Showing 1–25 of 25 results for author: Solano, P

Correlation Localization in Waveguide QED with Delayed Interactions

Authors: N. Vera, F. M. Quinteros, P. Barberis-Blostein, P. Solano

Abstract: We study the atom-atom correlation length in an atomic array coupled to a waveguide under the Bragg condition with delayed non-Markovian interactions caused by a finite photon propagation time. Starting from a single excited atom, the excitation partially spreads among all atoms, reaching a steady state. The remaining excitation localizes near the initially excited atom, and the atom-atom correlat… ▽ More We study the atom-atom correlation length in an atomic array coupled to a waveguide under the Bragg condition with delayed non-Markovian interactions caused by a finite photon propagation time. Starting from a single excited atom, the excitation partially spreads among all atoms, reaching a steady state. The remaining excitation localizes near the initially excited atom, and the atom-atom correlation length decreases as a power law with the interaction delay. This localization phenomenon reveals how the delay-induced non-Markovian behavior affects the correlation transport in waveguide QED systems. △ Less

Submitted 7 July, 2026; originally announced July 2026.

Comments: 9 pages, 5 figures

Continuous-variable model for arbitrary image propagation via Dirac-comb expansion in Four-Wave Mixing

Authors: Fabián Ramírez-Pacheco, Andrea Basilio-Zárate, Hans Marin Florez, Pablo Solano, Carla Hermann-Avigliano

Abstract: We develop a macroscopic continuous-variable model of stimulated four-wave mixing (4WM) yielding closed-form expressions for the mean intensity, variance, and covariance of bright probe and conjugate beams, valid for arbitrary transverse profiles of the pump and seed to all orders in the nonlinear interaction strength. The model uses a Dirac-comb expansion of the pump field, making the photon stat… ▽ More We develop a macroscopic continuous-variable model of stimulated four-wave mixing (4WM) yielding closed-form expressions for the mean intensity, variance, and covariance of bright probe and conjugate beams, valid for arbitrary transverse profiles of the pump and seed to all orders in the nonlinear interaction strength. The model uses a Dirac-comb expansion of the pump field, making the photon statistics computable pixel-by-pixel from one set of expressions. In the plane-wave limit, we recover the phase-insensitive amplifier results. Beyond this limit, the formalism explicitly demonstrates the spatial routing of information observed in earlier experiments: the seed angular spectrum is transferred to the twin-beam intensities, whereas the angular spectrum of the squared pump field is transferred to the spatial cross-correlation between the probe and conjugate. We characterize the parameter window of high-fidelity image transfer in the covariance, which is controlled by the seed-to-pump waist ratio and the interaction strength. Our model provides, in one analytical framework, a theoretical account of experiments encoding information in the bright intensities or non-locally in the spatial cross-correlations. △ Less

Submitted 19 June, 2026; originally announced June 2026.

Comments: 13 pages, 5 figures

Continuous-Variable Quantum State Tomography Enabled by Quantum Mirrors

Authors: Mariano Uria, Amaru Moya, Carla Hermann-Avigliano, Pablo Solano, Aldo Delgado

Abstract: In quantum technologies, continuous-variable systems offer advantages over their discrete counterparts. However, continuous-variable tomography suffers from exponentially growing sample complexity. We propose protocols using quantum mirrors to transfer the complete information of incident photonic states onto a control atomic system. This enables full photonic state characterization through measur… ▽ More In quantum technologies, continuous-variable systems offer advantages over their discrete counterparts. However, continuous-variable tomography suffers from exponentially growing sample complexity. We propose protocols using quantum mirrors to transfer the complete information of incident photonic states onto a control atomic system. This enables full photonic state characterization through measurements on the control atom alone, realized via kernel functions, direct wavefunction reconstruction, and pointwise Wigner function measurements. Our approach overcomes the limitations of conventional photon counting, statistical inference, and inverse transformation, providing a robust framework for benchmarking and verifying non-Gaussian states in continuous-variable quantum optics. △ Less

Submitted 2 June, 2026; originally announced June 2026.

Post-Selection Free Generation of Multi-Photon Added Coherent States

Authors: Mariano Uria, Ricardo Gutiérrez-Jáuregui, Carla Hermann-Avigliano, Pablo Solano

Abstract: Non-Gaussian quantum states are essential resources for continuous-variable quantum information processing and for metrology. Among these, multi-photon added coherent states bridge classical and non-classical behaviors; however, their generation typically relies on small photon numbers and probabilistic heralding schemes. Here, we propose a protocol for the post-selection free generation of high f… ▽ More Non-Gaussian quantum states are essential resources for continuous-variable quantum information processing and for metrology. Among these, multi-photon added coherent states bridge classical and non-classical behaviors; however, their generation typically relies on small photon numbers and probabilistic heralding schemes. Here, we propose a protocol for the post-selection free generation of high fidelity multi-photon added coherent states using the photon blockade effect in a driven Kerr nonlinear resonator, where such states emerge naturally during the dynamics. We demonstrate that high-fidelity states can be prepared by optimizing the external drive power and the interaction time. Furthermore, we show that the protocol is robust under realistic experimental conditions, achieving fidelities of $\approx 99\%$ with current state-of-the-art parameters. Our results unlock a deterministic route to complex non-classical states using well-established quantum optical platforms. △ Less

Submitted 2 June, 2026; originally announced June 2026.

Alice and Bob through a quantum mirror

Authors: M. Uria, C. Hermann-Avigliano, P. Solano, A. Delgado

Abstract: A quantum mirror is a device whose optical response, that is, transmission and reflection, can be controlled by a single qubit. Here, we propose the use of quantum mirrors as nodes in quantum networks. Propagating coherent states mediate the interaction between the control qubits of each quantum mirror. This allows implementing quantum teleportation, quantum state transfer, and entanglement swappi… ▽ More A quantum mirror is a device whose optical response, that is, transmission and reflection, can be controlled by a single qubit. Here, we propose the use of quantum mirrors as nodes in quantum networks. Propagating coherent states mediate the interaction between the control qubits of each quantum mirror. This allows implementing quantum teleportation, quantum state transfer, and entanglement swapping with success probability and average fidelity exponentially approaching unity as the average photon number increases. Furthermore, we show that quantum teleportation exhibits robustness against known sources of error, such as optical path phase difference, photon loss, and reduced quantum mirror reflectivity, presenting a promising alternative towards long-distance quantum communication. △ Less

Submitted 18 March, 2026; originally announced March 2026.

Observation of non-Markovian Radiative Phenomena in Structured Photonic Lattices

Authors: Rodrigo A. Vicencio, Fabiola G. L. Carcamo-Macaya Diego Román-Cortés, Pablo Solano

Abstract: The spectral structure of a photonic reservoir shapes radiation phenomena for embedded quantum emitters. We implement an all-optical analog to study such an effect, particularly to observe the non- Markovian radiation dynamics of an emitter coupled to two-dimensional structured reservoirs. Its dynamics is simulated by light propagating through a photonic lattice, acting as a reservoir for an adjac… ▽ More The spectral structure of a photonic reservoir shapes radiation phenomena for embedded quantum emitters. We implement an all-optical analog to study such an effect, particularly to observe the non- Markovian radiation dynamics of an emitter coupled to two-dimensional structured reservoirs. Its dynamics is simulated by light propagating through a photonic lattice, acting as a reservoir for an adjacent waveguide that mimics a coupled quantum emitter. We study radiation dynamics in square and Lieb lattices under different coupling regimes and observe how the flat band properties of the Lieb lattice significantly enhances light-matter coupling and non-Markovianity. Our platform opens a path for the experimental exploration of single-photon quantum optical phenomena in structured reservoirs to enhance light-matter interactions. △ Less

Submitted 8 July, 2025; v1 submitted 15 January, 2025; originally announced January 2025.

Comments: 6 pages, 4 figures

Journal ref: Physical Review Letters 135, 013601 (2025)

Nanofiber-based second-order atomic Bragg lattice for collectively enhanced coupling

Authors: N. Vera, P. Solano

Abstract: We propose two experimental schemes for nanofiber-based compensated optical dipole traps that optimize the collective coupling of a one-dimensional array of atoms. The created array satisfies the second-order Bragg condition ($d=λ$), facilitating constructive interference of atomic radiation into the nanofiber and generating coherent back reflections of guided modes. Both schemes use far-off reson… ▽ More We propose two experimental schemes for nanofiber-based compensated optical dipole traps that optimize the collective coupling of a one-dimensional array of atoms. The created array satisfies the second-order Bragg condition ($d=λ$), facilitating constructive interference of atomic radiation into the nanofiber and generating coherent back reflections of guided modes. Both schemes use far-off resonance light to minimize light scattering and atomic heating. Our numerical study focuses on $^{87}$Rb atoms. The results are generalizable to different atomic species and could improve the study of collective and nonlinear atomic effects. △ Less

Submitted 26 December, 2024; originally announced December 2024.

Comments: 5 pages, 5 figures

Effect of three-orifice baffles orientation on the flow and thermal-hydraulic performance: experimental analysis for net and oscillatory flows

Authors: J. Muñoz-Cámara, D. Crespí-Llorens, J. P. Solano, P. G. Vicente

Abstract: Three-orifice baffles equally spaced along a circular tube are investigated as a means for heat transfer enhancement under net, oscillatory and compound flows. An unprecedented, systematic analysis of the relative orientation of consecutive baffles -- aligned or opposed -- is accomplished to assess the changes induced on the flow structure and their impact on the thermal-hydraulic performance. The… ▽ More Three-orifice baffles equally spaced along a circular tube are investigated as a means for heat transfer enhancement under net, oscillatory and compound flows. An unprecedented, systematic analysis of the relative orientation of consecutive baffles -- aligned or opposed -- is accomplished to assess the changes induced on the flow structure and their impact on the thermal-hydraulic performance. The results cover the Nusselt number, the net and oscillatory friction factors and the instantaneous velocity fields using PIV in an experimental campaign with a 32 mm tube diameter. The study is conducted in the range of net Reynolds numbers $50 < Re_n < 1000$ and oscillatory Reynolds numbers $0 < Re_{osc}< 750$, for a dimensionless amplitude $x_0/D = 0.5$ and $Pr=65$. In absence of oscillatory flow, opposed baffles advance the transition to turbulence from $Re_n = 100$ to $50$, increasing the net friction factor (40 %) for $Re_n > 50$ and the Nusselt number (maximum of 27 %) for $Re_n < 150$. When an oscillatory flow is applied, augmentations caused by opposed baffles are only observed for $Re_n < 150$ and $Re_{osc} < 150$. Above $Re_n$, $Re_{osc}>150$, opposed baffles are not recommended for the promotion of heat transfer, owing to friction penalties. However, the chaotic mixing and lack of short-circuiting between baffles observed with flow velocimetry over a wide range of operational conditions point out the interest of this configuration to achieve plug flow. △ Less

Submitted 20 December, 2024; originally announced December 2024.

Comments: 20 pages, 16 figures

Journal ref: Applied Thermal Engineering, Volume 236, Part B, 2024, 121566

Controlling directional propagation in driven-dissipative 2D photonic lattices

Authors: Bastián Real, Pablo Solano, Carla Hermann-Avigliano

Abstract: Controlling light propagation in photonic systems fosters fundamental research and practical application. Particularly, photonic lattices allow engineering band dispersions and tailor transport features through their geometry. However, complete controllability requires external manipulation of the propagating light. Here, we present a resonant excitation scheme to observe quasi-1D and uni-directio… ▽ More Controlling light propagation in photonic systems fosters fundamental research and practical application. Particularly, photonic lattices allow engineering band dispersions and tailor transport features through their geometry. However, complete controllability requires external manipulation of the propagating light. Here, we present a resonant excitation scheme to observe quasi-1D and uni-directional propagation of light through the bulk of two-dimensional lattices. To this end, we use the highly anisotropic light propagation exhibited at the energy of saddle points in photonic bands. When multiple drives with judicious amplitudes and phases are tuned to such energy, interference effects between these drives and photonic modes result in controllable directional propagation through the bulk. Similarly, one can formed localized states with controllable localization degrees. We illustrate these effects with driven-dissipative photonic lattices. Our work highlights the importance of external drives for dynamically controlling directional light transport in lattices, a relevant feature for all-optical routing and processing in photonics. △ Less

Submitted 17 July, 2024; originally announced July 2024.

Comments: 7 pages, 5 figures

Journal ref: Optics Express 32, 26, 47458-47467 (2024)

Harnessing collective radiative phenomena on a photonic kagome lattice

Authors: Ignacio Salinas, Javier Cubillos Cornejo, Alexander Szameit, Pablo Solano, Rodrigo A. Vicencio

Abstract: Photonic lattices enable experimental exploration of transport and localization phenomena, two of the mayor goals in physics and technology. In particular, the optical excitation of some lattice sites which evanescently couple to a lattice array emulates radiation processes into structured reservoirs, a fundamental subject in quantum optics. Moreover, the simultaneous excitation of two sites simul… ▽ More Photonic lattices enable experimental exploration of transport and localization phenomena, two of the mayor goals in physics and technology. In particular, the optical excitation of some lattice sites which evanescently couple to a lattice array emulates radiation processes into structured reservoirs, a fundamental subject in quantum optics. Moreover, the simultaneous excitation of two sites simulates collective phenomena, leading to phase-controlled enhanced or suppressed radiation, namely super and subradiance. This work presents an experimental study of collective radiative processes on a photonic kagome lattice. A single or simultaneous -- in or out-of-phase -- excitation of the outlying sites controls the radiation dynamics. Specifically, we demonstrate a controlable transition between a fully localized profile at the two outlying sites and a completely dispersed state into the quasi-continuum. Our result presents photonic lattices as a platform to emulate and experimentally explore quantum optical phenomena in two-dimensional structured reservoirs, while harnessing such phenomena for controlling transport dynamics and implementing all-optical switching devices. △ Less

Submitted 31 October, 2023; originally announced October 2023.

Comments: 7 pages, 4 figures

Analytic Evolution for Complex Coupled Tight-Binding Models: Applications to Quantum Light Manipulation

Authors: Santiago Rojas-Rojas, Camila Muñoz, Edgar Barriga, Pablo Solano, Aldo Delgado, Carla Hermann-Avigliano

Abstract: We present analytic solutions to the evolution in generalized tight-binding models, which consider complex first-neighbor couplings with equal amplitude and arbitrary phases. Our findings provide a powerful tool for efficiently calculating expectation values and correlations within the system, which are otherwise difficult to compute numerically. We apply our results to relevant examples in quantu… ▽ More We present analytic solutions to the evolution in generalized tight-binding models, which consider complex first-neighbor couplings with equal amplitude and arbitrary phases. Our findings provide a powerful tool for efficiently calculating expectation values and correlations within the system, which are otherwise difficult to compute numerically. We apply our results to relevant examples in quantum light manipulation using N-port linear couplers, describing the evolution of single(multi)-mode squeezing, single photon added (subtracted) Gaussian states, and second-order site-to-site photon correlations. Significantly, our analytic results outperform standard numerical calculations. Our study paves the way for a comprehensive mathematical framework describing the spatial evolution of quantum states across a wide range of physical systems governed by the tight-binding model. △ Less

Submitted 20 November, 2023; v1 submitted 18 October, 2023; originally announced October 2023.

Comments: 18 pages, 7 figures. Includes Supplementary Material

Dynamical beats of short pulses in waveguide QED

Authors: Dianqiang Su, Yuan Jiang, Silvia Cardenas-Lopez, Ana Asenjo-Garcia, Pablo Solano, Luis A. Orozco, Yanting Zhao

Abstract: We study temporal oscillations, known as dynamical beats, developed by a propagating pulse due to its interaction with a near-resonant collective medium of $^{133}$Cs atoms randomly captured by a nanofiber-based optical lattice. A phenomenological theory provides an intuitive explanation and quantitative predictions, which are improved by an input-output theory considering multiple-scattering betw… ▽ More We study temporal oscillations, known as dynamical beats, developed by a propagating pulse due to its interaction with a near-resonant collective medium of $^{133}$Cs atoms randomly captured by a nanofiber-based optical lattice. A phenomenological theory provides an intuitive explanation and quantitative predictions, which are improved by an input-output theory considering multiple-scattering between the atoms. The results deepen our understanding of light propagation in waveguide QED, essential in time-frequency analysis and light engineering for probing, manipulating, and exploiting many-body quantum systems. △ Less

Submitted 18 April, 2023; originally announced April 2023.

Optomechanical feedback cooling of a 5 mm-long torsional mode

Authors: Dianqiang Su, Yuan Jiang, Pablo Solano, Luis A. Orozco, John Lawall, Yanting Zhao

Abstract: We report three orders of magnitude optical cooling of the fundamental torsional mode of a 5 mm-long, 550 nm diameter optical nanofiber. The rotation of the nanofiber couples to the polarization of guided laser fields. We use a weak laser probe to monitor the rotation, and use feedback to modulate the polarization of an auxiliary drive laser providing torque. Our results present a tool for the opt… ▽ More We report three orders of magnitude optical cooling of the fundamental torsional mode of a 5 mm-long, 550 nm diameter optical nanofiber. The rotation of the nanofiber couples to the polarization of guided laser fields. We use a weak laser probe to monitor the rotation, and use feedback to modulate the polarization of an auxiliary drive laser providing torque. Our results present a tool for the optomechanical control of large-scale torsional resonators, with metrological applications and potential implications for studying macroscopic objects in quantum states. △ Less

Submitted 25 January, 2023; originally announced January 2023.

Effects of environment correlations on the onset of collective decay in waveguide QED

Authors: Alberto Del Ángel, P. Solano, P. Barberis-Blostein

Abstract: We calculate the dynamics of one and two two-level atoms interacting with the electromagnetic vacuum field in the vicinity of an optical nanofiber without making either the Born or the Markov approximations. We use a constant dielectric function and the Drude-Lorentz model, observing deviations from the standard super- and sub-radiant decays. Despite the non-trivial environment correlations, we di… ▽ More We calculate the dynamics of one and two two-level atoms interacting with the electromagnetic vacuum field in the vicinity of an optical nanofiber without making either the Born or the Markov approximations. We use a constant dielectric function and the Drude-Lorentz model, observing deviations from the standard super- and sub-radiant decays. Despite the non-trivial environment correlations, we discuss the validity of approximating the speed of atom-atom communication to the group velocity of the guided field. Our work presents a deeper understanding of the validity of commonly used approximations in recent platforms for quantum optics applications in the context of waveguide QED. △ Less

Submitted 4 December, 2022; originally announced December 2022.

Comments: 10 pages, 17 figures

Dipole-dipole Interactions Through a Lens

Authors: A. Olivera, K. Sinha, P. Solano

Abstract: We study the fluctuation-mediated interactions between two atoms in the presence of an aplanatic lens, demonstrating an enhancement in their resonant dipole-dipole interaction. We derive the field propagation of the linear optical system in terms of the electromagnetic Green's tensor for an aplanatic lens. The collective internal atomic dynamics is analyzed via a Lindblad master equation, which al… ▽ More We study the fluctuation-mediated interactions between two atoms in the presence of an aplanatic lens, demonstrating an enhancement in their resonant dipole-dipole interaction. We derive the field propagation of the linear optical system in terms of the electromagnetic Green's tensor for an aplanatic lens. The collective internal atomic dynamics is analyzed via a Lindblad master equation, which allows one to characterize the dispersive and dissipative interactions between atoms. We thus demonstrate that the resonant dipole-dipole coupling between the atoms can be enhanced in the focal plane of the lens, and the lens-modified energy exchange between the atoms can create a mutual trapping potential. Our work opens new avenues for expanding dipole-dipole interactions to macroscopic scales and the experimental platforms to study them. △ Less

Submitted 1 April, 2022; originally announced April 2022.

Optical precursors in waveguide quantum electrodynamics

Authors: Silvia Cardenas-Lopez, Pablo Solano, Luis A. Orozco, Ana Asenjo-Garcia

Abstract: When a broadband signal propagates through a dispersive medium, some frequency components move faster than the center of the pulse. This leads to the appearance of precursors, transient signals that emerge from the medium earlier than the main part of the pulse and seem to propagate superluminally. Here, we investigate the microscopic origin of precursors in a minimal setup: an array of qubits cou… ▽ More When a broadband signal propagates through a dispersive medium, some frequency components move faster than the center of the pulse. This leads to the appearance of precursors, transient signals that emerge from the medium earlier than the main part of the pulse and seem to propagate superluminally. Here, we investigate the microscopic origin of precursors in a minimal setup: an array of qubits coupled to a waveguide. The linear transmission function only converges to that of a continuous medium for large qubit numbers. Nevertheless, the dispersion produced by only two qubits is enough to produce oscillatory transients. Precursors are best observed under conditions of electromagnetically-induced transparency, as the center of the pulse is significantly delayed. Under these conditions, just a single qutrit is enough to generate a precursor. Our results pave the way towards dispersion engineering of light with just a few qubits, and can be realized with superconducting qubits coupled to transmission lines or atoms coupled to optical waveguides. △ Less

Submitted 18 April, 2023; v1 submitted 2 March, 2022; originally announced March 2022.

Comments: 10 pages, 6 figures

Journal ref: Phys. Rev. Res. 5, 013133, 2023

Torsional optomechanical cooling of a nanofiber

Authors: Dianqiang Su, Pablo Solano, Jeffrey D. Wack, Luis A. Orozco, Yanting Zhao

Abstract: We demonstrate the optomechanical cooling of a tapered optical nanofiber by coupling the polarization of light to the mechanical angular momentum of the system. The coupling is enabled by birefringence in the fiber and does not make use of an optical resonator. We find evidence for cooling in the distribution of thermally driven amplitude fluctuations and the noise spectrum of the torsional modes.… ▽ More We demonstrate the optomechanical cooling of a tapered optical nanofiber by coupling the polarization of light to the mechanical angular momentum of the system. The coupling is enabled by birefringence in the fiber and does not make use of an optical resonator. We find evidence for cooling in the distribution of thermally driven amplitude fluctuations and the noise spectrum of the torsional modes. Our proof-of-principle demonstration shows cavity-less cooling of the torsional degree of freedom of a macroscopically extended nanofiber. △ Less

Submitted 28 January, 2022; v1 submitted 13 December, 2019; originally announced December 2019.

Exploratory numerical experiments with a macroscopic theory of interfacial interactions

Authors: Domenico Giordano, Pablo Solano-López, Josè Manuel Donoso

Abstract: Phenomenological theories of interfacial interactions have targeted terrestrial applications since long time and their exploitation has inspired our research programme to build up a macroscopic theory of gas-surface interactions targeting the complex phenomenology of hypersonic reentry flows as alternative to standard methods based on accommodation coefficients. The objective of this paper is the… ▽ More Phenomenological theories of interfacial interactions have targeted terrestrial applications since long time and their exploitation has inspired our research programme to build up a macroscopic theory of gas-surface interactions targeting the complex phenomenology of hypersonic reentry flows as alternative to standard methods based on accommodation coefficients. The objective of this paper is the description of methods employed and results achieved in an exploratory study, that is, the unsteady heat transfer between two solids in contact with and without interface. It is a simple numerical-demonstrator test case designed to facilitate quick numerical calculations and to bring forth already sufficiently meaningful aspects relevant to thermal protection due to the formation of the interface. The paper begins with a brief introduction on the subject matter and a review of relevant literature. Then the case is considered in which the interface is absent. The importance of tension continuity as boundary condition on the same footing of heat-flux continuity is recognised and the role of the former in governing the establishment of the temperature-difference distribution over the separation surface is explicitly shown. Evidence is given that the standard temperature-continuity boundary condition is just a particular case. Subsequently the case in which the interface is formed between the solids is analysed. The coupling among the heat-transfer equations applicable in the solids and the balance equation for the surface thermodynamic energy formulated in terms of the surface temperature is discussed. Results are illustrated for planar and cylindrical configuration; they show unequivocally that the thermal-protection action of the interface turns out to be driven exclusively by thermophysical properties of the solids and of the interface; accommodation coefficients are not needed. △ Less

Submitted 18 March, 2019; originally announced March 2019.

Comments: 21 pages, 18 figures

Journal ref: CEAS Space Journal, 9 (3), pp. 257-277, 2017

Spectral Asymmetry of Atoms in the van der Waals Potential of an Optical Nanofiber

Authors: B. D. Patterson, P. Solano, P. S. Julienne, L. A. Orozco, S. L. Rolston

Abstract: We measure the modification of the transmission spectra of cold $^{87}$Rb atoms in the proximity of an optical nanofiber (ONF). Van der Waals interactions between the atoms an the ONF surface decrease the resonance frequency of atoms closer to the surface. An asymmetric spectra of the atoms holds information of their spatial distribution around the ONF. We use a far-detuned laser beam coupled to t… ▽ More We measure the modification of the transmission spectra of cold $^{87}$Rb atoms in the proximity of an optical nanofiber (ONF). Van der Waals interactions between the atoms an the ONF surface decrease the resonance frequency of atoms closer to the surface. An asymmetric spectra of the atoms holds information of their spatial distribution around the ONF. We use a far-detuned laser beam coupled to the ONF to thermally excite atoms at the ONF surface. We study the change of transmission spectrum of these atoms as a function of heating laser power. A semi-classical phenomenological model for the thermal excitation of atoms in the atom-surface van der Waals bound states is in good agreement with the measurements. This result suggests that van der Waals potentials could be used to trap and probe atoms at few nanometers from a dielectric surfaces, a key tool for hybrid photonic-atomic quantum systems. △ Less

Submitted 4 January, 2018; originally announced January 2018.

Journal ref: Phys. Rev. A 97, 032509 (2018)

Spin-optomechanical coupling between light and a nanofiber torsional mode

Authors: Eliot F. Fenton, Adnan Khan, Pablo Solano, Luis A. Orozco, Fredrik K. Fatemi

Abstract: Light that carries linear or angular momentum can interact with a mechanical object giving rise to optomechanical effects. In particular, a photon transfers its intrinsic angular momentum to an object when the object either absorbs the photon or changes the photon polarization, as in an action/reaction force pair. Here, we present the implementation of light-induced selective resonant driving of t… ▽ More Light that carries linear or angular momentum can interact with a mechanical object giving rise to optomechanical effects. In particular, a photon transfers its intrinsic angular momentum to an object when the object either absorbs the photon or changes the photon polarization, as in an action/reaction force pair. Here, we present the implementation of light-induced selective resonant driving of the torsional mechanical modes of a single-mode tapered optical nanofiber. The nanofiber torsional mode spectrum is characterized by polarimetry, showing narrow natural resonances (Q$\approx$2,000). By sending amplitude modulated light through the nanofiber, we resonantly drive individual torsional modes as a function of the light polarization. By varying the input polarization to the fiber, we find the largest amplification of a mechanical oscillation (>35 dB) is observed when driving the system with light containing longitudinal spin on the nanofiber waist. These results present optical nanofibers as a platform suitable for quantum spin-optomechanics experiments. △ Less

Submitted 12 December, 2017; originally announced December 2017.

Alignment-dependent decay rate of an atomic dipole near an optical nanofiber

Authors: Pablo Solano, Jeffrey A. Grover, Yunlu Xu, Pablo Barberis-Blostein, Jeremy N. Munday, Luis A. Orozco, William D. Phillips, Steven L. Rolston

Abstract: We study the modification of the atomic spontaneous emission rate, i.e. Purcell effect, of $^{87}$Rb in the vicinity of an optical nanofiber ($\sim$500 nm diameter). We observe enhancement and inhibition of the atomic decay rate depending on the alignment of the induced atomic dipole relative to the nanofiber. Finite-difference time-domain simulations are in quantitative agreement with the measure… ▽ More We study the modification of the atomic spontaneous emission rate, i.e. Purcell effect, of $^{87}$Rb in the vicinity of an optical nanofiber ($\sim$500 nm diameter). We observe enhancement and inhibition of the atomic decay rate depending on the alignment of the induced atomic dipole relative to the nanofiber. Finite-difference time-domain simulations are in quantitative agreement with the measurements when considering the atoms as simple oscillating linear dipoles. This is surprising since the multi-level nature of the atoms should produce a different radiation pattern, predicting smaller modification of the lifetime than the measured ones. This work is a step towards characterizing and controlling atomic properties near optical waveguides, fundamental tools for the development of quantum photonics. △ Less

Submitted 27 April, 2017; originally announced April 2017.

Journal ref: Phys. Rev. A 99, 013822 (2019)

Near-field measurement of modal interference in optical nanofibers for sub-Angstrom radius sensitivity

Authors: Fredrik K. Fatemi, Jonathan E. Hoffman, Pablo Solano, Eliot F. Fenton, Guy Beadie, Steven L. Rolston, Luis A. Orozco

Abstract: Optical nanofibers (ONF) of subwavelength dimensions confine light in modes with a strong evanescent field that can trap, probe, and manipulate nearby quantum systems. To measure the evanescent field and propagating modes, and to optimize ONF performance, a surface probe is desirable during fabrication. We demonstrate a nondestructive measurement of light propagation in ONFs by sampling the local… ▽ More Optical nanofibers (ONF) of subwavelength dimensions confine light in modes with a strong evanescent field that can trap, probe, and manipulate nearby quantum systems. To measure the evanescent field and propagating modes, and to optimize ONF performance, a surface probe is desirable during fabrication. We demonstrate a nondestructive measurement of light propagation in ONFs by sampling the local evanescent field with a microfiber. This approach reveals the behavior of all propagating modes, and because the modal beat lengths in cylindrical waveguides depend strongly on radius, simultaneously provides exquisite sensitivity to the ONF radius. We show that our measured spatial frequencies provide a map of the average ONF radius (over a 600 micrometer window) along the 10 mm ONF waist with 40 picometer resolution and high signal-to-noise ratio. The measurements agree with scanning electron microscopy (SEM) to within SEM instrument resolution. This fast method is immune to polarization, intrinsic birefringence, mechanical vibrations, scattered light, and provides a set of constraints to protect from systematic errors in the measurements △ Less

Submitted 5 October, 2016; originally announced October 2016.

Journal ref: Optica Vol. 4, Issue 1, pp. 157-162 (2017)

Self-organization of atoms coupled to a chiral reservoir

Authors: Zachary Eldredge, Pablo Solano, Darrick Chang, Alexey V. Gorshkov

Abstract: Tightly confined modes of light, as in optical nanofibers or photonic crystal waveguides, can lead to large optical coupling in atomic systems, which mediates long-range interactions between atoms. These one-dimensional systems can naturally possess couplings that are asymmetric between modes propagating in different directions. Strong long-range interaction among atoms via these modes can drive t… ▽ More Tightly confined modes of light, as in optical nanofibers or photonic crystal waveguides, can lead to large optical coupling in atomic systems, which mediates long-range interactions between atoms. These one-dimensional systems can naturally possess couplings that are asymmetric between modes propagating in different directions. Strong long-range interaction among atoms via these modes can drive them to a self-organized periodic distribution. In this paper, we examine the self-organizing behavior of atoms in one dimension coupled to a chiral reservoir. We determine the solution to the equations of motion in different parameter regimes, relative to both the detuning of the pump laser that initializes the atomic dipole-dipole interactions and the degree of reservoir chirality. In addition, we calculate possible experimental signatures such as reflectivity from self-organized atoms and motional sidebands. △ Less

Submitted 7 December, 2016; v1 submitted 20 May, 2016; originally announced May 2016.

Comments: 14 pages, 12 figures

Journal ref: Phys. Rev. A 94, 053855 (2016)

Photon-correlation measurements of atomic-cloud temperature using an optical nanofiber

Authors: J. A. Grover, P. Solano, L. A. Orozco, S. L. Rolston

Abstract: We develop a temperature measurement of an atomic cloud based on the temporal correlations of fluorescence photons evanescently coupled into an optical nanofiber. We measure the temporal width of the intensity-intensity correlation function due to atomic transit time and use it to determine the most probable atomic velocity, hence the temperature. This technique agrees well with standard time-of-f… ▽ More We develop a temperature measurement of an atomic cloud based on the temporal correlations of fluorescence photons evanescently coupled into an optical nanofiber. We measure the temporal width of the intensity-intensity correlation function due to atomic transit time and use it to determine the most probable atomic velocity, hence the temperature. This technique agrees well with standard time-of-flight temperature measurements. We confirm our results with trajectory simulations. △ Less

Submitted 13 July, 2015; originally announced July 2015.

Comments: 7 pages, 5 figures; accepted to PRA

Journal ref: Phys. Rev. A 92, 013850 (2015)

Ultrahigh Transmission Optical Nanofibers

Authors: J. E. Hoffman, S. Ravets, J. A. Grover, P. Solano, P. R. Kordell, J. D. Wong-Campos, L. A. Orozco, S. L. Rolston

Abstract: We present a procedure for reproducibly fabricating ultrahigh transmission optical nanofibers (530 nm diameter and 84 mm stretch) with single-mode transmissions of 99.95 $ \pm$ 0.02%, which represents a loss from tapering of 2.6 $\,\times \,$ 10$^{-5}$ dB/mm when normalized to the entire stretch. When controllably launching the next family of higher-order modes on a fiber with 195 mm stretch, we a… ▽ More We present a procedure for reproducibly fabricating ultrahigh transmission optical nanofibers (530 nm diameter and 84 mm stretch) with single-mode transmissions of 99.95 $ \pm$ 0.02%, which represents a loss from tapering of 2.6 $\,\times \,$ 10$^{-5}$ dB/mm when normalized to the entire stretch. When controllably launching the next family of higher-order modes on a fiber with 195 mm stretch, we achieve a transmission of 97.8 $\pm$ 2.8%, which has a loss from tapering of 5.0 $\,\times \,$ 10$^{-4}$ dB/mm when normalized to the entire stretch. Our pulling and transfer procedures allow us to fabricate optical nanofibers that transmit more than 400 mW in high vacuum conditions. These results, published as parameters in our previous work, present an improvement of two orders of magnitude less loss for the fundamental mode and an increase in transmission of more than 300% for higher-order modes, when following the protocols detailed in this paper. We extract from the transmission during the pull, the only reported spectrogram of a fundamental mode launch that does not include excitation to asymmetric modes; in stark contrast to a pull in which our cleaning protocol is not followed. These results depend critically on the pre-pull cleanliness and when properly following our pulling protocols are in excellent agreement with simulations. △ Less

Submitted 13 May, 2014; originally announced May 2014.

Comments: 32 pages, 10 figures, accepted to AIP Advances

Journal ref: AIP Advances 4, 067124 (2014)