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Silicon photonics interfaced with integrated electronics for 9 GHz measurement of squeezed light


Photonic quantum technology can be enhanced by monolithic fabrication of both the underpinning quantum hardware and the corresponding electronics for classical readout and control. Here, by interfacing complementary metal–oxide–semiconductor (CMOS)-compatible silicon and germanium-on-silicon nanophotonics with silicon-germanium integrated amplification electronics, we curtail total capacitance in a homodyne detector to enhance the speed performance of quantum light measurement. The detector has a 3 dB bandwidth of 1.7 GHz, is shot-noise limited to 9 GHz and has a minaturized required footprint of 0.84 mm2. We show that the detector can measure the continuous spectrum of squeezing from 100 MHz to 9 GHz of a broadband squeezed light source pumped with a continuous-wave laser, and we use the detector to perform state tomography. This provides fast, multipurpose, homodyne detectors for continuous-variable quantum optics, and opens the way to full-stack integration of photonic quantum devices.

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Fig. 1: Device schematic and characterization.
Fig. 2: Measurement of a fibre-coupled squeezing source using the integrated detector.

Data availability

Data are available at the University of Bristol data repository, data.bris, at

Code availability

Code is available at the University of Bristol data repository, data.bris, at


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We are grateful to A. Crimp, M. Loutit and G. Marshall for technical assistance and D. Mahler for helpful discussion. This work was supported by Engineering and Physical Sciences Research Council (EPSRC) programme grant EP/L024020/1, EPSRC UK Quantum Technology Hub in Quantum Enhanced Imaging (QuantIC) (EP/M01326X/1), EPSRC Quantum Technology Capital fund: Quantum Photonic Integrated Circuits (QuPIC) (EP/N015126/1) and the Centre for Nanoscience and Quantum Information (NSQI). J.F. acknowledges support from EPSRC Quantum Engineering Centre for Doctoral Training EP/LO15730/1 and Thales Group. E.J.A. acknowledges support from EPSRC doctoral prize (EP/R513179/1). S.T., V.D. and L.F.B. acknowledge financial support from the European Union by means of the Fond Européen de développement regional (FEDER) through the project OPTique et photonique pour l’Interaction MAtière Lumière (OPTIMAL), the Agence Nationale de la Recherche (ANR) through the projects Hybrid Quantum Light (HyLight) (ANR-17- CE30-0006-01) and Synchronized Pulses in Optical Cavities for Quantum optics and quantum information systems (SPOCQ) (ANR-14-CE32-0019), and the French government through the programme ‘Investments for the Future’ under the Université Côte d’Azur UCA-JEDI project (Quantum@UCA) managed by the ANR (ANR-15-IDEX-01). J.C.F.M. acknowledges support from an EPSRC Quantum Technology Fellowship (EP/M024385/1) and a European Research Council starting grant ERC-2018-STG 803665.

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Authors and Affiliations



J.F.T. and J.F. performed device characterization. J.F.T., J.F. and L.F.B. performed squeezed light measurements. J.F.T., J.F. and G.F. performed data analysis. All authors contributed to the theory, project direction and writing of the manuscript. J.C.F.M. directed the project.

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Correspondence to Jonathan C. F. Matthews.

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Supplementary Figs. 1–10, Discussion and Table 1.

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Tasker, J.F., Frazer, J., Ferranti, G. et al. Silicon photonics interfaced with integrated electronics for 9 GHz measurement of squeezed light. Nat. Photonics 15, 11–15 (2021).

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