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

Conference on Precision Electromagnetic Measurements

In-situ electro-optic sampling of microwave signals applied to superconducting circuits

Shekhar Priyadarshi, Oliver Kieler, Alexander Fernández Scarioni, Judith Felgner, Abdulrahman H. A. Widaa, J. Kohlmann, J. Nissilä, Mark Bieler

Published Jul 8, 2024• 0 citations
Publisher

Abstract

We report on electro-optic sampling (EOS) of microwave signals under cryogenic conditions employing a fully fiber-coupled measurement scheme. We use this setup to characterize the time response of ultrafast photodiodes at a temperature of 4 K. We additionally integrate a Josephson Arbitrary Waveform Synthesizer (JAWS) to the EOS platform, which allows us to calibrate the EOS response, yielding traceability of the microwave measurements to a quantum standard. Finally, we determine the electrical reflection coefficient, i.e., the S11 scattering parameter, in a Niobium transmission line using EOS at different positions. Our work denotes an important step for traceable in-situ microwave measurements in superconducting circuits.

DOI
10.1109/cpem61406.2024.10646099

Related papers

In-situ electro-optic sampling of microwave signals under cryogenic conditions and for superconducting applications

Shekhar Priyadarshi, Ferizaj, Rinis, Oliver Kieler +8 more

We demonstrate a cryogenic electro-optic sampling (EOS) setup that allows for the measurement of microwave signals at arbitrary positions on a cryogenic chip-scale device. We use a Josephson Arbitrary Waveform Synthesizer (JAWS) to generate quantum-accurate voltage signals and measure them with the EOS setup, allowing for the calibration of its response, yielding traceability of the microwave measurements to a quantum standard. We use the EOS setup to determine the time-domain response of ultrafast cryogenic photodiodes and the electrical reflection coefficient, i.e., the S11 scattering parameter, in a superconducting transmission line. Finally, we introduce an optical femtosecond pulse source which can be used to study the fidelity of superconducting transmission lines and terminations, as well as reflections from elements like Josephson junction arrays imbedded in them.

arXiv:2411.00162•Oct 31, 2024•0 citations

Cryogenic Characterization of a Superconductor Quantum-Based Microwave Reference Source for Communications and Quantum Information

Alírio Boaventura, Justus A. Brevik, Dylan Forrest Williams +6 more

We are developing a new instrument, the RF Josephson arbitrary waveform synthesizer (RF-JAWS), for communications metrology and quantum information applications. An important aspect of the RF-JAWS design is the accurate and traceable characterization of its superconducting devices. In this article, we present a procedure for characterizing microwave superconducting devices in a cryogenic RF probe station via a vector network analyzer (VNA) calibrated with a custom cryogenic calibration kit colocated with the superconducting device under test (DUT) in the cryogenic environment. By de-embedding lossy and dispersive RF interconnects linking the superconducting DUT to the measurement apparatus at room temperature, we characterize the DUT exactly at the cryogenic on-wafer reference plane. More importantly, we operate our VNA with an external modulated source and our procedure features metrology-grade multiline thru-reflect-line calibration and absolute power and phase corrections, as opposed to the more common relative scattering-parameter correction. In addition, we apply anX-parameter model to account for impedance mismatch in cryogenic Josephson microwave sources. Our techniques are also suitable for cryogenic characterization of microwave superconducting devices for solid-state quantum computers and could help to optimize the quantum-classical interfaces in these systems.

IEEE Transactions on Applied Superconductivity•Oct 13, 2021•8 citations

Characterizing Scattering Parameters of Superconducting Quantum Integrated Circuits at Milli-Kelvin Temperatures

Manoj Stanley, Sebastian E. de Graaf, T. Hönigl-Decrinis +2 more

Designing large-scale superconducting quantum circuits involves complex microwave engineering to minimize loss, spurious reflections, and signal crosstalk. Essential for engineering more complex circuits is precise knowledge of devices’ microwave performance, which can be characterized by measuring its calibrated scattering parameters (S-parameters) at mK temperatures. In this work, we introduce a full 2-port calibrated S-parameter measurement setup which can characterize superconducting quantum integrated circuits and other RF integrated circuits operating at mK temperatures. The design and architecture of the measurement system consisting of in-house developed microwave calibration unit (MCU) housing the newly designed cryogenic calibration standards and the device under test (DUT) is discussed in detail. The measurement setup is then used to demonstrate the first calibrated S-parameter measurements of an in-house developed superconducting qubit integrated circuit at mK temperature.

IEEE Access•Jan 1, 2022•18 citations

Microwave Modeling and Characterization of Superconductive Circuits for Quantum Voltage Standard Applications at 4 K

Alírio Boaventura, Dylan Forrest Williams, Richard Chamberlin +6 more

In this article, we characterize the microwave behavior of superconductive circuits for quantum voltage standard applications at 4 K. For that, we develop a cryogenic multiline thru-reflect-line (TRL) calibration procedure to calibrate the microwave measurements at the 4 K on-wafer reference plane. We model superconductive circuits, including a Josephson array transmission line, compare simulated to TRL-calibrated measured results, and find excellent agreement up to 50 GHz.

IEEE Transactions on Applied Superconductivity•Jan 1, 2020•16 citations

Cryogenic electro-optic interconnect for superconducting devices

Tobias Jan Kippenberg, Amir Youssefi, Itay Shomroni +5 more

Abstract Encoding information onto optical fields using electro-optical modulation is the backbone of modern telecommunication networks, offering vast bandwidth and low-loss transport via optical fibers. For these reasons, optical fibers are also replacing electrical cables for short range communications within data centers. Compared to electrical coaxial cables, optical fibers also introduce two orders of magnitude smaller heat load from room to milli-Kelvin temperatures, making optical interconnects based on electro-optical modulation an attractive candidate for interfacing superconducting quantum circuits and hybrid superconducting devices. Yet, little is known about optical modulation at cryogenic temperatures. Here we demonstrate a proof-of-principle cryogenic electro-optical interconnect, showing that currently employed Ti-doped lithium niobate phase modulators are compatible with operation down to 800mK ---below the typical operation temperature of conventional microwave amplifiers based on high electron mobility transistors (HEMTs)---and maintain their room temperature Pockels coefficient. We utilize cryogenic electro-optical modulation to perform spectroscopy of a superconducting circuit optomechanical system, measuring optomechanically induced transparency (OMIT). In addition, we encode thermomechanical sidebands from the microwave domain onto an optical signal processed at room temperature. Although the currently achieved noise figure is significantly higher than that of a typical HEMT, substantial noise reduction should be attainable by harnessing recent advances in integrated modulators, by increasing the modulator length, or by using materials with a higher electro-optic coefficient, leading to noise levels on par with HEMTs. Our work highlights the potential of electro-optical modulators for massively parallel readout for emerging quantum computing or cryogenic classical computing platforms.

•Aug 17, 2020•14 citations

Traceable In Situ Microwave Power Measurement at the Cryogenic Device Plane in a Dilution Refrigerator

Paolo Panetta, Andrea Celotto, Alessandro Alocco +7 more

Accurate knowledge of the microwave power delivered to a cryogenic device under test (DUT) is essential for the characterization and operation of superconducting quantum circuits. However, this information is difficult to obtain inside dilution refrigerators because of distributed attenuation, impedance mismatch, switch-path repeatability, and temperature-dependent microwave components. This paper presents an in situ measurement method for RF power at the cryogenic device plane. The method uses a custom variable temperature stage (VTS) as a cryogenic thermal-transfer element. The TVS is alternately heated by a four-wire DC heater and by microwave power dissipated in a 20 dB pass-through attenuator. By fitting the thermal transients and comparing the corresponding steady-state temperatures, the absorbed microwave power is inferred from a directly measured DC electrical power through an AC/DC substitution procedure. The finite reflection and transmission of the attenuator are then accounted for by cryogenic two-port scattering-parameter measurements based on a switch-assisted Short--Open--Load--Reciprocal calibration, so that the result is referred to the DUT reference plane. The system is demonstrated in a dilution refrigerator with powers between -43 and -58 dBm at the DUT input plane. The demonstrated relative standard uncertainty ranges from about 2% at -43.9 dBm to about 40% at -57.6 dBm. The proposed approach combines thermal RF power transfer, cryogenic S-parameter correction, and uncertainty evaluation in a measurement architecture compatible with quantum-device experiments, providing a practical route toward traceable microwave-power calibration at millikelvin stages.

physics.ins-detCross-listedarXiv:2607.12751•Jul 15, 2026•0 citations
We report on electro-optic sampling (EOS) of microwave signals under cryogenic conditions employing a fully fiber-coupled measurement scheme. We use this setup to characterize the time response of ultrafast photodiodes at a temperature of 4 K. We additionally integrate a Josephson Arbitrary Waveform Synthesizer (JAWS) to the EOS platform, which allows us to calibrate the EOS response, yielding traceability of the microwave measurements to a quantum standard. Finally, we determine the electrical reflection coefficient, i.e., the S11 scattering parameter, in a Niobium transmission line using EOS at different positions. Our work denotes an important step for traceable in-situ microwave measurements in superconducting circuits.
We demonstrate a cryogenic electro-optic sampling (EOS) setup that allows for the measurement of microwave signals at arbitrary positions on a cryogenic chip-scale device. We use a Josephson Arbitrary Waveform Synthesizer (JAWS) to generate quantum-accurate voltage signals and measure them with the EOS setup, allowing for the calibration of its response, yielding traceability of the microwave measurements to a quantum standard. We use the EOS setup to determine the time-domain response of ultrafast cryogenic photodiodes and the electrical reflection coefficient, i.e., the S11 scattering parameter, in a superconducting transmission line. Finally, we introduce an optical femtosecond pulse source which can be used to study the fidelity of superconducting transmission lines and terminations, as well as reflections from elements like Josephson junction arrays imbedded in them.
We are developing a new instrument, the RF Josephson arbitrary waveform synthesizer (RF-JAWS), for communications metrology and quantum information applications. An important aspect of the RF-JAWS design is the accurate and traceable characterization of its superconducting devices. In this article, we present a procedure for characterizing microwave superconducting devices in a cryogenic RF probe station via a vector network analyzer (VNA) calibrated with a custom cryogenic calibration kit colocated with the superconducting device under test (DUT) in the cryogenic environment. By de-embedding lossy and dispersive RF interconnects linking the superconducting DUT to the measurement apparatus at room temperature, we characterize the DUT exactly at the cryogenic on-wafer reference plane. More importantly, we operate our VNA with an external modulated source and our procedure features metrology-grade multiline thru-reflect-line calibration and absolute power and phase corrections, as opposed to the more common relative scattering-parameter correction. In addition, we apply anX-parameter model to account for impedance mismatch in cryogenic Josephson microwave sources. Our techniques are also suitable for cryogenic characterization of microwave superconducting devices for solid-state quantum computers and could help to optimize the quantum-classical interfaces in these systems.
Designing large-scale superconducting quantum circuits involves complex microwave engineering to minimize loss, spurious reflections, and signal crosstalk. Essential for engineering more complex circuits is precise knowledge of devices’ microwave performance, which can be characterized by measuring its calibrated scattering parameters (S-parameters) at mK temperatures. In this work, we introduce a full 2-port calibrated S-parameter measurement setup which can characterize superconducting quantum integrated circuits and other RF integrated circuits operating at mK temperatures. The design and architecture of the measurement system consisting of in-house developed microwave calibration unit (MCU) housing the newly designed cryogenic calibration standards and the device under test (DUT) is discussed in detail. The measurement setup is then used to demonstrate the first calibrated S-parameter measurements of an in-house developed superconducting qubit integrated circuit at mK temperature.
Abstract Encoding information onto optical fields using electro-optical modulation is the backbone of modern telecommunication networks, offering vast bandwidth and low-loss transport via optical fibers. For these reasons, optical fibers are also replacing electrical cables for short range communications within data centers. Compared to electrical coaxial cables, optical fibers also introduce two orders of magnitude smaller heat load from room to milli-Kelvin temperatures, making optical interconnects based on electro-optical modulation an attractive candidate for interfacing superconducting quantum circuits and hybrid superconducting devices. Yet, little is known about optical modulation at cryogenic temperatures. Here we demonstrate a proof-of-principle cryogenic electro-optical interconnect, showing that currently employed Ti-doped lithium niobate phase modulators are compatible with operation down to 800mK ---below the typical operation temperature of conventional microwave amplifiers based on high electron mobility transistors (HEMTs)---and maintain their room temperature Pockels coefficient. We utilize cryogenic electro-optical modulation to perform spectroscopy of a superconducting circuit optomechanical system, measuring optomechanically induced transparency (OMIT). In addition, we encode thermomechanical sidebands from the microwave domain onto an optical signal processed at room temperature. Although the currently achieved noise figure is significantly higher than that of a typical HEMT, substantial noise reduction should be attainable by harnessing recent advances in integrated modulators, by increasing the modulator length, or by using materials with a higher electro-optic coefficient, leading to noise levels on par with HEMTs. Our work highlights the potential of electro-optical modulators for massively parallel readout for emerging quantum computing or cryogenic classical computing platforms.
Accurate knowledge of the microwave power delivered to a cryogenic device under test (DUT) is essential for the characterization and operation of superconducting quantum circuits. However, this information is difficult to obtain inside dilution refrigerators because of distributed attenuation, impedance mismatch, switch-path repeatability, and temperature-dependent microwave components. This paper presents an in situ measurement method for RF power at the cryogenic device plane. The method uses a custom variable temperature stage (VTS) as a cryogenic thermal-transfer element. The TVS is alternately heated by a four-wire DC heater and by microwave power dissipated in a 20 dB pass-through attenuator. By fitting the thermal transients and comparing the corresponding steady-state temperatures, the absorbed microwave power is inferred from a directly measured DC electrical power through an AC/DC substitution procedure. The finite reflection and transmission of the attenuator are then accounted for by cryogenic two-port scattering-parameter measurements based on a switch-assisted Short--Open--Load--Reciprocal calibration, so that the result is referred to the DUT reference plane. The system is demonstrated in a dilution refrigerator with powers between -43 and -58 dBm at the DUT input plane. The demonstrated relative standard uncertainty ranges from about 2% at -43.9 dBm to about 40% at -57.6 dBm. The proposed approach combines thermal RF power transfer, cryogenic S-parameter correction, and uncertainty evaluation in a measurement architecture compatible with quantum-device experiments, providing a practical route toward traceable microwave-power calibration at millikelvin stages.