Title: Frequency multiplexed photon pair source and its optical interface with Thulium-based quantum memory

Speaker: Dr. Tanmoy Chakraborty, A-Star Singapore

Abstract: In entanglement distribution-based quantum repeaters, one of the key resources is optically mediated entanglement between distant qubits which can be addressed and controlled individually. Next to optical quantum memories, most quantum repeater architectures also require multiplexed sources of photon pairs and photon detection mechanisms that can distinguish between the multiplexed modes. I will present the development of a novel alignment-free, frequency multiplexed photon pair source that is based on fiber-pigtailed, cavity-enhanced spontaneous parametric down-conversion (SPDC) in a nonlinear crystal and is easy to integrate with a practical quantum repeater. I will also present the design and implementation of a novel demultiplexing setup for frequency-resolved detection of the photons. I will show the characterization of multiple pairs of spectrally-resolved modes, as required for a quantum repeater and demonstrate the optical interface of our single photon source with Thulium-based quantum memory. Moreover, I will present the implementation of an optical interface between an nitrogen vacancy (NV) center in diamond and Thulium ion compatible photonic time-bin.