Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IEEE/LEOS Summer Topical Meetings

An On-Chip Homodyne Detector for Measuring Quantum States

Giacomo Ferranti, Francesco Raffaelli, Dylan H. Mahler, Philip Sibson, Jake Kennard, Alberto Santamato, Gary F. Sinclair, Damien Bonneau, Mark G. Thompson, Jonathan C. F. Matthews

Published Jul 1, 2018• 1 citation
Publisher

Abstract

We present the first silicon-integrated homodyne detector suitable for characterising quantum states of light travelling in a silicon waveguide. We report high-fidelity quantum state tomography of coherent states. The device was also used to generate random numbers at a speed of 1.2 Gbps.
DOI
10.1109/phosst.2018.8456742

Related papers

A homodyne detector integrated onto a photonic chip for measuring quantum states and generating random numbers

Francesco Raffaelli, Giacomo Ferranti, Dylan H. Mahler +7 more

Optical homodyne detection has found use as a characterisation tool in a range of quantum technologies. So far implementations have been limited to bulk optics. Here we present the optical integration of a homodyne detector onto a silicon photonics chip. The resulting device operates at high speed, up 150 MHz, it is compact and it operates with low noise, quantified with 11 dB clearance between shot noise and electronic noise. We perform on-chip quantum tomography of coherent states with the detector and show that it meets the requirements for characterising more general quantum states of light. We also show that the detector is able to produce quantum random numbers at a rate of 1.2 Gbps, by measuring the vacuum state of the electromagnetic field and applying off-line post processing. The produced random numbers pass all the statistical tests provided by the NIST test suite.

arXiv:1612.04676•Quantum Science and Technology•Dec 21, 2017•138 citations

An on-chip homodyne detector for generating random numbers

Dylan H. Mahler, Francesco Raffaelli, Giacomo Ferranti +7 more

Summary form only given. The homodyne detector is a primitive element in many quantum optics experiments. It is primarily a characterization device, used for measuring the quantum state of the electromagnetic field[1]. Quantum integrated photonics[2], in which optical sources, circuits, and detectors are monolithically integrated on a semiconductor chip, provides a compact, scalable, platform in which to implement quantum devices like the homodyne detector. Here, we present a homodyne detector integrated in silicon and use it to generate quantum random numbers.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 1, 2017•0 citations

An On-chip Homodyne Detector for Measuring Quantum States

Dylan H. Mahler, Francesco Raffaelli, Giacomo Ferranti +7 more

Here we present the first quantum homodyne detector on a silicon chip. We demonstrate all of the characteristics required for detection of quantum states: high speed, signal-to-noise ratio, and common-mode rejection ratio.

Conference on Lasers and Electro-Optics•Jan 1, 2017•3 citations

Production and analysis of qubit entanglement on a silicon photonic chip

Joshua W. Silverstone, Raffaele Santagati, Damien Bonneau +3 more

Silicon quantum photonics promises to take quantum optics to the large scale, where single photons carry the quantum information which can accelerate difficult computational problems, provide perfectly secure communication, or allow high-accuracy measurements. The silicon photonics platform offers miniature, high-yield, and high-performance photonics which are integrable with CMOS electronics and telecommunications-band optics. To date, only non-scalable photon-pair sources, based on spontaneous four-wave mixing (SFWM) in straight silicon waveguides have been shown to interfere [1]. Until now, single-photon experiments in silicon [2] have exclusively used an off-chip apparatus, such as a silica arrayed waveguide grating, to control and manipulate photon frequency. We present a silicon-on-insulator quantum photonic device (Fig. 1a) able to generate and analyse two maximally entangled qubits. We use this device to demonstrate high-visibility quantum interferencebetween resonant SFWM sources (analogous to [1]), phase-stable frequency-selection, and quantum state tomography. We varied the phase  to obtain the fringes shown in Fig. 1b, with a visibility of 96.8%. This high visibility indicates that the two microring sources are substantially identical. We setup the entangled state via the on-chip 17-dB extinction filters, and used quantum state tomography to analyse it (Fig. 1c). We measured a fidelity of 0.8. This is the first time an entangled state of photonic qubits has been both generated and analysed on-chip, and this generation has been done in a way which is scalable to larger photon number. These results represent a new step towards fully silicon-integrated quantum photonics.

•Sep 1, 2014•0 citations

Integrated photonic platform with high-speed entanglement generation and witnessing

Gong Zhang, Chao Wang, Koon Tong Goh +10 more

High-speed generation and efficient entanglement detection on a photonic chip are essential for quantum information applications but hard to achieve due to common photonic chips’ material properties and limited component performance. In this work, we experimentally demonstrate an entanglement witness on a silicon photonic chip, with multi-rail single-photon entanglement generation based on decoy-state techniques. The detection is based on balanced homodyne detectors on the same photonic chip with a bandwidth of up to 12.5 GHz, which allows room-temperature operation. A loss-equivalent analysis method compensates for optical losses and system noises. Experimental results quantify an entangled state fidelity of 92% in quantum state tomography and a Clauser–Horne–Shimony–Holt violation lower bound of 2.59. These results establish a viable path toward fully integrated, high-bandwidth, room-temperature quantum photonic systems, with potential applications in on-chip quantum optics and quantum random number generation.

arXiv:2510.04534•Optica•Sep 19, 2025•3 citations

Integrated Gbps quantum random number generator with real-time extraction based on homodyne detection

Leilei Huang, Hongyi Zhou

High-speed quantum random number generators are highly demanded in cryptographic systems, whose bottleneck lies in the ease of implementation and the efficiency of real-time post-processing. Based on homodyne detection of a coherent state, we realize a compact Gbps real-time quantum random number generator with a silica planar light circuit. We integrate all the optical and electrical modules into a stand-alone device, use standard low-cost components, and make the whole system simple and robust. Homodyne detection and real-time hashing extraction circuits are built into compact electronics with a final generation rate of 1 Gbps. Our demonstration shows an economic, compact, robust, and high-speed quantum random number generator available for immediate commercialization.

Journal of the Optical Society of America B•Feb 28, 2019•27 citations
Optical homodyne detection has found use as a characterisation tool in a range of quantum technologies. So far implementations have been limited to bulk optics. Here we present the optical integration of a homodyne detector onto a silicon photonics chip. The resulting device operates at high speed, up 150 MHz, it is compact and it operates with low noise, quantified with 11 dB clearance between shot noise and electronic noise. We perform on-chip quantum tomography of coherent states with the detector and show that it meets the requirements for characterising more general quantum states of light. We also show that the detector is able to produce quantum random numbers at a rate of 1.2 Gbps, by measuring the vacuum state of the electromagnetic field and applying off-line post processing. The produced random numbers pass all the statistical tests provided by the NIST test suite.
Summary form only given. The homodyne detector is a primitive element in many quantum optics experiments. It is primarily a characterization device, used for measuring the quantum state of the electromagnetic field[1]. Quantum integrated photonics[2], in which optical sources, circuits, and detectors are monolithically integrated on a semiconductor chip, provides a compact, scalable, platform in which to implement quantum devices like the homodyne detector. Here, we present a homodyne detector integrated in silicon and use it to generate quantum random numbers.
Silicon quantum photonics promises to take quantum optics to the large scale, where single photons carry the quantum information which can accelerate difficult computational problems, provide perfectly secure communication, or allow high-accuracy measurements. The silicon photonics platform offers miniature, high-yield, and high-performance photonics which are integrable with CMOS electronics and telecommunications-band optics. To date, only non-scalable photon-pair sources, based on spontaneous four-wave mixing (SFWM) in straight silicon waveguides have been shown to interfere [1]. Until now, single-photon experiments in silicon [2] have exclusively used an off-chip apparatus, such as a silica arrayed waveguide grating, to control and manipulate photon frequency. We present a silicon-on-insulator quantum photonic device (Fig. 1a) able to generate and analyse two maximally entangled qubits. We use this device to demonstrate high-visibility quantum interferencebetween resonant SFWM sources (analogous to [1]), phase-stable frequency-selection, and quantum state tomography. We varied the phase  to obtain the fringes shown in Fig. 1b, with a visibility of 96.8%. This high visibility indicates that the two microring sources are substantially identical. We setup the entangled state via the on-chip 17-dB extinction filters, and used quantum state tomography to analyse it (Fig. 1c). We measured a fidelity of 0.8. This is the first time an entangled state of photonic qubits has been both generated and analysed on-chip, and this generation has been done in a way which is scalable to larger photon number. These results represent a new step towards fully silicon-integrated quantum photonics.
High-speed generation and efficient entanglement detection on a photonic chip are essential for quantum information applications but hard to achieve due to common photonic chips’ material properties and limited component performance. In this work, we experimentally demonstrate an entanglement witness on a silicon photonic chip, with multi-rail single-photon entanglement generation based on decoy-state techniques. The detection is based on balanced homodyne detectors on the same photonic chip with a bandwidth of up to 12.5 GHz, which allows room-temperature operation. A loss-equivalent analysis method compensates for optical losses and system noises. Experimental results quantify an entangled state fidelity of 92% in quantum state tomography and a Clauser–Horne–Shimony–Holt violation lower bound of 2.59. These results establish a viable path toward fully integrated, high-bandwidth, room-temperature quantum photonic systems, with potential applications in on-chip quantum optics and quantum random number generation.
High-speed quantum random number generators are highly demanded in cryptographic systems, whose bottleneck lies in the ease of implementation and the efficiency of real-time post-processing. Based on homodyne detection of a coherent state, we realize a compact Gbps real-time quantum random number generator with a silica planar light circuit. We integrate all the optical and electrical modules into a stand-alone device, use standard low-cost components, and make the whole system simple and robust. Homodyne detection and real-time hashing extraction circuits are built into compact electronics with a final generation rate of 1 Gbps. Our demonstration shows an economic, compact, robust, and high-speed quantum random number generator available for immediate commercialization.