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Indirect measurement of atomic magneto-optical rotation via Hilbert transform (2024)
Journal Article
Briscoe, J. D., Pizzey, D., Wrathmall, S. A., & Hughes, I. G. (2024). Indirect measurement of atomic magneto-optical rotation via Hilbert transform. Journal of Physics B: Atomic, Molecular and Optical Physics, 57(17), 175401. https://doi.org/10.1088/1361-6455/ad5e24

The Kramers–Kronig relations are a pivotal foundation of linear optics and atomic physics, embedding a physical connection between the real and imaginary components of any causal response function. A mathematically equivalent, but simpler, approach i... Read More about Indirect measurement of atomic magneto-optical rotation via Hilbert transform.

A device for magnetic-field angle control in magneto-optical filters using a solenoid-permanent magnet pair. (2024)
Journal Article
Alqarni, S. A., Briscoe, J. D., Higgins, C. R., Logue, F. D., Pizzey, D., Robertson-Brown, T. G., & Hughes, I. G. (2024). A device for magnetic-field angle control in magneto-optical filters using a solenoid-permanent magnet pair. Review of Scientific Instruments, 95(3), Article 035103. https://doi.org/10.1063/5.0174264

Atomic bandpass filters are used in a variety of applications due to their narrow bandwidths and high transmission at specific frequencies. Predominantly, these filters are in the Faraday (Voigt) geometry, using an applied axial (transverse) magnetic... Read More about A device for magnetic-field angle control in magneto-optical filters using a solenoid-permanent magnet pair..

Voigt transmission windows in optically thick atomic vapours: a method to create single-peaked line centre filters (2023)
Journal Article
Briscoe, J. D., Logue, F. D., Pizzey, D., Wrathmall, S. A., & Hughes, I. G. (2023). Voigt transmission windows in optically thick atomic vapours: a method to create single-peaked line centre filters. Journal of Physics B: Atomic, Molecular and Optical Physics, 56(10), Article 105403. https://doi.org/10.1088/1361-6455/acc49c

Cascading light through two thermal vapour cells has been shown to improve the performance of atomic filters that aim to maximise peak transmission over a minimised bandpass window. In this paper, we explore the atomic physics responsible for the ope... Read More about Voigt transmission windows in optically thick atomic vapours: a method to create single-peaked line centre filters.

Laser spectroscopy of hot atomic vapours: from ’scope to theoretical fit (2022)
Journal Article
Pizzey, D., Briscoe, J. D., Logue, F. D., Ponciano-Ojeda, F. S., Wrathmall, S. A., & Hughes, I. G. (2022). Laser spectroscopy of hot atomic vapours: from ’scope to theoretical fit. New Journal of Physics, 24, https://doi.org/10.1088/1367-2630/ac9cfe

The spectroscopy of hot atomic vapours is a hot topic. Many of the work-horse techniques of contemporary atomic physics were first demonstrated in hot vapours. Alkali-metal atomic vapours are ideal media for quantum-optics experiments as they combine... Read More about Laser spectroscopy of hot atomic vapours: from ’scope to theoretical fit.

Better magneto-optical filters with cascaded vapor cells (2022)
Journal Article
Logue, F. D., Briscoe, J. D., Pizzey, D., Wrathmall, S. A., & Hughes, I. G. (2022). Better magneto-optical filters with cascaded vapor cells. Optics Letters, 47(12), 2975-2978. https://doi.org/10.1364/ol.459291

Single-cell magneto-optical Faraday filters find great utility and are realized with either ‘wing’ or ‘line center’ spectral profiles. We show that cascading a second cell with independent axial (Faraday) or transverse (Voigt) magnetic field leads to... Read More about Better magneto-optical filters with cascaded vapor cells.

The Solar Activity Monitor Network – SAMNet (2022)
Journal Article
Erdélyi, R., Korsós, M. B., Huang, X., Yang, Y., Pizzey, D., Wrathmall, S. A., …Zuccarello, F. (2022). The Solar Activity Monitor Network – SAMNet. Journal of Space Weather and Space Climate, 12, Article 2. https://doi.org/10.1051/swsc/2021025

The Solar Activity Magnetic Monitor (SAMM) Network (SAMNet) is a future UK-led international network of ground-based solar telescope stations. SAMNet, at its full capacity, will continuously monitor the Sun’s intensity, magnetic, and Doppler velocity... Read More about The Solar Activity Monitor Network – SAMNet.

Using residual heat maps to visualise Benford’s multi-digit law (2021)
Journal Article
Hull, B., Long, A., & Hughes, I. G. (2022). Using residual heat maps to visualise Benford’s multi-digit law. European Journal of Physics, 43(1), Article 015803. https://doi.org/10.1088/1361-6404/ac3671

It has been known for more than a century that, counter to one's intuition, the frequency of occurrence of the first significant digit in a very large number of numerical data sets is nonuniformly distributed. This result is encapsulated in Benford's... Read More about Using residual heat maps to visualise Benford’s multi-digit law.

White-light versus discrete wavelength measurements of Faraday dispersion and the Verdet constant (2021)
Journal Article
Maxwell, J. L., Hughes, I. G., & Adams, C. S. (2022). White-light versus discrete wavelength measurements of Faraday dispersion and the Verdet constant. European Journal of Physics, 43(1), Article 015302. https://doi.org/10.1088/1361-6404/ac31d3

The wavelength dependence of the Faraday effect may be measured either sequentially at particular wavelengths using narrow band sources, or simultaneously at many wavelengths using a white-light or broadband source. We apply both methods to measure t... Read More about White-light versus discrete wavelength measurements of Faraday dispersion and the Verdet constant.

Electromagnetically induced transparency in a V-system with 87Rb vapor in the hyperfine Paschen–Back regime (2021)
Journal Article
Higgins, C. R., & Hughes, I. G. (2021). Electromagnetically induced transparency in a V-system with 87Rb vapor in the hyperfine Paschen–Back regime. Optics Letters, 54(16), Article 165403. https://doi.org/10.1088/1361-6455/ac20be

We observe electromagnetically induced transparency (EIT) in a V-system in a thermal rubidium-87 vapour in the hyperfine Paschen-Back regime, realised with a 0.6 T axial magnetic field. In this regime energy levels are no longer degenerate and EIT fe... Read More about Electromagnetically induced transparency in a V-system with 87Rb vapor in the hyperfine Paschen–Back regime.

The Raspberry Pi auto-aligner: Machine learning for automated alignment of laser beams (2021)
Journal Article
Mathew, R. S., O’Donnell, R., Pizzey, D., & Hughes, I. G. (2021). The Raspberry Pi auto-aligner: Machine learning for automated alignment of laser beams. Review of Scientific Instruments, 92(1), Article 015117. https://doi.org/10.1063/5.0032588

We present a novel solution to automated beam alignment optimization. This device is based on a Raspberry Pi computer, stepper motors, commercial optomechanics and electronic devices, and the open-source machine learning algorithm M-LOOP. We provide... Read More about The Raspberry Pi auto-aligner: Machine learning for automated alignment of laser beams.

Absorption spectroscopy and Stokes polarimetry in a 87Rb vapour in the Voigt geometry with a 1.5 T external magnetic field (2020)
Journal Article
Ponciano-Ojeda, F. S., Logue, F. D., & Hughes, I. G. (2021). Absorption spectroscopy and Stokes polarimetry in a 87Rb vapour in the Voigt geometry with a 1.5 T external magnetic field. Journal of Physics B: Atomic, Molecular and Optical Physics, 54(1), Article 015401. https://doi.org/10.1088/1361-6455/abc7ff

This paper provides details of a spectroscopic investigation of a thermal 87Rb atomic vapour. The experiment was conducted with an external magnetic field of 1.5 T in the Voigt geometry. Very good quantitative agreement between experimental data and... Read More about Absorption spectroscopy and Stokes polarimetry in a 87Rb vapour in the Voigt geometry with a 1.5 T external magnetic field.

Nanostructured alkali-metal vapor cells (2020)
Journal Article
Cutler, T., Hamlyn, W., Renger, J., Whittaker, K., Pizzey, D., Hughes, I., …Adams, C. (2020). Nanostructured alkali-metal vapor cells. Physical Review Applied, 14(3), Article 034054. https://doi.org/10.1103/physrevapplied.14.034054

Atom-light interactions in micro- and nanoscale systems hold great promise for alternative technologies based on integrated emitters and optical modes. We present the design architecture, construction method, and characterization of an all-glass alka... Read More about Nanostructured alkali-metal vapor cells.

Atomic line vs. lens cavity filters: A comparison of their merits (2020)
Journal Article
Higgins, C. R., Pizzey, D., Mathew, R. S., & Hughes, I. G. (2020). Atomic line vs. lens cavity filters: A comparison of their merits. OSA continuum, 3(4), 961-970. https://doi.org/10.1364/osac.390604

We present a comparison between lens cavity filters and atomic line filters, discussing their relative merits for applications in quantum optics. We describe the design, characterization, and stabilization procedure of a lens cavity filter, which con... Read More about Atomic line vs. lens cavity filters: A comparison of their merits.

Optical rotation of white light (2020)
Journal Article
Anderson, J., Gillen, C., Wright, J., Adams, C. S., & Hughes, I. G. (2020). Optical rotation of white light. American Journal of Physics, 88(3), https://doi.org/10.1119/10.0000390

Plane-polarized monochromatic light is rotated in an optically active medium. The extent of the rotation is wavelength dependent, following an optical rotatory dispersion (ORD) curve. Typically, this phenomenon is studied by using a few discrete wave... Read More about Optical rotation of white light.

Measuring the Faraday effect in olive oil using permanent magnets and Malus' law (2020)
Journal Article
Carr, D. L., Spong, N. L., Hughes, I. G., & Adams, C. S. (2020). Measuring the Faraday effect in olive oil using permanent magnets and Malus' law. European Journal of Physics, 41(2), Article 025301. https://doi.org/10.1088/1361-6404/ab50dd

We present a simple permanent magnet set-up that can be used to measure the Faraday effect in gases, liquids and solids. By fitting the transmission curve as a function of polarizer angle (Malus' law) we average over short-term fluctuations in the la... Read More about Measuring the Faraday effect in olive oil using permanent magnets and Malus' law.

Lattice-depth measurement using continuous grating atom diffraction (2019)
Journal Article
Beswick, B. T., Hughes, I. G., & Gardiner, S. A. (2019). Lattice-depth measurement using continuous grating atom diffraction. Physical Review A, 100(6), Article 063629. https://doi.org/10.1103/physreva.100.063629

We propose an approach to characterizing the depths of optical lattices, in which either an atomic gas is given a finite initial momentum or, alternatively, a corresponding “walking” configuration is applied to the optical lattice itself. This leads... Read More about Lattice-depth measurement using continuous grating atom diffraction.

Measurement of the atom-surface van der Waals interaction by transmission spectroscopy in a wedged nanocell (2019)
Journal Article
Peyrot, T., Šibalić, N., Sortais, Y., Browaeys, A., Sargsyan, A., Sarkisyan, D., …Adams, C. (2019). Measurement of the atom-surface van der Waals interaction by transmission spectroscopy in a wedged nanocell. Physical Review A, 100(2), Article 022503. https://doi.org/10.1103/physreva.100.022503

We demonstrate a method for measuring atom-surface interactions using transmission spectroscopy of thermal vapors confined in a wedged nanocell. The wedged shape of the cell allows complementary measurements of both the bulk atomic vapor and atoms cl... Read More about Measurement of the atom-surface van der Waals interaction by transmission spectroscopy in a wedged nanocell.

Optical Transmission of an Atomic Vapor in the Mesoscopic Regime (2019)
Journal Article
Peyrot, T., Sortais, Y., Greffet, J., Browaeys, A., Sargsyan, A., Keaveney, J., …Adams, C. (2019). Optical Transmission of an Atomic Vapor in the Mesoscopic Regime. Physical Review Letters, 122(11), Article 113401. https://doi.org/10.1103/physrevlett.122.113401

By measuring the transmission of near-resonant light through an atomic vapor confined in a nanocell we demonstrate a mesoscopic optical response arising from the nonlocality induced by the motion of atoms with a phase coherence length larger than the... Read More about Optical Transmission of an Atomic Vapor in the Mesoscopic Regime.

Quantitative optical spectroscopy of $^{87}$Rb vapour in the Voigt geometry in DC magnetic fields up to 0.4T (2019)
Journal Article
Keaveney, J., Ponciano-Ojeda, F. S., Rieche, S. M., Raine, M. J., Hampshire, D. P., & Hughes, I. G. (2019). Quantitative optical spectroscopy of $^{87}$Rb vapour in the Voigt geometry in DC magnetic fields up to 0.4T. Journal of Physics B: Atomic, Molecular and Optical Physics, 52(5), Article 055003. https://doi.org/10.1088/1361-6455/ab0186

We present a detailed spectroscopic investigation of a thermal ⁸⁷Rb atomic vapour in magnetic fields up to 0.4T in the Voigt geometry. We fit experimental spectra with our theoretical model ElecSus and find excellent quantitative agreement, with RMS... Read More about Quantitative optical spectroscopy of $^{87}$Rb vapour in the Voigt geometry in DC magnetic fields up to 0.4T.

An intuitive approach to structuring the three electric field components of light (2019)
Journal Article
Maucher, F., Skupin, S., Gardiner, S., & Hughes, I. (2019). An intuitive approach to structuring the three electric field components of light. New Journal of Physics, 21, Article 013032. https://doi.org/10.1088/1367-2630/aaf711

This paper presents intuitive interpretations of tightly focused beams of light by drawing analogies with two-dimensional electrostatics, magnetostatics and fluid dynamics. We use a Helmholtz decomposition of the transverse electric field components... Read More about An intuitive approach to structuring the three electric field components of light.

Lattice-depth measurement using multipulse atom diffraction in and beyond the weakly diffracting limit (2019)
Journal Article
Beswick, B. T., Hughes, I. G., & Gardiner, S. A. (2019). Lattice-depth measurement using multipulse atom diffraction in and beyond the weakly diffracting limit. Physical Review A, 99(1), Article 013614. https://doi.org/10.1103/physreva.99.013614

Precise knowledge of optical lattice depths is important for a number of areas of atomic physics, most notably in quantum simulation, atom interferometry, and for the accurate determination of transition matrix elements. In such experiments, lattice... Read More about Lattice-depth measurement using multipulse atom diffraction in and beyond the weakly diffracting limit.

Optics f2f (2018)
Book
Adams, C., & Hughes, I. (in press). Optics f2f. OUP

Optimized ultra-narrow atomic bandpass filters via magneto-optic rotation in an unconstrained geometry (2018)
Journal Article
Keaveney, J., Wrathmall, S. A., Adams, C. S., & Hughes, I. G. (2018). Optimized ultra-narrow atomic bandpass filters via magneto-optic rotation in an unconstrained geometry. Optics Letters, 43(17), 4272-4275. https://doi.org/10.1364/ol.43.004272

Atomic bandpass filters are widely used in a variety of applications, owing to their high peak transmission and narrow bandwidths. Much of the previous literature has used the Faraday effect to realize these filters, where an axial magnetic field is... Read More about Optimized ultra-narrow atomic bandpass filters via magneto-optic rotation in an unconstrained geometry.

Simultaneous two-photon resonant optical laser locking (STROLLing) in the hyperfine Paschen-Back regime (2018)
Journal Article
Mathew, R. S., Ponciano-Ojeda, F., Keaveney, J., Whiting, D., & Hughes, I. (2018). Simultaneous two-photon resonant optical laser locking (STROLLing) in the hyperfine Paschen-Back regime. Optics Letters, 43(17), 4204-4207. https://doi.org/10.1364/ol.43.004204

We demonstrate a technique to lock simultaneously two laser frequencies to each step of a two-photon transition in the presence of a magnetic field sufficiently large to gain access to the hyperfine Paschen–Back regime. A ladder configuration with th... Read More about Simultaneous two-photon resonant optical laser locking (STROLLing) in the hyperfine Paschen-Back regime.

Collective Lamb shift of a nanoscale atomic vapor layer within a sapphire cavity (2018)
Journal Article
Peyrot, T., Keaveney, J., Sortais, Y. R., Sargsyan, A., Sarkisyan, D., Hughes, I. G., …Adams, C. S. (2018). Collective Lamb shift of a nanoscale atomic vapor layer within a sapphire cavity. Physical Review Letters, 120(24), Article 243401. https://doi.org/10.1103/physrevlett.120.243401

We measure the near-resonant transmission of light through a dense medium of potassium vapor confined in a cell with nanometer thickness in order to investigate the origin and validity of the collective Lamb shift. A complete model including the mult... Read More about Collective Lamb shift of a nanoscale atomic vapor layer within a sapphire cavity.

Creating Complex Optical Longitudinal Polarization Structures (2018)
Journal Article
Maucher, F., Skupin, S., Gardiner, S., & Hughes, I. (2018). Creating Complex Optical Longitudinal Polarization Structures. Physical Review Letters, 120(16), Article 163903. https://doi.org/10.1103/physrevlett.120.163903

In this Letter, we show that it is possible to structure the longitudinal polarization component of light. We illustrate our approach by demonstrating linked and knotted longitudinal vortex lines acquired upon nonparaxially propagating a tightly focu... Read More about Creating Complex Optical Longitudinal Polarization Structures.

ElecSus: Extension to arbitrary geometry magneto-optics (2017)
Journal Article
Keaveney, J., Adams, C. S., & Hughes, I. G. (2017). ElecSus: Extension to arbitrary geometry magneto-optics. Computer Physics Communications, 224, 311-324. https://doi.org/10.1016/j.cpc.2017.12.001

We present a major update to ElecSus, a computer program and underlying model to calculate the electric susceptibility of an alkali-metal atomic vapour. Knowledge of the electric susceptibility of a medium is essential to predict its absorptive and d... Read More about ElecSus: Extension to arbitrary geometry magneto-optics.

Four-wave mixing in a non-degenerate four-level diamond configuration in the hyperfine Paschen–Back regime (2017)
Journal Article
Whiting, D. J., Mathew, R. S., Keaveney, J., Adams, C. S., & Hughes, I. G. (2018). Four-wave mixing in a non-degenerate four-level diamond configuration in the hyperfine Paschen–Back regime. Journal of Modern Optics, 65(2), 119-128. https://doi.org/10.1080/09500340.2017.1377308

We present an experimental study of seeded four-wave mixing (4WM) using a diamond excitation scheme (with states from the 5S1/2,5P1/2,5P3/25S1/2,5P1/2,5P3/2 and 5D3/25D3/2 terms) in a thermal vapour of 87Rb87Rb atoms. We investigate the 4WM spectra u... Read More about Four-wave mixing in a non-degenerate four-level diamond configuration in the hyperfine Paschen–Back regime.

Single-photon interference due to motion in an atomic collective excitation (2017)
Journal Article
Whiting, D. J., Šibalić, N., Keaveney, J., Adams, C. S., & Hughes, I. G. (2017). Single-photon interference due to motion in an atomic collective excitation. Physical Review Letters, 118(25), Article 253601. https://doi.org/10.1103/physrevlett.118.253601

We experimentally demonstrate the generation of heralded bi-chromatic single photons from an atomic collective spin excitation (CSE). The photon arrival times display collective quantum beats, a novel interference effect resulting from the relative m... Read More about Single-photon interference due to motion in an atomic collective excitation.

Velocity selection in a Doppler-broadened ensemble of atoms interacting with a monochromatic laser beam (2017)
Journal Article
Hughes, I. G. (2018). Velocity selection in a Doppler-broadened ensemble of atoms interacting with a monochromatic laser beam. Journal of Modern Optics, 65(5-6), 640-647. https://doi.org/10.1080/09500340.2017.1328749

There is extensive use of monochromatic lasers to select atoms with a narrow range of velocities in many atomic physics experiments. For the commonplace situation of the inhomogeneous Doppler-broadened (Gaussian) linewidth exceeding the homogeneous (... Read More about Velocity selection in a Doppler-broadened ensemble of atoms interacting with a monochromatic laser beam.

A visual understanding of optical rotation using corn syrup (2017)
Journal Article
Nixon, M., & Hughes, I. (2017). A visual understanding of optical rotation using corn syrup. European Journal of Physics, 38(4), Article 045302. https://doi.org/10.1088/1361-6404/aa6a0b

In this paper a visual demonstration of optical rotation is presented, with content appropriate for use in a lecture demonstration as well as quantitative techniques suitable for an undergraduate-laboratory experiment. Linearly polarised lasers of va... Read More about A visual understanding of optical rotation using corn syrup.

Selective reflection from an Rb layer with a thickness below λ/12 and applications (2017)
Journal Article
Sargsyan, A., Papoyan, A., Hughes, I. G., Adams, C. S., & Sarkisyan, D. (2017). Selective reflection from an Rb layer with a thickness below λ/12 and applications. Optics Letters, 42(8), 1476-1479. https://doi.org/10.1364/ol.42.001476

We have studied the peculiarities of selective reflection from an Rb vapor cell with a thickness L < 70 nm, which is smaller than the length scale of evanescent fields λ∕2π and more than an order of magnitude smaller than the optical wavelength. A 24... Read More about Selective reflection from an Rb layer with a thickness below λ/12 and applications.

epsilon-pseudoclassical model for quantum resonances in a cold dilute atomic gas periodically driven by finite-duration standing-wave laser pulses (2016)
Journal Article
Beswick, B., Hughes, I., Gardiner, S., Astier, H., Andersen, M., & Daszuta, B. (2016). epsilon-pseudoclassical model for quantum resonances in a cold dilute atomic gas periodically driven by finite-duration standing-wave laser pulses. Physical Review A, 94(6), Article 063604. https://doi.org/10.1103/physreva.94.063604

Atom interferometers are a useful tool for precision measurements of fundamental physical phenomena, ranging from the local gravitational-field strength to the atomic fine-structure constant. In such experiments, it is desirable to implement a high-m... Read More about epsilon-pseudoclassical model for quantum resonances in a cold dilute atomic gas periodically driven by finite-duration standing-wave laser pulses.

A single-mode external cavity diode laser using an intra-cavity atomic Faraday filter with short-term linewidth <400 kHz and long-term stability of <1 MHz (2016)
Journal Article
Keaveney, J., Hamlyn, W. J., Adams, C. S., & Hughes, I. G. (2016). A single-mode external cavity diode laser using an intra-cavity atomic Faraday filter with short-term linewidth

We report on the development of a diode laser system - the “Faraday laser” - using an atomic Faraday filter as the frequency-selective element. In contrast to typical external-cavity diode laser systems which offer tunable output frequency but requir... Read More about A single-mode external cavity diode laser using an intra-cavity atomic Faraday filter with short-term linewidth <400 kHz and long-term stability of <1 MHz.

Excitation of knotted vortex lines in matter waves (2016)
Journal Article
Maucher, F., Gardiner, S., & Hughes, I. (2016). Excitation of knotted vortex lines in matter waves. New Journal of Physics, 18(6), Article 063016. https://doi.org/10.1088/1367-2630/18/6/063016

We study the creation of knotted ultracold matter waves in Bose–Einstein condensates via coherent two-photon Raman transitions with a Λ level configuration. The Raman transition allows an indirect transfer of atoms from the internal state $| a\rangle... Read More about Excitation of knotted vortex lines in matter waves.

Direct measurement of excited-state dipole matrix elements using electromagnetically induced transparency in the hyperfine Paschen-Back regime (2016)
Journal Article
Whiting, D., Keaveney, J., Adams, C., & Hughes, I. (2016). Direct measurement of excited-state dipole matrix elements using electromagnetically induced transparency in the hyperfine Paschen-Back regime. Physical Review A, 93(4), Article 043854. https://doi.org/10.1103/physreva.93.043854

Applying large magnetic fields to gain access to the hyperfine Paschen-Back regime can isolate three-level systems in a hot alkali metal vapors, thereby simplifying usually complex atom-light interactions. We use this method to make the first direct... Read More about Direct measurement of excited-state dipole matrix elements using electromagnetically induced transparency in the hyperfine Paschen-Back regime.

Spectroscopic detection of atom-surface interactions in an atomic-vapor layer with nanoscale thickness (2015)
Journal Article
Whittaker, K., Keaveney, J., Hughes, I., Sargsyan, A., Sarkisyan, D., & Adams, C. (2015). Spectroscopic detection of atom-surface interactions in an atomic-vapor layer with nanoscale thickness. Physical Review A, 92(5), Article 052706. https://doi.org/10.1103/physreva.92.052706

We measure the resonance line shape of atomic-vapor layers with nanoscale thickness confined between two sapphire windows. The measurement is performed by scanning a probe laser through resonance and collecting the scattered light. The line shape is... Read More about Spectroscopic detection of atom-surface interactions in an atomic-vapor layer with nanoscale thickness.

Optimization of atomic Faraday filters in the presence of homogeneous line broadening (2015)
Journal Article
Zentile, M. A., Mathew, R. S., Whiting, D. J., Keaveney, J., Adams, C. S., & Hughes, I. G. (2015). Optimization of atomic Faraday filters in the presence of homogeneous line broadening. Journal of Physics B: Atomic, Molecular and Optical Physics, 48(18), Article 185001. https://doi.org/10.1088/0953-4075/48/18/185001

We show that homogeneous line broadening drastically affects the performance of atomic Faraday filters. We study the effects of cell length and find that the behaviour of 'line-centre' filters are quite different from 'wing-type' filters, where the e... Read More about Optimization of atomic Faraday filters in the presence of homogeneous line broadening.

Electromagnetically induced absorption in a nondegenerate three-level ladder system (2015)
Journal Article
Whiting, D., Bimbard, E., Keaveney, J., Zentile, M., Adams, C., & Hughes, I. (2015). Electromagnetically induced absorption in a nondegenerate three-level ladder system. Optics Letters, 40(18), 4289-4292. https://doi.org/10.1364/ol.40.004289

We investigate, theoretically and experimentally, the transmission of light through a thermal vapor of three-level ladder-type atoms, in the presence of two counterpropagating control fields. A simple theoretical model predicts the presence of electr... Read More about Electromagnetically induced absorption in a nondegenerate three-level ladder system.

Absolute absorption on the potassium D lines: theory and experiment (2015)
Journal Article
Hanley, R. K., Gregory, P. D., Hughes, I. G., & Cornish, S. L. (2015). Absolute absorption on the potassium D lines: theory and experiment. Journal of Physics B: Atomic, Molecular and Optical Physics, 48(19), Article 195004. https://doi.org/10.1088/0953-4075/48/19/195004

We present a detailed study of the absolute Doppler-broadened absorption of a probe beam scanned across the potassium D lines in a thermal vapour. Spectra using a weak probe were measured on the 4S $\to $ 4P transition and compared to the theoretical... Read More about Absolute absorption on the potassium D lines: theory and experiment.

Atomic Faraday filter with equivalent noise bandwidth less than 1  GHz (2015)
Journal Article
Zentile, M., Whiting, D., Keaveney, J., Adams, C., & Hughes, I. (2015). Atomic Faraday filter with equivalent noise bandwidth less than 1  GHz. Optics Letters, 40(9), 2000-2003. https://doi.org/10.1364/ol.40.002000

We demonstrate an atomic bandpass optical filter with an equivalent noise bandwidth less than 1 GHz using the D1 line in a cesium vapor. We use the ElecSus computer program to find optimal experimental parameters and find that, for important quantiti... Read More about Atomic Faraday filter with equivalent noise bandwidth less than 1  GHz.

Hilbert transform: applications to atomic spectra (2015)
Journal Article
Whittaker, K., Keveaney, J., Hughes, I., & Adams, C. (2015). Hilbert transform: applications to atomic spectra. Physical Review A, 91(3), Article 032513. https://doi.org/10.1103/physreva.91.032513

In many areas of physics, the Kramers-Kronig relations are used to extract information about the real part of the optical response of a medium from its imaginary counterpart. In this paper we discuss an alternative but mathematically equivalent appro... Read More about Hilbert transform: applications to atomic spectra.

ElecSus: A program to calculate the electric susceptibility of an atomic ensemble (2014)
Journal Article
Zentile, M., Keaveney, J., Weller, L., Whiting, D., Adams, C., & Hughes, I. (2015). ElecSus: A program to calculate the electric susceptibility of an atomic ensemble. Computer Physics Communications, 189, 162-174. https://doi.org/10.1016/j.cpc.2014.11.023

We present a computer program and underlying model to calculate the electric susceptibility of a gas, which is essential to predict its absorptive and dispersive properties. Our program focuses on alkali-metal vapours where we use a matrix representa... Read More about ElecSus: A program to calculate the electric susceptibility of an atomic ensemble.

Optical Response of Gas-Phase Atoms at Less than λ/80 from a Dielectric Surface (2014)
Journal Article
Whittaker, K., Keaveney, J., Hughes, I., Sargsyan, A., Sarkisyan, D., & Adams, C. (2014). Optical Response of Gas-Phase Atoms at Less than λ/80 from a Dielectric Surface. Physical Review Letters, 112, Article 253201. https://doi.org/10.1103/physrevlett.112.253201

We present experimental observations of atom-light interactions within tens of nanometers (down to 11 nm) of a sapphire surface. Using photon counting we detect the fluorescence from of order one thousand Rb or Cs atoms, confined in a vapor with thic... Read More about Optical Response of Gas-Phase Atoms at Less than λ/80 from a Dielectric Surface.

The hyperfine Paschen-Back Faraday effect (2014)
Journal Article
Zentile, M. A., Andrews, R., Weller, L., Knappe, S., Adams, C. S., & Hughes, I. G. (2014). The hyperfine Paschen-Back Faraday effect. Journal of Physics B: Atomic, Molecular and Optical Physics, 47(7), Article 075005. https://doi.org/10.1088/0953-4075/47/7/075005

We investigate experimentally and theoretically the Faraday effect in an atomic medium in the hyperfine Paschen–Back regime, where the Zeeman interaction is larger than the hyperfine splitting. We use a small permanent magnet and a micro-fabricated v... Read More about The hyperfine Paschen-Back Faraday effect.

Piezoelectrically actuated time-averaged atomic microtraps (2012)
Journal Article
West, A., Wade, C., Weatherill, K., & Hughes, I. (2012). Piezoelectrically actuated time-averaged atomic microtraps. Applied Physics Letters, 101(2), Article 023115. https://doi.org/10.1063/1.4736580

We present a scheme for creating tight and adiabatic time-averaged atom-traps through the piezoelectric actuation of nanomagnetic structures. We show that potentials formed by the circular translation of magnetic structures have several advantages ov... Read More about Piezoelectrically actuated time-averaged atomic microtraps.

Optical preparation and measurement of atomic coherence at gigahertz bandwidth (2012)
Journal Article
Siddons, P., Adams, C., & Hughes, I. (2012). Optical preparation and measurement of atomic coherence at gigahertz bandwidth. Journal of Physics B: Atomic, Molecular and Optical Physics, 45(12), https://doi.org/10.1088/0953-4075/45/12/124009

We detail a method for the preparation of atomic coherence in a high-density atomic vapour of 87Rb, utilizing a coherent preparation scheme of off-resonant gigahertz bandwidth pulses. The scheme is found to be faster and more effective than technique... Read More about Optical preparation and measurement of atomic coherence at gigahertz bandwidth.

Measuring the Stokes parameters for light transmitted by a high-density rubidium vapour in large magnetic fields (2012)
Journal Article
Weller, L., Dalton, T., Siddons, P., Adams, C., & Hughes, I. (2012). Measuring the Stokes parameters for light transmitted by a high-density rubidium vapour in large magnetic fields. Journal of Physics B: Atomic, Molecular and Optical Physics, 45(5), Article 055001. https://doi.org/10.1088/0953-4075/45/5/055001

Here we report on measurements of the absolute absorption and dispersion of light in a dense rubidium vapour on the D2 line in the weak-probe regime with an applied magnetic field. A model for the electric susceptibility of the vapour is presented wh... Read More about Measuring the Stokes parameters for light transmitted by a high-density rubidium vapour in large magnetic fields.

A simple model for calculating magnetic nanowire domain wall fringing fields (2012)
Journal Article
West, A., Hayward, T., Weatherill, K., Schrefl, T., Allwood, D., & Hughes, I. (2012). A simple model for calculating magnetic nanowire domain wall fringing fields. Journal of Physics D: Applied Physics, 45(9), Article 095002. https://doi.org/10.1088/0022-3727/45/9/095002

We present a new approach to calculating magnetic fringing fields from head-to-head type domain walls (DWs) in planar magnetic nanowires. In contrast to calculations based on micromagnetically simulated structures the descriptions of the fields are f... Read More about A simple model for calculating magnetic nanowire domain wall fringing fields.

Nanomagnetic engineering of the properties of domain wall atom traps (2011)
Journal Article
Hayward, T., West, A., Weatherill, K., Schrefl, T., Hughes, I., & Allwood, D. (2011). Nanomagnetic engineering of the properties of domain wall atom traps. Journal of Applied Physics, 110(12), Article 123918. https://doi.org/10.1063/1.3671631

We have used the results of micromagnetic simulations to investigate the effects of nanowire geometry and domain wall magnetization structure on the characteristic parameters of magnetic atom traps formed by domain walls in planar ferromagnetic nanow... Read More about Nanomagnetic engineering of the properties of domain wall atom traps.

Absolute absorption on the rubidium D1 line including resonant dipole–dipole interactions (2011)
Journal Article
Weller, L., Bettles, R., Siddons, P., Adams, C., & Hughes, I. (2011). Absolute absorption on the rubidium D1 line including resonant dipole–dipole interactions. Journal of Physics B: Atomic, Molecular and Optical Physics, 44(19), Article 195006. https://doi.org/10.1088/0953-4075/44/19/195006

Here we report on measurements of the absolute absorption spectra of dense rubidium vapour on the D1 line in the weak-probe regime for temperatures up to 170 °C and number densities up to 3 × 1014 cm−3. In such vapours, modifications to the homogeneo... Read More about Absolute absorption on the rubidium D1 line including resonant dipole–dipole interactions.

An analytical model of off-resonant Faraday rotation in hot alkali metal vapours (2011)
Journal Article
Kemp, S. L., Hughes, I. G., & Cornish, S. L. (2011). An analytical model of off-resonant Faraday rotation in hot alkali metal vapours. Journal of Physics B: Atomic, Molecular and Optical Physics, 44(23), Article 235004. https://doi.org/10.1088/0953-4075/44/23/235004

We report a thorough investigation of the Faraday effect on the 852 nm D2 transition in a hot caesium vapour, culminating in the development of a simple analytical model for off-resonant Faraday rotation. The model, applicable to all hot alkali metal... Read More about An analytical model of off-resonant Faraday rotation in hot alkali metal vapours.

Design and characterization of a field-switchable nanomagnetic atom mirror (2010)
Journal Article
Hayward, T., West, A., Weatherill, K., Curran, P., Fry, P., Fundi, P., …Allwood, D. (2010). Design and characterization of a field-switchable nanomagnetic atom mirror. Journal of Applied Physics, 108(4), https://doi.org/10.1063/1.3466995

We present a design for a switchable nanomagnetic atom mirror formed by an array of 180° domain walls confined within Ni80Fe20 planar nanowires. A simple analytical model is developed which allows the magnetic field produced by the domain wall array... Read More about Design and characterization of a field-switchable nanomagnetic atom mirror.

Modulation-free pump-probe spectroscopy of strontium atoms (2010)
Journal Article
Javaux, C., Hughes, I., Lochead, G., Millen, J., & Jones, M. (2010). Modulation-free pump-probe spectroscopy of strontium atoms. The European Physical Journal D, 57(2), 151-154. https://doi.org/10.1140/epjd/e2010-00029-4

We have performed polarization spectroscopy on the 5s21S0 →5s5p1P1 transition of atomic strontium. The signal is generated by saturation effects, rather than optical pumping, as the ground state is non-degenerate. This technique generated a dispersio... Read More about Modulation-free pump-probe spectroscopy of strontium atoms.

Optical control of Faraday rotation in hot Rb vapor (2010)
Journal Article
Siddons, P., Adams, C., & Hughes, I. (2010). Optical control of Faraday rotation in hot Rb vapor. Physical Review A, 81(4), Article 043838. https://doi.org/10.1103/physreva.81.043838

We demonstrate controlled polarization rotation of an optical field conditional on the presence of a second field. Induced rotations of greater than π/2 rad are seen with a transmission of 95%, corresponding to a ratio of phase shift to absorption of... Read More about Optical control of Faraday rotation in hot Rb vapor.

Off-resonance absorption and dispersion in vapours of hot alkali-metal atoms (2009)
Journal Article
Siddons, P., Adams, C., & Hughes, I. (2009). Off-resonance absorption and dispersion in vapours of hot alkali-metal atoms. Journal of Physics B: Atomic, Molecular and Optical Physics, 42(17), Article 175004. https://doi.org/10.1088/0953-4075/42/17/175004

We study the absorptive and dispersive properties of Doppler-broadened atomic media as a function of detuning. Beginning from the exact lineshape calculated for a two-level atom, a series of approximations to the electric susceptibility are made. The... Read More about Off-resonance absorption and dispersion in vapours of hot alkali-metal atoms.

A gigahertz-bandwidth atomic probe based on the slow-light Faraday effect (2009)
Journal Article
Siddons, P., Bell, N., Cai, Y., Adams, C., & Hughes, I. (2009). A gigahertz-bandwidth atomic probe based on the slow-light Faraday effect. Nature Photonics, 3(4), 225-229. https://doi.org/10.1038/nphoton.2009.27

The ability to probe quantum systems on short timescales is central to the advancement of quantum technology. Here we show that this is possible using an off-resonant dispersive probe. By applying a magnetic field to an atomic vapour the spectra of t... Read More about A gigahertz-bandwidth atomic probe based on the slow-light Faraday effect.

How weak is a weak probe in laser spectroscopy? (2009)
Journal Article
Sherlock, B., & Hughes, I. (2009). How weak is a weak probe in laser spectroscopy?. American Journal of Physics, 77(2), 111-115. https://doi.org/10.1119/1.3013197

Laser spectroscopy experiments are often conducted with a probe that does not significantly alter the medium’s properties. For a two-level atom a clear measure of the strength of a probe beam in terms of the saturation intensity is known. We show tha... Read More about How weak is a weak probe in laser spectroscopy?.

Optimization of sub-Doppler DAVLL on the rubidium D2 line (2008)
Journal Article
Harris, M., Cornish, S., Tripathi, A., & Hughes, I. (2008). Optimization of sub-Doppler DAVLL on the rubidium D2 line. Journal of Physics B: Atomic, Molecular and Optical Physics, 41(8), Article 085401. https://doi.org/10.1088/0953-4075/41/8/085401

We discuss the physics of sub-Doppler DAVLL spectroscopy, which employs a pump beam with an axial magnetic field to induce dichroism in an atomic vapour. The dichroism is measured by a counterpropagating probe beam, while the pump generates sub-Doppl... Read More about Optimization of sub-Doppler DAVLL on the rubidium D2 line.

Absolute absorption on rubidium D lines: comparison between theory and experiment (2008)
Journal Article
Siddons, P., Adams, C., Ge, C., & Hughes, I. (2008). Absolute absorption on rubidium D lines: comparison between theory and experiment. Journal of Physics B: Atomic, Molecular and Optical Physics, 41(15), Article 155004. https://doi.org/10.1088/0953-4075/41/15/155004

We study the Doppler-broadened absorption of a weak monochromatic probe beam in a thermal rubidium vapour cell on D lines. A detailed model of the susceptibility is developed which takes into account the absolute linestrengths of the allowed electric... Read More about Absolute absorption on rubidium D lines: comparison between theory and experiment.

A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium (2007)
Journal Article
McCarron, D. J., Hughes, I. G., Tierney, P., & Cornish, S. L. (2007). A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium. Review of Scientific Instruments, 78(9), Article 093106. https://doi.org/10.1063/1.2785157

The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D2 transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produ... Read More about A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium.

DAVLL lineshapes in atomic rubidium. (2007)
Journal Article
Millett-Sikking, A., Hughes, I. G., Tierney, P., & Cornish, S. L. (2007). DAVLL lineshapes in atomic rubidium. Journal of Physics B: Atomic, Molecular and Optical Physics, 40(1), 187-198. https://doi.org/10.1088/0953-4075/40/1/017

A comprehensive study of the dichroic atomic vapour laser lock (DAVLL) lineshapes for the D2 transitions in atomic rubidium is presented. All four Doppler-broadened transitions (87Rb F = 1 → F ', 87Rb F = 2 → F ', 85Rb F = 2 → F ' and 85Rb F = 3 → F... Read More about DAVLL lineshapes in atomic rubidium..

Transport of launched cold atoms with a laser guide and pulsed magnetic fields (2006)
Journal Article
Pritchard, M. J., Arnold, A. S., Cornish, S. L., Hallwood, D. W., Pleasant, C. V., & Hughes, I. G. (2006). Transport of launched cold atoms with a laser guide and pulsed magnetic fields. New Journal of Physics, 8, Article 309. https://doi.org/10.1088/1367-2630/8/12/309

We propose the novel combination of a laser guide and magnetic lens to transport a cold atomic cloud. We have modelled the loading and guiding of a launched cloud of cold atoms with the optical dipole force. We discuss the optimum strategy for loadin... Read More about Transport of launched cold atoms with a laser guide and pulsed magnetic fields.

Sagnac interferometry in a slow-light medium (2006)
Journal Article
Purves, G., Adams, C., & Hughes, I. (2006). Sagnac interferometry in a slow-light medium. Physical Review A, 74, https://doi.org/10.1103/physreva.74.023805

We use a Sagnac interferometer to measure the dispersive and absorptive properties of room temperature Rubidium vapor on the D2 line at 780.2 nm. We apply a pump beam such that the resulting system exhibits electromagnetically induced transparency. U... Read More about Sagnac interferometry in a slow-light medium.

Mobile atom traps using magnetic nanowires (2006)
Journal Article
Allwood, D., Schrefl, T., Hrkac, G., Hughes, I., & Adams, C. (2006). Mobile atom traps using magnetic nanowires. Applied Physics Letters, 89(1), https://doi.org/10.1063/1.2219397

By solving the Landau-Lifshitz-Gilbert equation using a finite element method we show that an atom trap can be produced above a ferromagnetic nanowire domain wall. Atoms experience trap frequencies of up to a few megahertz, and can be transported by... Read More about Mobile atom traps using magnetic nanowires.

Double-impulse magnetic focusing of launched cold atoms (2006)
Journal Article
Arnold, A., Pritchard, M., Smith, D., & Hughes, I. (2006). Double-impulse magnetic focusing of launched cold atoms. New Journal of Physics, 8, https://doi.org/10.1088/1367-2630/8/4/053

We have theoretically investigated three-dimensional focusing of a launched cloud of cold atoms using a pair of magnetic lens pulses (the alternate-gradient method). Individual lenses focus radially and defocus axially or vice versa. The performance... Read More about Double-impulse magnetic focusing of launched cold atoms.

Single-impulse magnetic focusing of launched cold atoms (2004)
Journal Article
Pritchard, M., Arnold, A., Smith, D., & Hughes, I. (2004). Single-impulse magnetic focusing of launched cold atoms. Journal of Physics B: Atomic, Molecular and Optical Physics, 37(22), 4435-4450. https://doi.org/10.1088/0953-4075/37/22/004

We have theoretically investigated the focusing of a launched cloud of cold atoms. Time-dependent spatially-varying magnetic fields are used to impart impulses leading to a three-dimensional focus of the launched cloud. We discuss possible coil arran... Read More about Single-impulse magnetic focusing of launched cold atoms.

Non-linear Sagnac interferometry for pump-probe dispersion spectroscopy (2003)
Journal Article
Jundt, G., Purves, G., Adams, C., & Hughes, I. (2003). Non-linear Sagnac interferometry for pump-probe dispersion spectroscopy. The European Physical Journal D, 27(3), 273-276. https://doi.org/10.1140/epjd/e2003-00275-5

We explore pump-probe non-linear Sagnac interferometry as a tool to measure the dispersive properties of a medium. We introduce the background theory, and show experimental spectra obtained on the D2 transition with 85Rb and 87Rb. The measured disper... Read More about Non-linear Sagnac interferometry for pump-probe dispersion spectroscopy.

Polarization spectroscopy of a closed atomic transition: applications to laser frequency locking (2002)
Journal Article
Pearman, C., Adams, C., Cox, S., Griffin, P., Smith, D., & Hughes, I. (2002). Polarization spectroscopy of a closed atomic transition: applications to laser frequency locking. Journal of Physics B: Atomic, Molecular and Optical Physics, 35(24), 5141-5151. https://doi.org/10.1088/0953-4075/35/24/315

We study polarization spectroscopy of Rb vapour. A weak probe beam analyses the birefringence induced in a room temperature vapour by a strong counterpropagating circularly polarized pump beam. In contrast to most other work on polarization spectrosc... Read More about Polarization spectroscopy of a closed atomic transition: applications to laser frequency locking.

Hyperfine effects in electromagnetically induced transparency. (2001)
Journal Article
Badger, S., Hughes, I., & Adams, C. (2001). Hyperfine effects in electromagnetically induced transparency. Journal of Physics B: Atomic, Molecular and Optical Physics, 34(22), L749-L756. https://doi.org/10.1088/0953-4075/34/22/107

The role of hyperfine structure in electromagnetically induced transparency (EIT) is investigated by studying the 5S1/2-5P3/2-5D3/2,5/2 cascade system in 85Rb and 87Rb. We show that if the hyperfine splitting Δhfs is larger than the Rabi frequency of... Read More about Hyperfine effects in electromagnetically induced transparency..

Periodic trajectories of cold atoms in a gravitational cavity (2001)
Journal Article
Hughes, I., Darlington, T., & Hinds, E. (2001). Periodic trajectories of cold atoms in a gravitational cavity. Journal of Physics B: Atomic, Molecular and Optical Physics, 34(14), 2869-2880. https://doi.org/10.1088/0953-4075/34/14/308

We study the classical dynamics of an atom bouncing on a concave reflector, which is sometimes called a gravitational cavity. Experiments and simulations have previously shown that atoms released from particular heights exhibit anomalously long stora... Read More about Periodic trajectories of cold atoms in a gravitational cavity.