Design and Simulations of Quantum Light Sources

Jonny Roberts, Robert James Young

Lucas Rickert, Timm Kupko, Sven Rodt +2 more

We present a design study of quantum light sources based on hybrid circular Bragg gratings (CBGs) for emission wavelengths in the telecom O-band. The evaluated CBG designs show photon extraction efficiencies > 95% and Purcell factors close to 30. Using simulations based on the finite element method, and considering the influence of possible fabrication imperfections, we identify optimized high-performance CBG designs which are robust against structural aberrations. In particular, full 3D simulations reveal that the designs show robustness regarding lateral deviations of the emitter position in the device well within reported positioning accuracies of deterministic fabrication technologies. Furthermore, we investigate the coupling of the evaluated hybrid CBG designs to single-mode optical fibers, which is particularly interesting for the development of practical quantum light sources. We obtain coupling efficiencies of up to 77% for off-the-shelf fibers, and again proof robustness against fabrication imperfections. Our results show prospects for the fabrication of close-to-ideal fiber-coupled quantum light sources for long distance quantum communication.

Stephen C. Wein

Many applications of quantum optics demand delicate quantum properties of light carefully tailored to accomplish a specific task. To this end, numerical simulations of quantum light sources are vital for designing, characterizing, and optimizing quantum photonic technology. Here, I show that exploiting information hidden in zero-photon measurement outcomes provides an exponential speedup for time-integrated photon-counting simulations, realizing eight orders of magnitude reduction in the time to compute six-photon detection probabilities while achieving 10 orders of magnitude higher precision compared to the state of the art. This enables simulations of large photonic experiments with an unprecedented level of physical detail. It can accelerate the design of sources to generate photonic resource states for quantum sensing and measurement-based quantum computing while capturing realistic imperfections. It also establishes a general theoretical framework to study dynamic interactions between stationary qubits mediated by measurements of flying qubits, which can be used to model distributed quantum computing and quantum communication.

R. Jason Jones

Matthew Pysher

FU Xiangb

Squeezed light is light source in the experiment of quantum remote sensing. A mode-cleaner, which can suppress frequency fluctuations of the fundamental mode and attenuate the higher order modes, is required for generating squeezed light. In this paper, an optical mode-cleaner with three mirrors ring structure is designed and its consequence on the suppression of higher order modes is characterized. And by means of simulation we optimize the parameters of the mode cleaner. The designed mode-cleaner whose bandwidth is 1.4MHz is able to reduce the suppression of the higher order modes by 12 dB. The mode-cleaner will be constructed and commissioned in the experiment of quantum remote sensing.