physics behind the proposed scheme is illustrated, theoretically demonstrating, as a consequence of the coexistence of the Stark-effectand Coulomb-blockade, 4.5 dB-noise-suppression to below the standard quantum limit level in a tailor-made diode driven by a constant voltage source.