pau gomez - Academia.edu (original) (raw)
Papers by pau gomez
Optics Express, Dec 14, 2017
Optical trapping of atoms employs high-intensity fields that necessarily alter atomic level struc... more Optical trapping of atoms employs high-intensity fields that necessarily alter atomic level structure. The calculation of light shifts by perturbation theory fails for scenarios that arise, for example, when the trapping light is near an excited-state transition or for polychromatic fields. We show here that non-perturbative methods based on Floquet's theorem elegantly handle such scenarios. We compare our calculation to precision absorption spectroscopy on cold 87 Rb atoms in a bichromatic optical dipole trap at 1560 + 1529 nm. Proximity to excited-state resonances induces highly nonlinear level shifts, providing a strong test of the theory. The good theory-experiment agreement suggests a new method for accurate measurements of excited-state electric-dipole matrix elements and a precision tool for engineering custom atomic level structures.
La gran part dels estudis, dins del marc energètic, se centren en trobar noves fonts d’energia mé... more La gran part dels estudis, dins del marc energètic, se centren en trobar noves fonts d’energia més netes. Molts d’aquests estudis intenten demostrar la viabilitat real d’utilitzar l’hidrogen com una alternativa energètica. Mitjançant un sistema de reacció a microescala a través d’un microreactor, aquest projecte se centra en estudiar diferents proves catalítiques per observar la producció d’hidrogen a partir de dimetil èter (DME), un gas amb gran futur gràcies a la seva facilitat de manipulació i transport. El hidrogen produït, després d’un adequat procés de purificació, podria ser utilitzat en cel·les de combustible per a aplicacions portàtils. En el present treball també estudia l’ús de diferents catalitzadors, basats en coure i zinc o pal·ladi, i la possibilitat d’utilitzar plaques metàl·liques com a suport per els catalitzadors enlloc d’un suport ceràmic, que és el suport més utilitzat en quasi tota l’experimentació actual. Els catalitzadors a utilitzar han de ser impregnats sobre les plaques metàl·liques amb la suficient adherència, de tal manera que no es puguin desprendre amb facilitat i hi hagi una capa homogènia sobre el metall. Les diferents proves catalítiques que s’estudien són les reaccions de reformat amb vapor, reformat autotèrmic i oxidació parcial. Aquestes reaccions són les més estudiades i amb més futur per obtenir hidrogen a partir de DME. Estudiant les tres reaccions es pot observar quina obté més rendiment i és més eficient per a produir hidrogen amb el sistema de reacció utilitzat. Finalment, és necessari l’elecció i posta a punt de la perifèria del reactor, necessària per el correcte funcionament del sistema de reacció. A més a més, és necessari realitzar proves per tal d’escollir les millors condicions de reacció per dur a terme amb èxit les proves catalítiques
TDX (Tesis Doctorals en Xarxa), Jun 15, 2009
Finalment, la tesi estudia els límits teòrics en la precisió dels receptors GNSS. Alguns d'aquest... more Finalment, la tesi estudia els límits teòrics en la precisió dels receptors GNSS. Alguns d'aquests límits teòrics eren ja coneguts, d'altres veuen ara la llum. El límit de Cramér-Rao (Cramér-Rao Bound, CRB) ens prediu la mínima variància que es pot obtenir en estimar un paràmetre mitjançant un estimador no esbiaixat. La tesi recorda el CRB dels paràmetres de sincronisme, resultat ja conegut. Una de les aportacionsés la derivació del CRB de l'estimador de la posició pel cas convencional i seguint la metodologia DPE. Aquests resultats proporcionen una comparativa asimptòtica dels dos procediments pel posicionament de receptors GNSS. Similarment, el CRB de sincronisme pel cas Bayesià (Posterior Cramér-Rao Bound, PCRB) es presenta, com a límit teòric dels filtres Bayesians proposats en la tesi.
Physical Review Letters, Apr 29, 2020
We describe a comagnetometer employing the f = 1 and f = 2 ground state hyperfine manifolds of a ... more We describe a comagnetometer employing the f = 1 and f = 2 ground state hyperfine manifolds of a 87 Rb spinor Bose-Einstein condensate as colocated magnetometers. The hyperfine manifolds feature nearly opposite gyromagnetic ratios and thus the sum of their precession angles is only weakly coupled to external magnetic fields, while being highly sensitive to any effect that rotates both manifolds in the same way. The f = 1 and f = 2 transverse magnetizations and azimuth angles are independently measured by nondestructive Faraday rotation probing, and we demonstrate a 44.0(8) dB common-mode rejection in good agreement with theory. We show how the magnetometer coherence time can be extended to ∼ 1 s, by using spin-dependent interactions to inhibit hyperfine relaxing collisions between f = 2 atoms. The technique could be used in high sensitivity searches for new physics on submillimeter length scales, precision studies of ultracold collision physics, and angle-resolved studies of quantum spin dynamics.
New Journal of Physics, May 2, 2018
We describe a compact, robust and versatile system for studying the macroscopic spin dynamics in ... more We describe a compact, robust and versatile system for studying the macroscopic spin dynamics in a spinor Bose-Einstein condensate. Condensates of Rb 87 are produced by all-optical evaporation in a 1560 nm optical dipole trap, using a non-standard loading sequence that employs an ancillary 1529 nm beam for partial compensation of the strong differential light-shift induced by the dipole trap itself. We use near-resonant Faraday rotation probing to non-destructively track the condensate magnetization, and demonstrate few-Larmor-cycle tracking with no detectable degradation of the spin polarization. In the ferromagnetic F=1 ground state, we observe the spin orientation between atoms in the condensate is preserved, such that they precess all together like one large spin in the presence of a magnetic field. We characterize this dynamics in terms of the single-shot magnetic coherence times 1 and 2 * , and observe them to be of several seconds, limited only by the residence time of the atoms in the trap. At the densities used, this residence is restricted only by one-body losses set by the vacuum conditions.
Revista de la Sociedad Colombiana de Física, 2007
Información del artículo Análisis de estados cuasiligados en junturas NISIN.
Physical review, Sep 10, 2019
arXiv (Cornell University), Apr 16, 2019
Revista de la Sociedad Colombiana de Física, 2005
En este trabajo se estudia la estabilidad de la cuantizacion de los estados de energia ligados re... more En este trabajo se estudia la estabilidad de la cuantizacion de los estados de energia ligados respecto a las fluctuaciones termicas en una juntura superconductor - metal en el estado normal - superconductor (SNS) con una diferencia de fase fija entre los superconductores. Se analiza el efecto de estas fluctuaciones sobre la coherencia de fase en dicha juntura. Esta coherencia se rompe cuando las cuasiparticulas en los estados no ligados son dispersadas debido a las fluctuaciones termicas antes de que estas puedan viajar de un superconductor al otro. Los estados de energia ligados permanecen cuantizados cuando las cuasiparticulas pueden viajar de un superconductor al otro y regresar al primero antes de ser dispersadas por efecto de las fluctuaciones. Dado que la coherencia de fase esta relacionada con los estados no ligados se muestra que su ruptura, debida a dichas fluctuaciones, no implica necesariamente la destruccion de la cuantizacion de los estados ligados.
Search &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Rescue satellite-based systems, ... more Search &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Rescue satellite-based systems, like COSPAS-SARSAT, are based in Time Of Arrival (TOA) and Frequency Of Arrival (FOA) techniques of the distress beacon signals relied by a set of satellites to calculate the emitter position. In this paper, we propose several algorithms to estimate time delays, Doppler shifts and message demodulation of such signals. Using the system specifications, it
arXiv (Cornell University), Feb 9, 2017
We present a non-perturbative numerical technique for calculating strong light shifts in atoms un... more We present a non-perturbative numerical technique for calculating strong light shifts in atoms under the influence of multiple optical fields with arbitrary polarization. We confirm our technique experimentally by performing spectroscopy of a cloud of cold 87 Rb atoms subjected to ∼ kW/cm 2 intensities of light at 1560.492 nm simultaneous with 1529.269 nm or 1529.282 nm. In these conditions the excited state resonances at 1529.26 nm and 1529.36 nm induce strong level mixing and the shifts are highly nonlinear. By absorption spectroscopy, we observe that the induced shifts of the 5P3/2 hyperfine Zeeman sublevels agree well with our theoretical predictions.. We propose the application of our theory and experiment to accurate measurements of excited-state electric-dipole matrix elements.
Proceedings of the National Academy of Sciences of the United States of America, Feb 7, 2022
We present a magnetic sensor with energy resolution per bandwidth ER <h. We show how a 87 Rb sing... more We present a magnetic sensor with energy resolution per bandwidth ER <h. We show how a 87 Rb single domain spinor Bose-Einstein condensate, detected by non-destructive Faraday-rotation probing, achieves single shot dc magnetic sensitivity of 49(11) fT/ √ Hz in a volume V = 1091(30) µm 3 , and thus ER = 0.070(16)h. We measure experimentally the condensate volume, spin coherence time, and readout noise, and use phase-space methods, backed by 3+1D mean-field simulations, to compute the spin noise. Contributions to the spin noise include one-body and three-body losses and shearing of the projection noise distribution, due to competition of ferromagnetic contact interactions and quadratic Zeeman shifts. Nonetheless, the fully-coherent nature of the single-domain, ultracold two-body interactions allows the system to escape the coherence vs. density trade-off that imposes an energy resolution limit on traditional spin-precession sensors. We predict that other Bose-condensed alkalis, especially the antiferromagnetic 23 Na, can further improve the energy resolution of this method.
We present precision measurements of the f=1 to f=2 inter-hyperfine scattering lengths in a singl... more We present precision measurements of the f=1 to f=2 inter-hyperfine scattering lengths in a single-domain ^87Rb spinor Bose-Einstein condensate. The inter-hyperfine interaction leads to a strong and state-dependent modification of the spin-mixing dynamics with respect to a non-interacting description. We employ hyperfine-specific Faraday-rotation probing to reveal the evolution of the transverse magnetization in each hyperfine manifold for different state preparations, and a co-magnetometer strategy to cancel laboratory magnetic noise. We find the scattering length ratios a_32^(12)/a_20^(1)=-1.27(15) and a_12^(12)/a_20^(1)=-1.31(13), limited by atom number fluctuations. Using better control of atom number, we estimate precisions of ∼ 0.3% should be possible with this technique.
Physical Review Letters, 2020
We describe a comagnetometer employing the f = 1 and f = 2 ground state hyperfine manifolds of a ... more We describe a comagnetometer employing the f = 1 and f = 2 ground state hyperfine manifolds of a 87 Rb spinor Bose-Einstein condensate as colocated magnetometers. The hyperfine manifolds feature nearly opposite gyromagnetic ratios and thus the sum of their precession angles is only weakly coupled to external magnetic fields, while being highly sensitive to any effect that rotates both manifolds in the same way. The f = 1 and f = 2 transverse magnetizations and azimuth angles are independently measured by nondestructive Faraday rotation probing, and we demonstrate a 44.0(8) dB common-mode rejection in good agreement with theory. We show how the magnetometer coherence time can be extended to ∼ 1 s, by using spin-dependent interactions to inhibit hyperfine relaxing collisions between f = 2 atoms. The technique could be used in high sensitivity searches for new physics on submillimeter length scales, precision studies of ultracold collision physics, and angle-resolved studies of quantum spin dynamics.
Bulletin of the American Physical Society, 2017
arXiv: Atomic Physics, 2017
We present a non-perturbative numerical technique for calculating strong light shifts in atoms un... more We present a non-perturbative numerical technique for calculating strong light shifts in atoms under the influence of multiple optical fields with arbitrary polarization. We confirm our technique experimentally by performing spectroscopy of a cloud of cold 87^{87}87Rb atoms subjected to sim\simsim kW/cm$^2$ intensities of light at 1560.492 nm simultaneous with 1529.269 nm or 1529.282 nm. In these conditions the excited state resonances at 1529.26 nm and 1529.36 nm induce strong level mixing and the shifts are highly nonlinear. By absorption spectroscopy, we observe that the induced shifts of the 5P3/2 hyperfine Zeeman sublevels agree well with our theoretical predictions.. We propose the application of our theory and experiment to accurate measurements of excited-state electric-dipole matrix elements.
Optics Express, 2021
We propose and demonstrate cavity-enhanced polarization-rotation measurement as a means to detect... more We propose and demonstrate cavity-enhanced polarization-rotation measurement as a means to detect magnetic effects in transparent media with greater sensitivity at equal optical disturbance to the medium. Using the Jones calculus, we compute the effective polarization rotation effect in a Fabry-Perot cavity containing a magnetic medium, including losses due to enclosure windows or other sources. The results show that when measuring polarization rotation, collecting the transmitted light has advantages in simplicity and linearity relative to collecting the reflected light. We demonstrate the technique by measuring Faraday rotation in a 87 Rb atomic ensemble in the single-pass and cavity-enhanced geometries, and observe enhancement in good agreement with the theoretical predictions. We also demonstrate shot-noise-limited operation of the enhanced rotation scheme in the small-angle regime.
Optics Express, Dec 14, 2017
Optical trapping of atoms employs high-intensity fields that necessarily alter atomic level struc... more Optical trapping of atoms employs high-intensity fields that necessarily alter atomic level structure. The calculation of light shifts by perturbation theory fails for scenarios that arise, for example, when the trapping light is near an excited-state transition or for polychromatic fields. We show here that non-perturbative methods based on Floquet's theorem elegantly handle such scenarios. We compare our calculation to precision absorption spectroscopy on cold 87 Rb atoms in a bichromatic optical dipole trap at 1560 + 1529 nm. Proximity to excited-state resonances induces highly nonlinear level shifts, providing a strong test of the theory. The good theory-experiment agreement suggests a new method for accurate measurements of excited-state electric-dipole matrix elements and a precision tool for engineering custom atomic level structures.
La gran part dels estudis, dins del marc energètic, se centren en trobar noves fonts d’energia mé... more La gran part dels estudis, dins del marc energètic, se centren en trobar noves fonts d’energia més netes. Molts d’aquests estudis intenten demostrar la viabilitat real d’utilitzar l’hidrogen com una alternativa energètica. Mitjançant un sistema de reacció a microescala a través d’un microreactor, aquest projecte se centra en estudiar diferents proves catalítiques per observar la producció d’hidrogen a partir de dimetil èter (DME), un gas amb gran futur gràcies a la seva facilitat de manipulació i transport. El hidrogen produït, després d’un adequat procés de purificació, podria ser utilitzat en cel·les de combustible per a aplicacions portàtils. En el present treball també estudia l’ús de diferents catalitzadors, basats en coure i zinc o pal·ladi, i la possibilitat d’utilitzar plaques metàl·liques com a suport per els catalitzadors enlloc d’un suport ceràmic, que és el suport més utilitzat en quasi tota l’experimentació actual. Els catalitzadors a utilitzar han de ser impregnats sobre les plaques metàl·liques amb la suficient adherència, de tal manera que no es puguin desprendre amb facilitat i hi hagi una capa homogènia sobre el metall. Les diferents proves catalítiques que s’estudien són les reaccions de reformat amb vapor, reformat autotèrmic i oxidació parcial. Aquestes reaccions són les més estudiades i amb més futur per obtenir hidrogen a partir de DME. Estudiant les tres reaccions es pot observar quina obté més rendiment i és més eficient per a produir hidrogen amb el sistema de reacció utilitzat. Finalment, és necessari l’elecció i posta a punt de la perifèria del reactor, necessària per el correcte funcionament del sistema de reacció. A més a més, és necessari realitzar proves per tal d’escollir les millors condicions de reacció per dur a terme amb èxit les proves catalítiques
TDX (Tesis Doctorals en Xarxa), Jun 15, 2009
Finalment, la tesi estudia els límits teòrics en la precisió dels receptors GNSS. Alguns d'aquest... more Finalment, la tesi estudia els límits teòrics en la precisió dels receptors GNSS. Alguns d'aquests límits teòrics eren ja coneguts, d'altres veuen ara la llum. El límit de Cramér-Rao (Cramér-Rao Bound, CRB) ens prediu la mínima variància que es pot obtenir en estimar un paràmetre mitjançant un estimador no esbiaixat. La tesi recorda el CRB dels paràmetres de sincronisme, resultat ja conegut. Una de les aportacionsés la derivació del CRB de l'estimador de la posició pel cas convencional i seguint la metodologia DPE. Aquests resultats proporcionen una comparativa asimptòtica dels dos procediments pel posicionament de receptors GNSS. Similarment, el CRB de sincronisme pel cas Bayesià (Posterior Cramér-Rao Bound, PCRB) es presenta, com a límit teòric dels filtres Bayesians proposats en la tesi.
Physical Review Letters, Apr 29, 2020
We describe a comagnetometer employing the f = 1 and f = 2 ground state hyperfine manifolds of a ... more We describe a comagnetometer employing the f = 1 and f = 2 ground state hyperfine manifolds of a 87 Rb spinor Bose-Einstein condensate as colocated magnetometers. The hyperfine manifolds feature nearly opposite gyromagnetic ratios and thus the sum of their precession angles is only weakly coupled to external magnetic fields, while being highly sensitive to any effect that rotates both manifolds in the same way. The f = 1 and f = 2 transverse magnetizations and azimuth angles are independently measured by nondestructive Faraday rotation probing, and we demonstrate a 44.0(8) dB common-mode rejection in good agreement with theory. We show how the magnetometer coherence time can be extended to ∼ 1 s, by using spin-dependent interactions to inhibit hyperfine relaxing collisions between f = 2 atoms. The technique could be used in high sensitivity searches for new physics on submillimeter length scales, precision studies of ultracold collision physics, and angle-resolved studies of quantum spin dynamics.
New Journal of Physics, May 2, 2018
We describe a compact, robust and versatile system for studying the macroscopic spin dynamics in ... more We describe a compact, robust and versatile system for studying the macroscopic spin dynamics in a spinor Bose-Einstein condensate. Condensates of Rb 87 are produced by all-optical evaporation in a 1560 nm optical dipole trap, using a non-standard loading sequence that employs an ancillary 1529 nm beam for partial compensation of the strong differential light-shift induced by the dipole trap itself. We use near-resonant Faraday rotation probing to non-destructively track the condensate magnetization, and demonstrate few-Larmor-cycle tracking with no detectable degradation of the spin polarization. In the ferromagnetic F=1 ground state, we observe the spin orientation between atoms in the condensate is preserved, such that they precess all together like one large spin in the presence of a magnetic field. We characterize this dynamics in terms of the single-shot magnetic coherence times 1 and 2 * , and observe them to be of several seconds, limited only by the residence time of the atoms in the trap. At the densities used, this residence is restricted only by one-body losses set by the vacuum conditions.
Revista de la Sociedad Colombiana de Física, 2007
Información del artículo Análisis de estados cuasiligados en junturas NISIN.
Physical review, Sep 10, 2019
arXiv (Cornell University), Apr 16, 2019
Revista de la Sociedad Colombiana de Física, 2005
En este trabajo se estudia la estabilidad de la cuantizacion de los estados de energia ligados re... more En este trabajo se estudia la estabilidad de la cuantizacion de los estados de energia ligados respecto a las fluctuaciones termicas en una juntura superconductor - metal en el estado normal - superconductor (SNS) con una diferencia de fase fija entre los superconductores. Se analiza el efecto de estas fluctuaciones sobre la coherencia de fase en dicha juntura. Esta coherencia se rompe cuando las cuasiparticulas en los estados no ligados son dispersadas debido a las fluctuaciones termicas antes de que estas puedan viajar de un superconductor al otro. Los estados de energia ligados permanecen cuantizados cuando las cuasiparticulas pueden viajar de un superconductor al otro y regresar al primero antes de ser dispersadas por efecto de las fluctuaciones. Dado que la coherencia de fase esta relacionada con los estados no ligados se muestra que su ruptura, debida a dichas fluctuaciones, no implica necesariamente la destruccion de la cuantizacion de los estados ligados.
Search &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Rescue satellite-based systems, ... more Search &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Rescue satellite-based systems, like COSPAS-SARSAT, are based in Time Of Arrival (TOA) and Frequency Of Arrival (FOA) techniques of the distress beacon signals relied by a set of satellites to calculate the emitter position. In this paper, we propose several algorithms to estimate time delays, Doppler shifts and message demodulation of such signals. Using the system specifications, it
arXiv (Cornell University), Feb 9, 2017
We present a non-perturbative numerical technique for calculating strong light shifts in atoms un... more We present a non-perturbative numerical technique for calculating strong light shifts in atoms under the influence of multiple optical fields with arbitrary polarization. We confirm our technique experimentally by performing spectroscopy of a cloud of cold 87 Rb atoms subjected to ∼ kW/cm 2 intensities of light at 1560.492 nm simultaneous with 1529.269 nm or 1529.282 nm. In these conditions the excited state resonances at 1529.26 nm and 1529.36 nm induce strong level mixing and the shifts are highly nonlinear. By absorption spectroscopy, we observe that the induced shifts of the 5P3/2 hyperfine Zeeman sublevels agree well with our theoretical predictions.. We propose the application of our theory and experiment to accurate measurements of excited-state electric-dipole matrix elements.
Proceedings of the National Academy of Sciences of the United States of America, Feb 7, 2022
We present a magnetic sensor with energy resolution per bandwidth ER <h. We show how a 87 Rb sing... more We present a magnetic sensor with energy resolution per bandwidth ER <h. We show how a 87 Rb single domain spinor Bose-Einstein condensate, detected by non-destructive Faraday-rotation probing, achieves single shot dc magnetic sensitivity of 49(11) fT/ √ Hz in a volume V = 1091(30) µm 3 , and thus ER = 0.070(16)h. We measure experimentally the condensate volume, spin coherence time, and readout noise, and use phase-space methods, backed by 3+1D mean-field simulations, to compute the spin noise. Contributions to the spin noise include one-body and three-body losses and shearing of the projection noise distribution, due to competition of ferromagnetic contact interactions and quadratic Zeeman shifts. Nonetheless, the fully-coherent nature of the single-domain, ultracold two-body interactions allows the system to escape the coherence vs. density trade-off that imposes an energy resolution limit on traditional spin-precession sensors. We predict that other Bose-condensed alkalis, especially the antiferromagnetic 23 Na, can further improve the energy resolution of this method.
We present precision measurements of the f=1 to f=2 inter-hyperfine scattering lengths in a singl... more We present precision measurements of the f=1 to f=2 inter-hyperfine scattering lengths in a single-domain ^87Rb spinor Bose-Einstein condensate. The inter-hyperfine interaction leads to a strong and state-dependent modification of the spin-mixing dynamics with respect to a non-interacting description. We employ hyperfine-specific Faraday-rotation probing to reveal the evolution of the transverse magnetization in each hyperfine manifold for different state preparations, and a co-magnetometer strategy to cancel laboratory magnetic noise. We find the scattering length ratios a_32^(12)/a_20^(1)=-1.27(15) and a_12^(12)/a_20^(1)=-1.31(13), limited by atom number fluctuations. Using better control of atom number, we estimate precisions of ∼ 0.3% should be possible with this technique.
Physical Review Letters, 2020
We describe a comagnetometer employing the f = 1 and f = 2 ground state hyperfine manifolds of a ... more We describe a comagnetometer employing the f = 1 and f = 2 ground state hyperfine manifolds of a 87 Rb spinor Bose-Einstein condensate as colocated magnetometers. The hyperfine manifolds feature nearly opposite gyromagnetic ratios and thus the sum of their precession angles is only weakly coupled to external magnetic fields, while being highly sensitive to any effect that rotates both manifolds in the same way. The f = 1 and f = 2 transverse magnetizations and azimuth angles are independently measured by nondestructive Faraday rotation probing, and we demonstrate a 44.0(8) dB common-mode rejection in good agreement with theory. We show how the magnetometer coherence time can be extended to ∼ 1 s, by using spin-dependent interactions to inhibit hyperfine relaxing collisions between f = 2 atoms. The technique could be used in high sensitivity searches for new physics on submillimeter length scales, precision studies of ultracold collision physics, and angle-resolved studies of quantum spin dynamics.
Bulletin of the American Physical Society, 2017
arXiv: Atomic Physics, 2017
We present a non-perturbative numerical technique for calculating strong light shifts in atoms un... more We present a non-perturbative numerical technique for calculating strong light shifts in atoms under the influence of multiple optical fields with arbitrary polarization. We confirm our technique experimentally by performing spectroscopy of a cloud of cold 87^{87}87Rb atoms subjected to sim\simsim kW/cm$^2$ intensities of light at 1560.492 nm simultaneous with 1529.269 nm or 1529.282 nm. In these conditions the excited state resonances at 1529.26 nm and 1529.36 nm induce strong level mixing and the shifts are highly nonlinear. By absorption spectroscopy, we observe that the induced shifts of the 5P3/2 hyperfine Zeeman sublevels agree well with our theoretical predictions.. We propose the application of our theory and experiment to accurate measurements of excited-state electric-dipole matrix elements.
Optics Express, 2021
We propose and demonstrate cavity-enhanced polarization-rotation measurement as a means to detect... more We propose and demonstrate cavity-enhanced polarization-rotation measurement as a means to detect magnetic effects in transparent media with greater sensitivity at equal optical disturbance to the medium. Using the Jones calculus, we compute the effective polarization rotation effect in a Fabry-Perot cavity containing a magnetic medium, including losses due to enclosure windows or other sources. The results show that when measuring polarization rotation, collecting the transmitted light has advantages in simplicity and linearity relative to collecting the reflected light. We demonstrate the technique by measuring Faraday rotation in a 87 Rb atomic ensemble in the single-pass and cavity-enhanced geometries, and observe enhancement in good agreement with the theoretical predictions. We also demonstrate shot-noise-limited operation of the enhanced rotation scheme in the small-angle regime.