Abstract
Integrated silicon quantum photonics has emerged as powerful platform to realise quantum technologies such as quantum sensors, quantum information processing and quantum communications. Over the past decade, the complexity of silicon photonic integrated circuits has scaled to hundreds of components including quantum light sources, universal linear optics and integrated detectors. Integration has many benefits over bulk or fibre-based platforms including natural phase stability, high component density and compatibility with active electronic components.In this thesis we report results and progress of experiments that further develop the silicon quantum photonics platform. We begin by considering homodyne detectors and discuss the limits on performance that are caused by interfacing high quality silicon photonic devices with discrete components. We then demonstrate the performance benefits available to homodyne detection if the readout electronics also scale with the photonic chip. This takes the form of a hybrid homodyne detector constructed from a silicon photonic chip, including integrated photodiodes, and a chip scale silicon-germanium amplifier. We demonstrate a detector bandwidth of 1.7 GHz, a full order of magnitude greater than previous results. This performance increase is then leveraged to perform the highest bandwidth homodyne measurement of squeezed vacuum light in any platform.
Next, we consider an experiment where the converse is true. We exploit a quantum effect, nonlinear interference between single photon sources on a silicon photonic chip, to improve the performance of a classical phase modulator. This method increases the phase sensitivity while mitigating the effect of high insertion losses when applied to a switch able photon pair source. We demonstrate 1 GHz modulation of coincidence rates from the source, while reducing power consumption by a factor of four. This result has applications towards reducing the size, weight and power consumption of multiplexed single photon sources. We also discuss a simultaneous application of nonlinear interference to engineer the spectral properties of photon pairs with integrated components.
Finally, we return to integrated homodyne detection and present an experiment in progress to generate and detect a photon-subtracted squeezed state on-chip. We discuss the experimental design, the advantages of the integrated approach and progress at the time of writing.
| Date of Award | 27 Sept 2022 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Jonathan C F Matthews (Supervisor) & John G Rarity (Supervisor) |