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 Lasers and Electro-Optics

Towards noise robustness in optimal quantum control experiments

Andreas F. Bartelt, Matthias Roth, Manjusha Mehendale, HERSCHEL A. RABITZ

Published Jan 1, 2005• 0 citations
Publisher

Abstract

Optimal control operates in the presence of noise. Enhancement of the signal to noise ratio through optimized control is demonstrated for two condensed phase systems: the concept was demonstrated for second harmonic generation (SHG) in a nonlinear optical crystal and stimulated emission pumping (SEP) in a dye solution. Management of inherent control noise in the manipulation of quantum system is a subject of basic concern in virtually all applications of manipulating quantum dynamics phenomena. The cases of SHG and SEP in this work serve as illustrations of this capability. For control lasers operating at a kHz repetition rate, readily available electronics can handle this data stream.

DOI
10.1109/cleo.2005.201826

Related papers

Assuring robustness to noise in optimal quantum control experiments

Andreas F. Bartelt, Matthias Roth, Manjusha Mehendale +1 more

Closed-loop optimal quantum control experiments operate in the inherent presence of laser noise. In many applications, attaining high quality results [i.e., a high signal-to-noise $(S∕N)$ ratio for the optimized objective] is as important as producing a high control yield. Enhancement of the $S∕N$ ratio will typically be in competition with the mean signal, however, the latter competition can be balanced by biasing the optimization experiments towards higher mean yields while retaining a good $S∕N$ ratio. Other strategies can also direct the optimization to reduce the standard deviation of the statistical signal distribution. The ability to enhance the $S∕N$ ratio through an optimized choice of the control is demonstrated for two condensed phase model systems: second harmonic generation in a nonlinear optical crystal and stimulated emission pumping in a dye solution.

Physical Review A•Jun 15, 2005•22 citations

Optimal control of quantum systems: Origins of inherent robustness to control field fluctuations

HERSCHEL A. RABITZ

The impact of control field fluctuations on the optimal manipulation of quantum dynamics phenomena is investigated. The quantum system is driven by an optimal control field, with the physical focus on the evolving expectation value of an observable operator. A relationship is shown to exist between the system dynamics and the control field fluctuations, wherein the process of seeking optimal performance assures an inherent degree of system robustness to such fluctuations. The presence of significant field fluctuations breaks down the evolution of the observable expectation value into a sequence of partially coherent robust steps. Robustness occurs because the optimization process reduces sensitivity to noise-driven quantum system fluctuations by taking advantage of the observable expectation value being bilinear in the evolution operator and its adjoint. The consequences of this inherent robustness are discussed in the light of recent experiments and numerical simulations on the optimal control of quantum phenomena. The analysis in this paper bodes well for the future success of closed-loop quantum optimal control experiments, even in the presence of reasonable levels of field fluctuations.

Physical Review A•Dec 13, 2002•37 citations

Robust control of quantum systems and in the presence of field fluctuations

HERSCHEL A. RABITZ

The impact of control field fluctuations on the optimal manipulation of quantum dynamics phenomena is investigated. The presence of significant field fluctuations is shown to break down the evolution into a sequence of partially coherent robust steps. Robustness occurs because the optimization process reduces sensitivity to noise-driven quantum system fluctuations. This process takes advantage of the observable expectation value being bilinear in the evolution operator and its adjoint. The consequences of this inherent robustness bodes well for the future success of closed loop quantum optimal control experiments.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 9, 2003•0 citations

Passive laser power stabilization in a broadband noise spectrum via a second-harmonic generator

Nanjing Jiao, Ruixin Li, Bingnan An +4 more

An extremely conspicuous passive power noise stabilization is the first, to the best of our knowledge, discovered in a cavity-enhanced second-harmonic generation (SHG) process. Differing from the SHG as a buffer reservoir, the stronger strength of the nonlinear interaction pushes the power noise suppression level to a higher value and exhibits a broadband noise reduction performance due to the mechanism of dynamic pump suppression in the SHG process. The noise is suppressed to near shot noise limit (SNL) among the kHz to MHz frequency range, accompanied by a maximum noise reduction of 35 dB. A comprehensive demonstration indicates that the nonlinear interaction has no function on the phase noise of fundamental and harmonic waves. A theoretical model is also established that is consistent well with the experimental results. The methodology is beneficial to multiple optical metrology experiments.

Optics Letters•May 24, 2024•10 citations

LQG control of an optical squeezer

S. Z. Sayed Hassen, Ian R. Petersen, Elanor H. Huntington +2 more

In this paper, we consider the application of linear quadratic Gaussian (LQG) control to the problem of optimizing the level of squeezing in one of the quadratures of an optical field. Squeezed states of light can be generated when two optical fields (at fundamental and second-harmonic frequencies) interact in an optical cavity in the presence of a second-order nonlinear crystal. Our system is an optical squeezer which is modelled as a nonlinear quantum system. Suitable models for the quantum and classical noises present in the system are used and laser phase noise which arises due to mechanical vibration of the mirror(s) in the beam path is modeled as (approximately) integrated white noise. An LQG controller is synthesized and the closed loop system is simulated to validate our design.

Proceedings of the ... American Control Conference/Proceedings of the American Control Conference•Jun 1, 2010•16 citations

Optimal Control of Homonuclear Spin Dynamics Subject to Relaxation

Brent Pryor, Navin Khaneja

In this manuscript, we investigate an optimal control problem that arises in connection with the manipulation of open quantum system dynamics. Specifically, we examine a system arising in homonuclear spectroscopy experiments, and show an optimal control can be found by first relaxing the constraint imposed on the control, and then using the solution to the relaxed control problem to solve the original problem. In the context of coherent spectroscopy, this solution translates into the maximum signal to noise ratio that can be obtained in an experiment

IEEE Conference on Decision and Control (CDC)•Dec 1, 2006•2 citations
Optimal control operates in the presence of noise. Enhancement of the signal to noise ratio through optimized control is demonstrated for two condensed phase systems: the concept was demonstrated for second harmonic generation (SHG) in a nonlinear optical crystal and stimulated emission pumping (SEP) in a dye solution. Management of inherent control noise in the manipulation of quantum system is a subject of basic concern in virtually all applications of manipulating quantum dynamics phenomena. The cases of SHG and SEP in this work serve as illustrations of this capability. For control lasers operating at a kHz repetition rate, readily available electronics can handle this data stream.
Closed-loop optimal quantum control experiments operate in the inherent presence of laser noise. In many applications, attaining high quality results [i.e., a high signal-to-noise (S∕N)(S∕N)(S∕N) ratio for the optimized objective] is as important as producing a high control yield. Enhancement of the S∕NS∕NS∕N ratio will typically be in competition with the mean signal, however, the latter competition can be balanced by biasing the optimization experiments towards higher mean yields while retaining a good S∕NS∕NS∕N ratio. Other strategies can also direct the optimization to reduce the standard deviation of the statistical signal distribution. The ability to enhance the S∕NS∕NS∕N ratio through an optimized choice of the control is demonstrated for two condensed phase model systems: second harmonic generation in a nonlinear optical crystal and stimulated emission pumping in a dye solution.
The impact of control field fluctuations on the optimal manipulation of quantum dynamics phenomena is investigated. The quantum system is driven by an optimal control field, with the physical focus on the evolving expectation value of an observable operator. A relationship is shown to exist between the system dynamics and the control field fluctuations, wherein the process of seeking optimal performance assures an inherent degree of system robustness to such fluctuations. The presence of significant field fluctuations breaks down the evolution of the observable expectation value into a sequence of partially coherent robust steps. Robustness occurs because the optimization process reduces sensitivity to noise-driven quantum system fluctuations by taking advantage of the observable expectation value being bilinear in the evolution operator and its adjoint. The consequences of this inherent robustness are discussed in the light of recent experiments and numerical simulations on the optimal control of quantum phenomena. The analysis in this paper bodes well for the future success of closed-loop quantum optimal control experiments, even in the presence of reasonable levels of field fluctuations.
The impact of control field fluctuations on the optimal manipulation of quantum dynamics phenomena is investigated. The presence of significant field fluctuations is shown to break down the evolution into a sequence of partially coherent robust steps. Robustness occurs because the optimization process reduces sensitivity to noise-driven quantum system fluctuations. This process takes advantage of the observable expectation value being bilinear in the evolution operator and its adjoint. The consequences of this inherent robustness bodes well for the future success of closed loop quantum optimal control experiments.
An extremely conspicuous passive power noise stabilization is the first, to the best of our knowledge, discovered in a cavity-enhanced second-harmonic generation (SHG) process. Differing from the SHG as a buffer reservoir, the stronger strength of the nonlinear interaction pushes the power noise suppression level to a higher value and exhibits a broadband noise reduction performance due to the mechanism of dynamic pump suppression in the SHG process. The noise is suppressed to near shot noise limit (SNL) among the kHz to MHz frequency range, accompanied by a maximum noise reduction of 35 dB. A comprehensive demonstration indicates that the nonlinear interaction has no function on the phase noise of fundamental and harmonic waves. A theoretical model is also established that is consistent well with the experimental results. The methodology is beneficial to multiple optical metrology experiments.
In this paper, we consider the application of linear quadratic Gaussian (LQG) control to the problem of optimizing the level of squeezing in one of the quadratures of an optical field. Squeezed states of light can be generated when two optical fields (at fundamental and second-harmonic frequencies) interact in an optical cavity in the presence of a second-order nonlinear crystal. Our system is an optical squeezer which is modelled as a nonlinear quantum system. Suitable models for the quantum and classical noises present in the system are used and laser phase noise which arises due to mechanical vibration of the mirror(s) in the beam path is modeled as (approximately) integrated white noise. An LQG controller is synthesized and the closed loop system is simulated to validate our design.
In this manuscript, we investigate an optimal control problem that arises in connection with the manipulation of open quantum system dynamics. Specifically, we examine a system arising in homonuclear spectroscopy experiments, and show an optimal control can be found by first relaxing the constraint imposed on the control, and then using the solution to the relaxed control problem to solve the original problem. In the context of coherent spectroscopy, this solution translates into the maximum signal to noise ratio that can be obtained in an experiment