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

'Slow'- and 'fast'-light in a single ring-resonator circuit: theory, experimental observations, and sensing applications

Henri P. Uranus, Leimeng Zhuang, Chris G. H. Roeloffzen, H.J.W.M. Hoekstra

Published Aug 6, 2007• 0 citations
OpenAlex

Abstract

Transfer matrix method (TMM) was used to study the phenomena of ‘slow’- and ‘fast’-light in a single two-port ring-resonator (TPRR) circuit theoretically. Their classifications into ‘slow’- and ‘fast’-light with negative and positive group velocity (v_g), where ‘slow’ means |v_g|<c and ‘fast’ means |v_g|>c, will be introduced. The role of such phenomena in controlling light-matter interaction and pulse delay/’advancement’ will be discussed. Direct experimental observations on pulse temporal behaviors in the regimes of ‘slow’- and ‘fast’-light with negative and positive v_g will be demonstrated, showing large and small pulse ‘advancement’ and delay, respectively. Pulse splitting phenomenon as a transition from a highly delayed to a highly ‘advanced’ pulse and vice versa, will also be experimentally demonstrated. Theoretical simulations on the pulse delay and ‘advancement’ based on the TMM and Fourier transform, which show a good qualitative agreement to the experimental results, will also be presented. The exploitation of ‘slow’-light, either with positive or negative v_g for enhancing light-matter interaction will be discussed through evaluating their effects to the performance of integrated-optical refractometric sensor. It will be shown that when the light is ‘slow’, either with negative or positive v_g, there is enhancement of the sensor sensitivity. An integrated-optical sensor which exploits such properties and exhibits sensitivity of one order better than the present day state-of-the-art commercial Mach-Zehnder interferometer refractometric sensor, will be presented.

Related papers

Modeling of Loss-Induced Superluminal and Negative Group Velocity in Two-Port Ring-Resonator Circuits

Henri P. Uranus, H.J.W.M. Hoekstra

The group velocity vgof light in two-port ring- resonator (TPRR) circuits with loss is theoretically studied. We point out four possible operation regimes, i.e., "slow" light with positive vg, "slow" light with negative vg, "fast" light with negative vg, and "fast" light with positive vg, where "slow" means |vg|g| > c, with c denoting the velocity of light in vacuum. The temporal behavior of pulses passing through the TPRR for the four operation regimes and the potential of "slow" light TPRR either with positive or negative vgfor sensing applications are also discussed.

Journal of Lightwave Technology•Sep 1, 2007•34 citations

Direct Experimental Observation of Pulse Temporal Behavior in Integrated-Optical Ring-Resonator with Negative Group Velocity

Henri P. Uranus, Leimeng Zhuang, Chris G. H. Roeloffzen +1 more

Abstract: We report a direct experimental observation of pulse temporal behavior in an integrated optical two-port ring-resonator circuit as a function of coupling strength, including the transition across the critical coupling point. We demonstrate the observation of pulse ‘advancement’ in the negative vg regime and pulse delay in the positive vg regime. We also observed a smooth transition of the pulse shape from highly negative to highly positive vg (or vice versa) through a pulse splitting phenomenon. The observed phenomena agree well to theoretical simulations.

Journal of Lightwave Technology•Jan 1, 2007•3 citations

Numerical observations of negative group velocity in a two-port ring-resonator circuit and its potential for sensing applications

Henri P. Uranus, H.J.W.M. Hoekstra

A two-port ring-resonator circuit is studied theoretically. It is shown that superluminal and negative group velocity (vg) phenomena can occur in both a passive two-port ring-resonator circuit with loss and an active one with gain. We present numerical observations of temporal behavior of a Gaussian pulse passing through circuits having such properties. We also show that when the negative vg is ‘slow’ (|vg|<<c), there is enhanced sensitivity of the phase shift to the ring effective index changes, which suggests its potential for highly sensitive optical sensing applications.

IEEE Lasers and Electro-Optics Society Annual Meeting (LEOS)•Dec 1, 2006•0 citations

Experimental observations of the transition from fast light to slow light in a side-coupled ring resonator

Yundong Zhang, Xuenan Zhang, Xiaoqi Liu +2 more

We report the experimental observation of dispersion transition from abnormal dispersion (fast light) to normal dispersion (slow light) in a side-coupled ring resonator. We reveal that the transition from fast light to slow light can occur, when the tuned loss of the resonator results in the experience from the undercoupled regime to the overcoupled regime. Also, we experimentally fabricate the fiber side-coupled ring resonator, and measure the group delay of the resonator by coupling the resonator to a fiber Mach-Zehnder interferometer (MZI). The measured experimental results demonstrate the dispersion transition, and are in good agreement with the corresponding theoretical results. The sidecoupled resonator with the tunable dispersion (group delay) can exploited for optical storage devices, slow light Fourier transform (FT) interferometric spectrometers, white light cavities (WLCs), optical switches, optical routers, and optical sensors.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Feb 21, 2014•0 citations

Slow and fast light in multiple-beam interferometers, mono- and multi-layer systems

A. Sánchez-Meroño

This Thesis lies within the field of Slow and Fast Light (SFL) technologies, which are currently receiving much attention because of their interesting applications, ranging from optical information processing to enhanced precision sensing and interferometry. These technologies are based on systems that exhibit steep positive dispersion to propagate a light pulse at group velocity well below the speed of light in vacuum (slow light) or steep negative dispersion to achieve pulse propagation at superluminal or even at negative group velocity (fast light). SFL effects thus arise in a myriad of materials exhibiting spectral resonances. Current efforts in this field are mainly focused on the manipulation of material gain or absorption resonances by nonlinear optical processes (material SFL) or on the optimization of photonic band-gap structures, without substantial material dispersion, but where structural dispersion comes as a result of the coupling between the light wavelength and the characteristic length of the system (structural SFL). This Thesis focuses on the theoretical and experimental analysis of electromagnetic pulse propagation with abnormal group velocities in two kind of linear and passive devices. In the first part of the Thesis a new system exhibiting structural SFL is demonstrated. It deals with multiple-beam interferometers and provides a comprehensive study of the arising of SFL in this system devoid of photonic band gaps. A theoretical model that fully describes the allowed pulse propagation regimes and its performance in terms of both the interferometer's and the pulse characteristics is developed. Considering amplitude modulated pulses, the capabilities and limitations of SFL effects in this kind of system are retrieved by quantifying typical figures of merit like fractional delay, pulse distortion and Delay-Bandwidth Product. The theoretical framework is valid for any frequency region and the model predictions are probed by performing experiments in the radiofrequency range and through exact numerical simulations in the optical range. The simplest interferometer, with only two branches, is first considered since it is widely used in actual communication systems. It is analytically demonstrated that slow light cannot possibly be sustained and that the total attenuation drives the changes in the pulse propagation regimes. By increasing the number of branches, group delay tuning from slow to fast light regimes occurs if the optical length of one of the branches is slightly changed. In the second part of the Thesis, the ability of mono- and multilayer structures to speed up or slow down electromagnetic pulses is investigated, with special emphasis on their reflection properties. Namely, Distributed Bragg Reflectors (DBRs) and Fabry-Perot filters, common in today's communication systems, are examined. These structures were fabricated to operate in the microwave and in the radiofrequency range with the aim of confirming theoretical predictions. Experimental results of their frequency- and time-domain characterization are compared with simulations. An advantage of operating in these frequency ranges is that the transmission and reflection phase function can be measured with a two port vector network analyzer. Such a simple measurement of this key function that determines the pulse propagation regime cannot be directly performed in the optical range. Moreover, microstrip DBRs were designed and their potential application as a negative group-delay circuit to improve the efficiency of feedforward amplifiers, which are commonly used for cancelling inherent distortion in microwave amplifiers, is explored.

•Apr 21, 2015•0 citations

Pulse Transmission across a Single Optical Ring-Resonator with Negative Group Velocity: Theory and Experiment

Henri P. Uranus, Leimeng Zhuang, Chris G. H. Roeloffzen +1 more

We study pulse transmission across a single optical ring-resonator circuit theoretically. The theory is supported by experimental measurements. From the study, we discuss intuitively the fulfillment of the causality rules in negative delay phenomenon, which occurs when the circuit possesses a negative group velocity.

IEEE PhotonicsGlobal•Dec 1, 2008•1 citation
Transfer matrix method (TMM) was used to study the phenomena of ‘slow’- and ‘fast’-light in a single two-port ring-resonator (TPRR) circuit theoretically. Their classifications into ‘slow’- and ‘fast’-light with negative and positive group velocity (v_g), where ‘slow’ means |v_g|<c and ‘fast’ means |v_g|>c, will be introduced. The role of such phenomena in controlling light-matter interaction and pulse delay/’advancement’ will be discussed. Direct experimental observations on pulse temporal behaviors in the regimes of ‘slow’- and ‘fast’-light with negative and positive v_g will be demonstrated, showing large and small pulse ‘advancement’ and delay, respectively. Pulse splitting phenomenon as a transition from a highly delayed to a highly ‘advanced’ pulse and vice versa, will also be experimentally demonstrated. Theoretical simulations on the pulse delay and ‘advancement’ based on the TMM and Fourier transform, which show a good qualitative agreement to the experimental results, will also be presented. The exploitation of ‘slow’-light, either with positive or negative v_g for enhancing light-matter interaction will be discussed through evaluating their effects to the performance of integrated-optical refractometric sensor. It will be shown that when the light is ‘slow’, either with negative or positive v_g, there is enhancement of the sensor sensitivity. An integrated-optical sensor which exploits such properties and exhibits sensitivity of one order better than the present day state-of-the-art commercial Mach-Zehnder interferometer refractometric sensor, will be presented.
The group velocity vgof light in two-port ring- resonator (TPRR) circuits with loss is theoretically studied. We point out four possible operation regimes, i.e., "slow" light with positive vg, "slow" light with negative vg, "fast" light with negative vg, and "fast" light with positive vg, where "slow" means |vg|g| > c, with c denoting the velocity of light in vacuum. The temporal behavior of pulses passing through the TPRR for the four operation regimes and the potential of "slow" light TPRR either with positive or negative vgfor sensing applications are also discussed.
Abstract: We report a direct experimental observation of pulse temporal behavior in an integrated optical two-port ring-resonator circuit as a function of coupling strength, including the transition across the critical coupling point. We demonstrate the observation of pulse ‘advancement’ in the negative vg regime and pulse delay in the positive vg regime. We also observed a smooth transition of the pulse shape from highly negative to highly positive vg (or vice versa) through a pulse splitting phenomenon. The observed phenomena agree well to theoretical simulations.
A two-port ring-resonator circuit is studied theoretically. It is shown that superluminal and negative group velocity (vg) phenomena can occur in both a passive two-port ring-resonator circuit with loss and an active one with gain. We present numerical observations of temporal behavior of a Gaussian pulse passing through circuits having such properties. We also show that when the negative vg is ‘slow’ (|vg|<<c), there is enhanced sensitivity of the phase shift to the ring effective index changes, which suggests its potential for highly sensitive optical sensing applications.
We report the experimental observation of dispersion transition from abnormal dispersion (fast light) to normal dispersion (slow light) in a side-coupled ring resonator. We reveal that the transition from fast light to slow light can occur, when the tuned loss of the resonator results in the experience from the undercoupled regime to the overcoupled regime. Also, we experimentally fabricate the fiber side-coupled ring resonator, and measure the group delay of the resonator by coupling the resonator to a fiber Mach-Zehnder interferometer (MZI). The measured experimental results demonstrate the dispersion transition, and are in good agreement with the corresponding theoretical results. The sidecoupled resonator with the tunable dispersion (group delay) can exploited for optical storage devices, slow light Fourier transform (FT) interferometric spectrometers, white light cavities (WLCs), optical switches, optical routers, and optical sensors.
This Thesis lies within the field of Slow and Fast Light (SFL) technologies, which are currently receiving much attention because of their interesting applications, ranging from optical information processing to enhanced precision sensing and interferometry. These technologies are based on systems that exhibit steep positive dispersion to propagate a light pulse at group velocity well below the speed of light in vacuum (slow light) or steep negative dispersion to achieve pulse propagation at superluminal or even at negative group velocity (fast light). SFL effects thus arise in a myriad of materials exhibiting spectral resonances. Current efforts in this field are mainly focused on the manipulation of material gain or absorption resonances by nonlinear optical processes (material SFL) or on the optimization of photonic band-gap structures, without substantial material dispersion, but where structural dispersion comes as a result of the coupling between the light wavelength and the characteristic length of the system (structural SFL). This Thesis focuses on the theoretical and experimental analysis of electromagnetic pulse propagation with abnormal group velocities in two kind of linear and passive devices. In the first part of the Thesis a new system exhibiting structural SFL is demonstrated. It deals with multiple-beam interferometers and provides a comprehensive study of the arising of SFL in this system devoid of photonic band gaps. A theoretical model that fully describes the allowed pulse propagation regimes and its performance in terms of both the interferometer's and the pulse characteristics is developed. Considering amplitude modulated pulses, the capabilities and limitations of SFL effects in this kind of system are retrieved by quantifying typical figures of merit like fractional delay, pulse distortion and Delay-Bandwidth Product. The theoretical framework is valid for any frequency region and the model predictions are probed by performing experiments in the radiofrequency range and through exact numerical simulations in the optical range. The simplest interferometer, with only two branches, is first considered since it is widely used in actual communication systems. It is analytically demonstrated that slow light cannot possibly be sustained and that the total attenuation drives the changes in the pulse propagation regimes. By increasing the number of branches, group delay tuning from slow to fast light regimes occurs if the optical length of one of the branches is slightly changed. In the second part of the Thesis, the ability of mono- and multilayer structures to speed up or slow down electromagnetic pulses is investigated, with special emphasis on their reflection properties. Namely, Distributed Bragg Reflectors (DBRs) and Fabry-Perot filters, common in today's communication systems, are examined. These structures were fabricated to operate in the microwave and in the radiofrequency range with the aim of confirming theoretical predictions. Experimental results of their frequency- and time-domain characterization are compared with simulations. An advantage of operating in these frequency ranges is that the transmission and reflection phase function can be measured with a two port vector network analyzer. Such a simple measurement of this key function that determines the pulse propagation regime cannot be directly performed in the optical range. Moreover, microstrip DBRs were designed and their potential application as a negative group-delay circuit to improve the efficiency of feedforward amplifiers, which are commonly used for cancelling inherent distortion in microwave amplifiers, is explored.