Speaker
Description
Single-photon sources (SPSs) based on spontaneous parametric down-conversion (SPDC) are inherently probabilistic, producing a usable photon with a probability of about $0.25$. This is too low for scalable quantum technologies, especially when optical losses and detector inefficiencies are included. Spatial multiplexing offers a solution by combining many identical heralded sources in parallel. However, the number of possible binary-tree multiplexer structures grows factorially $(N!)$ with system size $N$, making full optimisation computationally demanding.
This work analyses spatially multiplexed SPSs constructed from asymmetric photon routers and develops a combined full and stepwise optimisation method to identify multiplexer structures that maximise the single photon output probability under realistic loss parameters. The model includes thermal photon pair statistics, photon number resolving detector response, router transmission coefficients $(V_r,V_t)$, and propagation losses $V_b$ . Several output-extended incomplete binary-tree multiplexers (OIBTMs) are evaluated, and the optimal number of multiplexed units N, the optimal mean-photon number $λ$ , and the optimal multiplexer topology are determined for each parameter set.
The results show that optimised OIBTMs outperform conventional symmetric and asymmetric multiplexers, achieving single-photon probabilities above $90$% for realistic device efficiencies. This work provides a practical framework for designing high-performance multiplexed single-photon sources for photonic quantum technologies.
| Apply for student award at which level: | MSc |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |