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

Quantum tomography for time domain Balanced Homodyne Detection with high electronic noise

Martina Esposito, Daniele Fausti, Stefano Olivares, Fabio Benatti, Roberto Floreanini B, Fabio Novelli, Federico Cilento, Francesco Randi, F. Parmigiani

Published Jan 11, 2013• 1 citation
OpenAlex

Abstract

Here we report on the design, construction and characterization of a time domain Balanced Homodyne Detection apparatus operating in the regime of high electronic noise. The experimental setup has been commissioned by studying coherent ultrashort ( ∼ 80 fs) light pulses using Pattern-function Quantum Tomography. Furthermore, we proved that the electronic noise can be treated as a detector inefficiency showing the effectiveness of this approach by measuring light coherent states with different energies. In Quantum Mechanics the measurement of the state of a physical system implies to estimate the expectation value of any observable of the system. For a generic operator the expectation value is obtained starting from the measurement of an ensemble of observables defined “quorum ” 1. In particular, for the electromagnetic field the quorum is a continuum set of the field quadra-tures2,3. Balanced Homodyne Detection (BHD) is an experimen-tal method for measuring a discrete set of the field

Related papers

Design and characterization of wideband balanced homodyne detectors for quantum homodyne tomography

Erick Barrios Barocio

This thesis reports the realization and applications of a versatile wideband balanced homodyne detector operating in the time domain and intended for Quantum Optical Tomography. The detector can work with high repetition rate lasers used for the production and measurement of the electric field quadratures of quantum states of light. Full characterization of the detector by shot-noise measurements and by verifying its capability to reconstruct the density matrix and Wigner function of various states of interest is given. By overcoming photodiodes response mismatch, high frequency electronics issues and by choosing an appropriate optical set-up, a high level of common mode suppression (52.4dB) and a low electronic noise gave a shot-to-electronic noise ratio of I3dB for a Local Oscillator with 6.2 x 108 photons-per-pulse on a ~ 100MHz bandwidth. Results for the characterization of a single-photon Fock state are presented. An average efficiency of 56% was obtained for the generation/detection of the state.

•Jan 1, 2012•0 citations

High-stability time-domain balanced homodyne detector for ultrafast optical pulse applications

Merlin Cooper, Christoph Söller, Brian J. Smith

Low-noise, efficient, phase-sensitive time-domain optical detection is essential for foundational tests of quantum physics based on optical quantum states and the realization of numerous applications ranging from quantum key distribution to coherent classical telecommunications. Stability, bandwidth, efficiency, and signal-to-noise ratio are crucial performance parameters for effective detector operation. Here we present a high-bandwidth, low-noise, ultra-stable time-domain coherent measurement scheme based on balanced homodyne detection ideally suited to characterization of quantum and classical light fields in well-defined ultrashort optical pulse modes.

arXiv:1112.0875•Journal of Modern Optics•May 1, 2013•29 citations

Time-domain analysis of quantum states of light: noise characterization and homodyne tomography

Alessandro Zavatta, Marco Bellini, Pier Luigi Ramazza +2 more

We measured the time-domain quantum statistics of a pulsed, high-repetition-rate optical field by balanced homodyne detection. The measuring apparatus discriminates the time scales on which intrinsic quantum fluctuations prevail from those scales for which technical noise is overwhelming. A tomographic reconstruction of weak coherent states with various average photon numbers demonstrates the potential ability of the system to measure high-repetition-rate, time-resolved signals. Possible extensions to other physical situations are discussed.

Journal of the Optical Society of America B•May 1, 2002•78 citations

Mediciones de ruido en un detector balanceado homodino para la reconstrucción de la función de Wigner de estados coherentes y de vacío

Samuel Esteban Sánchez Rodríguez

The Wigner function is a quasi-probability distribution of quantum states of light that describes the probability amplitude of any state through their marginal distribution. The Wigner function can be reconstructed through quantum tomography which uses the information obtained from light quadratures to reconstruct a 3d image of the Wigner function. Light quadratures can be obtained by means of balanced homodyne detection (BHD). BHD uses a controlled interference between the quantum field to be characterized and a local oscillator, which is a coherent source with well-defined frequency and phase. The main feature of a BHD is its ability to measure extremely small noise signals, even below the quantum vacuum limit for squezeed light. To obtain precise measurements in BHD it is necessary to characterize the noise sources in the electronics of the BHD such as Johnson noise and fundamental noises such as shot noise. To characterize the noise in the BHD, time based and frequency-based measurements were performed to find the quantum to classical noise ratio (QCNR). QCNR measures the capacity of the BHD to distinguish quantum noise. A high QCNR allows us to make reliable measurements of the light quadratures. For this project we developed a circuit based on the one presented by Lang et al. in low noise balanced homodyne detector for quantum noise measurements.

•Jan 27, 2026•0 citations

Ultrasensitive pulsed, balanced homodyne detector: application to time-domain quantum measurements

Hauke Hansen, Thomas Aichele, Christian Hettich +4 more

A pulsed, balanced homodyne detector has been developed for precise measurement of the electric field quadratures of pulsed optical quantum states. A high level of common mode suppression (>85 dB) and low electronic noise (730 electrons per pulse) provide a signal-to-noise ratio of 14 dB for measurement of the quantum noise of individual pulses. Measurements at repetition rates as high as 1 MHz are possible. As a test, quantum tomography of the coherent state was performed, and the Wigner function and the density matrix were reconstructed with 99.5% fidelity. The detection system can be used for ultrarsensitive balanced detection in cw mode, e.g., for weak absorption measurements.

arXiv:quant-ph/0104084•Optics Letters•Nov 1, 2001•143 citations

Homodyne Tomography and the Reconstruction of Quantum States of Light

Giacomo Mauro D’Ariano, Lorenzo Maccone, Massimiliano Federico Sacchi

Quantum tomography is a procedure to determine the quantum state of a physical system, or equivalently, to estimate the expectation value of any operator. It consists in appropriately averaging the outcomes of the measurement results of different observables, obtained on identical copies of the same system. Alternatively, it consists in maximizing an appropriate likelihood function defined on the same data. The procedure can be also used to completely characterize an unknown apparatus. Here we focus on the electromagnetic field, where the tomographic observables are obtained from homodyne detection.

arXiv:quant-ph/0507078•IMPERIAL COLLEGE PRESS eBooks•Feb 1, 2007•8 citations
Here we report on the design, construction and characterization of a time domain Balanced Homodyne Detection apparatus operating in the regime of high electronic noise. The experimental setup has been commissioned by studying coherent ultrashort ( ∼ 80 fs) light pulses using Pattern-function Quantum Tomography. Furthermore, we proved that the electronic noise can be treated as a detector inefficiency showing the effectiveness of this approach by measuring light coherent states with different energies. In Quantum Mechanics the measurement of the state of a physical system implies to estimate the expectation value of any observable of the system. For a generic operator the expectation value is obtained starting from the measurement of an ensemble of observables defined “quorum ” 1. In particular, for the electromagnetic field the quorum is a continuum set of the field quadra-tures2,3. Balanced Homodyne Detection (BHD) is an experimen-tal method for measuring a discrete set of the field
This thesis reports the realization and applications of a versatile wideband balanced homodyne detector operating in the time domain and intended for Quantum Optical Tomography. The detector can work with high repetition rate lasers used for the production and measurement of the electric field quadratures of quantum states of light. Full characterization of the detector by shot-noise measurements and by verifying its capability to reconstruct the density matrix and Wigner function of various states of interest is given. By overcoming photodiodes response mismatch, high frequency electronics issues and by choosing an appropriate optical set-up, a high level of common mode suppression (52.4dB) and a low electronic noise gave a shot-to-electronic noise ratio of I3dB for a Local Oscillator with 6.2 x 108 photons-per-pulse on a ~ 100MHz bandwidth. Results for the characterization of a single-photon Fock state are presented. An average efficiency of 56% was obtained for the generation/detection of the state.
Low-noise, efficient, phase-sensitive time-domain optical detection is essential for foundational tests of quantum physics based on optical quantum states and the realization of numerous applications ranging from quantum key distribution to coherent classical telecommunications. Stability, bandwidth, efficiency, and signal-to-noise ratio are crucial performance parameters for effective detector operation. Here we present a high-bandwidth, low-noise, ultra-stable time-domain coherent measurement scheme based on balanced homodyne detection ideally suited to characterization of quantum and classical light fields in well-defined ultrashort optical pulse modes.
We measured the time-domain quantum statistics of a pulsed, high-repetition-rate optical field by balanced homodyne detection. The measuring apparatus discriminates the time scales on which intrinsic quantum fluctuations prevail from those scales for which technical noise is overwhelming. A tomographic reconstruction of weak coherent states with various average photon numbers demonstrates the potential ability of the system to measure high-repetition-rate, time-resolved signals. Possible extensions to other physical situations are discussed.
The Wigner function is a quasi-probability distribution of quantum states of light that describes the probability amplitude of any state through their marginal distribution. The Wigner function can be reconstructed through quantum tomography which uses the information obtained from light quadratures to reconstruct a 3d image of the Wigner function. Light quadratures can be obtained by means of balanced homodyne detection (BHD). BHD uses a controlled interference between the quantum field to be characterized and a local oscillator, which is a coherent source with well-defined frequency and phase. The main feature of a BHD is its ability to measure extremely small noise signals, even below the quantum vacuum limit for squezeed light. To obtain precise measurements in BHD it is necessary to characterize the noise sources in the electronics of the BHD such as Johnson noise and fundamental noises such as shot noise. To characterize the noise in the BHD, time based and frequency-based measurements were performed to find the quantum to classical noise ratio (QCNR). QCNR measures the capacity of the BHD to distinguish quantum noise. A high QCNR allows us to make reliable measurements of the light quadratures. For this project we developed a circuit based on the one presented by Lang et al. in low noise balanced homodyne detector for quantum noise measurements.
A pulsed, balanced homodyne detector has been developed for precise measurement of the electric field quadratures of pulsed optical quantum states. A high level of common mode suppression (>85 dB) and low electronic noise (730 electrons per pulse) provide a signal-to-noise ratio of 14 dB for measurement of the quantum noise of individual pulses. Measurements at repetition rates as high as 1 MHz are possible. As a test, quantum tomography of the coherent state was performed, and the Wigner function and the density matrix were reconstructed with 99.5% fidelity. The detection system can be used for ultrarsensitive balanced detection in cw mode, e.g., for weak absorption measurements.
Quantum tomography is a procedure to determine the quantum state of a physical system, or equivalently, to estimate the expectation value of any operator. It consists in appropriately averaging the outcomes of the measurement results of different observables, obtained on identical copies of the same system. Alternatively, it consists in maximizing an appropriate likelihood function defined on the same data. The procedure can be also used to completely characterize an unknown apparatus. Here we focus on the electromagnetic field, where the tomographic observables are obtained from homodyne detection.