Fig. 1: Experimental setup and device spectra.
From: Frequency-bin entanglement-based Quantum Key Distribution
a Simplified sketch of the experimental setup. The direction of the pump(control) laser is indicated with a green(orange) arrow. Optical connections are shown in blue. The frequency-bins of the Alice’s photon (idler) are indicated by a blue and a violet filled circle, while those directed to Bob (signal) by a green and a red filled circle. BS beamsplitter, EDFA Erbium Doped Fiber Amplifier, VOA Variable Optical Attenuator, FPC Fiber Polarization Controller, BPF bandpass filter, DWDM Dense Wavelength Division Multiplexing, PM electro-optic phase modulator, CRC circulator, FBG fiber Bragg grating, SNSPD superconducting nanowire single photon detector, PD photodiode. The layout of the chip shows the two resonators R0 and R1 (black), and the placement of the metallic heaters (yellow). b Spectral response of the device at the idler (left) and signal (right) wavelengths. The encoding of the signal and idler qubits is shown with the same colors used in panel (a).
