Abstract: Disclosed is a quantum key distribution system using an RFI (reference frame independent) QKD (quantum key distribution) protocol, which includes a first signal processing circuit that generates transmission basis information and transmission bit information, a quantum channel transmitter that generates a single photon or coherent light, and modulates the single photon or the coherent light based on the transmission basis information and the transmission bit information to generate a quantum signal, a quantum channel receiver that receives the quantum signal through a quantum channel and detects reception bit information from the quantum signal based on reception basis information, and a second signal processing circuit that generates the reception basis information, transmits the reception basis information to the first signal processing circuit through a public channel, and receives the transmission basis information from the first signal processing circuit through the public channel.

Abstract: Disclosed is a quantum key distribution system using an RFI (reference frame independent) QKD (quantum key distribution) protocol, which includes a first signal processing circuit that generates transmission basis information and transmission bit information, a quantum channel transmitter that generates a single photon or coherent light, and modulates the single photon or the coherent light based on the transmission basis information and the transmission bit information to generate a quantum signal, a quantum channel receiver that receives the quantum signal through a quantum channel and detects reception bit information from the quantum signal based on reception basis information, and a second signal processing circuit that generates the reception basis information, transmits the reception basis information to the first signal processing circuit through a public channel, and receives the transmission basis information from the first signal processing circuit through the public channel.

Abstract: Provided herein is a semiconductor light emitting device capable of increasing the light extraction efficiency and a fabricating method thereof, the device including a buffer layer formed on a substrate; an n-type semiconductor layer formed on the buffer; an active layer formed on a partial area of the n-type semiconductor layer such that the n-type semiconductor layer is exposed; a p-type semiconductor layer formed on the active layer; a transparent conductive layer formed on the p-type semiconductor layer; a first mesa surface formed along a side wall of the active layer from a side wall of the transparent conductive layer; a passivation layer formed along the first mesa surface; and a metal reflectance film formed along the passivation layer such that it re-reflects escaping light, thereby re-reflecting escaping light to increase the light extraction efficiency.