Figure 4

Schematic of the QRNG setup. A continuous wave laser (CW) is carved to form a train of pulses according to the protocol selected by the user. A combination of an attenuator (att.) and a 99:1 beamsplitter bring the power to single photon level where the 99% output is monitored constantly with a power meter (PM) to certify the overlap condition. The single photons are then sent to a detector (SNSPD) for measurement. The polarization controller (PC) adjusts the polarization to maximize efficiency. The detection events are registered with a time-to-digital converter (TDC). State generation and measurement are governed and synchronized with the field programmable gate array (FPGA)