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Sample records for ramsey-borde atom interferometers

  1. Combination of BLOCH oscillations with a Ramsey-Bordé interferometer: new determination of the fine structure constant.

    Science.gov (United States)

    Cadoret, Malo; de Mirandes, Estefania; Cladé, Pierre; Guellati-Khélifa, Saïda; Schwob, Catherine; Nez, François; Julien, Lucile; Biraben, François

    2008-12-01

    We report a new experimental scheme which combines atom interferometry with Bloch oscillations to provide a new measurement of the ratio h/mRb. By using Bloch oscillations, we impart to the atoms up to 1600 recoil momenta and thus we improve the accuracy on the recoil velocity measurement. The deduced value of h/mRb leads to a new determination of the fine structure constant alpha(-1) =137.03599945 (62) with a relative uncertainty of 4.6 x 10(-9). The comparison of this result with the value deduced from the measurement of the electron anomaly provides the most stringent test of QED.

  2. A trapped atom interferometer with ultracold Sr atoms

    CERN Document Server

    Zhang, Xian; Mazzoni, Tommaso; Poli, Nicola; Tino, Guglielmo M

    2016-01-01

    We report on a trapped atom interferometer based on Bragg diffraction and Bloch oscillations with alkaline-earth-metal atoms. We use a Ramsey-Bord\\'e Bragg interferometer with $^{88}$Sr atoms combined with Bloch oscillations to extend the interferometer time. Thanks to a long coherence time for Bloch oscillations of $^{88}$Sr atoms, we observed interference up to 1 s evolution time in the lattice. A detailed study of decoherence sources during the Bloch phase is also presented. While still limited in sensitivity by lattice lifetime and beam inhomogeneity this result opens the way to high contrast trapped interferometers with extended interrogation time.

  3. Measurement of the Aharonov-Casher geometric phase with a separated-arm atom interferometer

    CERN Document Server

    Gillot, Jonathan; Gauguet, Alexandre; Vigué, Jacques; Büchner, Matthias

    2013-01-01

    In this letter, we report a measurement of the Aharonov-Casher (AC) geometric phase with our lithium atom interferometer. The AC phase appears when a particle carrying a magnetic dipole propagates in a transverse electric field. The first measurement of the AC phase was done with a neutron interferometer in 1989 by A. Cimmino \\textit{et al.} (Phys. Rev. Lett. \\textbf{63}, 380, 1989) and all the following experiments were done with Ramsey or Ramsey-Bord\\'e interferometers with molecules or atoms. In our experiment, we use lithium atoms pumped in a single hyperfine-Zeeman sublevel and we measure the AC-phase by applying opposite electric fields on the two interferometer arms. Our measurements are in good agreement with the expected theoretical values and they prove that this phase is independent of the atom velocity.

  4. Measurement of the Aharonov-Casher geometric phase with a separated-arm atom interferometer

    Science.gov (United States)

    Gillot, Jonathan; Lepoutre, Steven; Gauguet, Alexandre; Vigué, Jacques; Büchner, Matthias

    2014-06-01

    In this letter, we report a measurement of the Aharonov-Casher (AC) geometric phase with our lithium atom interferometer. The AC phase appears when a particle carrying a magnetic dipole propagates in a transverse electric field. The first measurement of the AC phase was done with a neutron interferometer in 1989 by Cimmino et al. [Phys. Rev. Lett. 63, 380 (1989)] and all the following experiments were done with Ramsey or Ramsey-Bordé interferometers with molecules or atoms. In our experiment, we use lithium atoms pumped in a single hyperfine-Zeeman sublevel and we measure the AC-phase by applying opposite electric fields on the two interferometer arms. Our measurements are in good agreement with the expected theoretical values and they also provide a further test of the independence of the AC phase with the atom velocity.

  5. Atom Interferometry with up to 24-Photon-Momentum-Transfer Beam Splitters

    CERN Document Server

    Mueller, Holger; Long, Quan; Herrmann, Sven; Chu, Steven

    2007-01-01

    We present multi- (up to 24-)photon Bragg diffraction as beam splitter to achieve the largest splitting in momentum space in any light-pulse atom interferometer thus far. Relative to the 2-photon processes used in the most sensitive present interferometers, these large momentum transfer beam splitters increase the phase shift 12-fold for Mach-Zehnder and 144-fold for Ramsey-Borde geometries. As the atom's internal state is not changed, important systematic effects can cancel. This dramatic increase in sensitivity and precision opens the door to improved measurements of the fine-structure constant, inertial forces, and tests of relativity and quantum electrodynamics.

  6. Recoil-Sensitive Lithium Interferometer without a Subrecoil Sample.

    Science.gov (United States)

    Cassella, Kayleigh; Copenhaver, Eric; Estey, Brian; Feng, Yanying; Lai, Chen; Müller, Holger

    2017-06-09

    We report simultaneous conjugate Ramsey-Bordé interferometers with a sample of low-mass (lithium-7) atoms at 50 times the recoil temperature. We optically pump the atoms to a magnetically insensitive state using the 2S_{1/2}-2P_{1/2} line. Fast stimulated Raman beam splitters address a broad velocity class and unavoidably drive two conjugate interferometers that overlap spatially. We show that detecting the summed interference signals of both interferometers, using state labeling, allows recoil measurements and suppression of phase noise from vibrations. The use of "warm" atoms allows for simple, efficient, and high-flux atom sources and broadens the applicability of recoil-sensitive interferometry to particles that remain difficult to trap and cool.

  7. Atom-Light Hybrid Interferometer.

    Science.gov (United States)

    Chen, Bing; Qiu, Cheng; Chen, Shuying; Guo, Jinxian; Chen, L Q; Ou, Z Y; Zhang, Weiping

    2015-07-24

    A new type of hybrid atom-light interferometer is demonstrated with atomic Raman amplification processes replacing the beam splitting elements in a traditional interferometer. This nonconventional interferometer involves correlated optical and atomic waves in the two arms. The correlation between atoms and light developed with the Raman process makes this interferometer different from conventional interferometers with linear beam splitters. It is observed that the high-contrast interference fringes are sensitive to the optical phase via a path change as well as the atomic phase via a magnetic field change. This new atom-light correlated hybrid interferometer is a sensitive probe of the atomic internal state and should find wide applications in precision measurement and quantum control with atoms and photons.

  8. $T^3$-interferometer for atoms

    CERN Document Server

    Zimmermann, M; Roura, A; Schleich, W P; DeSavage, S A; Davis, J P; Srinivasan, A; Narducci, F A; Werner, S A; Rasel, E M

    2016-01-01

    The quantum mechanical propagator of a massive particle in a linear gravitational potential derived already in 1927 by Earle H. Kennard \\cite{Kennard,Kennard2} contains a phase that scales with the third power of the time $T$ during which the particle experiences the corresponding force. Since in conventional atom interferometers the internal atomic states are all exposed to the same acceleration $a$, this $T^3$-phase cancels out and the interferometer phase scales as $T^2$. In contrast, by applying an external magnetic field we prepare two different accelerations $a_1$ and $a_2$ for two internal states of the atom, which translate themselves into two different cubic phases and the resulting interferometer phase scales as $T^3$. We present the theoretical background for, and summarize our progress towards experimentally realizing such a novel atom interferometer.

  9. T 3-Interferometer for atoms

    Science.gov (United States)

    Zimmermann, M.; Efremov, M. A.; Roura, A.; Schleich, W. P.; DeSavage, S. A.; Davis, J. P.; Srinivasan, A.; Narducci, F. A.; Werner, S. A.; Rasel, E. M.

    2017-04-01

    The quantum mechanical propagator of a massive particle in a linear gravitational potential derived already in 1927 by Kennard [2, 3] contains a phase that scales with the third power of the time T during which the particle experiences the corresponding force. Since in conventional atom interferometers the internal atomic states are all exposed to the same acceleration a, this T^3-phase cancels out and the interferometer phase scales as T^2. In contrast, by applying an external magnetic field we prepare two different accelerations a_1 and a_2 for two internal states of the atom, which translate themselves into two different cubic phases and the resulting interferometer phase scales as T^3. We present the theoretical background for, and summarize our progress towards experimentally realizing such a novel atom interferometer.

  10. Atomic pair-state interferometer

    DEFF Research Database (Denmark)

    Nipper, J.; Balewski, Jonathan B.; Krupp, Alexander T.

    2012-01-01

    to measure the phase shift. Although the coupling between pair states is coherent on the time scale of the experiment, a loss of visibility occurs as a pair-state interferometer involves three simultaneously interfering paths and only one of them is phase shifted by the mutual interaction. Despite additional...... dephasing mechanisms, a pulsed Förster coupling sequence allows for observation of coherent dynamics around the Förster resonance....

  11. Gravitational Wave Detection with Single-Laser Atom Interferometers

    Science.gov (United States)

    Yu, Nan; Tinto, Massimo

    2011-01-01

    A new design for a broadband detector of gravitational radiation relies on two atom interferometers separated by a distance L. In this scheme, only one arm and one laser are used for operating the two atom interferometers. The innovation here involves the fact that the atoms in the atom interferometers are not only considered as perfect test masses, but also as highly stable clocks. Atomic coherence is intrinsically stable, and can be many orders of magnitude more stable than a laser.

  12. Atom Interferometers and the Gravitational Redshift

    CERN Document Server

    Sinha, Supurna

    2011-01-01

    Muller, Peters and Chu (MPC) claim that a reinterpretation of decade old experiments with atom interferometers leads to a sensitive test of the gravitational redshift effect. This claim has been disputed by Wolf et al (WBBRSC), who adduce arguments to show that MPC's claim is incorrect. In this Letter, we distill the arguments offered by WBBRSC to a single fundamental objection: an atom is not a clock ticking at the Compton frequency. We show that atom interferometric experiments conducted to date do not test the gravitational redshift effect. Our analysis is general and focuses on points of principle rather thanon the present state of technology. We then observe that it is in principle possible to use atom lasers to produce sensitive tests of the red shift effect at the Compton frequency. Such tests may become technologically realisable in the future.

  13. Laser-Ranging Long Baseline Differential Atom Interferometers for Space

    CERN Document Server

    Chiow, Sheng-wey; Yu, Nan

    2015-01-01

    High sensitivity differential atom interferometers are promising for precision measurements in science frontiers in space, including gravity field mapping for Earth science studies and gravitational wave detection. We propose a new configuration of twin atom interferometers connected by a laser ranging interferometer (LRI-AI) to provide precise information of the displacements between the two AI reference mirrors and a means to phase-lock the two independent interferometer lasers over long distances, thereby further enhancing the feasibility of long baseline differential atom interferometers. We show that a properly implemented LRI-AI can achieve equivalent functionality to the conventional differential atom interferometer measurement system. LRI-AI isolates the laser requirements for atom interferometers and for optical phase readout between distant locations, thus enabling optimized allocation of available laser power within a limited physical size and resource budget. A unique aspect of LRI-AI also enables...

  14. Analysis of a free oscillation atom interferometer

    CERN Document Server

    Kafle, Rudra P; Zozulya, Alex A

    2011-01-01

    We analyze a Bose-Einstein condensate (BEC) - based free oscillation atom Michelson interferometer in a weakly confining harmonic magnetic trap. A BEC at the center of the trap is split into two harmonics by a laser standing wave. The harmonics move in opposite directions with equal speeds and turn back under the influence of the trapping potential at their classical turning points. The harmonics are allowed to pass through each other and a recombination pulse is applied when they overlap at the end of a cycle after they return for the second time. We derive an expression for the contrast of the interferometric fringes and obtain the fundamental limit of performance of the interferometer in the parameter space.

  15. Atomic multiwave interferometer for Aharonov-Casher-phase measurements

    Science.gov (United States)

    Zhou, Min-Kang; Zhang, Ke; Duan, Xiao-Chun; Ke, Yi; Shao, Cheng-Gang; Hu, Zhong-Kun

    2016-02-01

    We present an atomic multiwave interferometer with magnetic sublevels to precisely determine the Aharonov-Casher (AC) geometric phase. Simulations show that this interferometer has sharper fringes than a normal two-wave interferometer, which means a higher phase resolution can be achieved. Moreover, atoms evolving in a single hyperfine structure state make the interferometer insensitive to the dc Stark phase shift. This dc Stark shift is one of the main noise sources in AC phase measurements. The constraint of the photon rest mass is also discussed when using this atomic interferometer to measure the Aharonov-Casher phase.

  16. Comparative Sensitivities of Gravitational Wave Detectors Based on Atom Interferometers and Light Interferometers

    Science.gov (United States)

    Baker, John G.; Thorpe, J. I.

    2012-01-01

    We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe. Whether this potential advantage outweighs the additional complexity associated with including atom interferometers will require further study.

  17. Vibration induced phase noise in Mach-Zehnder atom interferometers

    CERN Document Server

    Miffre, A; Büchner, M; Trénec, G; Vigué, J; Miffre, Alain; Jacquey, Marion; B\\"{u}chner, Matthias; Vigu\\'{e}, Jacques

    2006-01-01

    The high inertial sensitivity of atom interferometers has been used to build accelerometers and gyrometers but this sensitivity makes these interferometers very sensitive to the laboratory seismic noise. This seismic noise induces a phase noise which is large enough to reduce the fringe visibility in many cases. We develop here a model calculation of this phase noise in the case of Mach-Zehnder atom interferometers and we apply this model to our thermal lithium interferometer. We are thus able to explain the observed dependence of the fringe visibility with the diffraction order. The dynamical model developed in the present paper should be very useful to further reduce this phase noise in atom interferometers and this reduction should open the way to improved interferometers.

  18. Comparison of Atom Interferometers and Light Interferometers as Space-Based Gravitational Wave Detectors

    Science.gov (United States)

    Baker, John G.

    2012-01-01

    We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe.

  19. Comparison of atom interferometers and light interferometers as space-based gravitational wave detectors.

    Science.gov (United States)

    Baker, John G; Thorpe, J I

    2012-05-25

    We consider a class of proposed gravitational-wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, noninertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g., multiple-arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and, in principle, favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe.

  20. Wave-particle duality in a Raman atom interferometer

    Science.gov (United States)

    Jia, Ai-Ai; Yang, Jun; Yan, Shu-Hua; Hu, Qing-Qing; Luo, Yu-Kun; Zhu, Shi-Yao

    2015-08-01

    We theoretically investigate the wave-particle duality based on a Raman atom interferometer, via the interaction between the atom and Raman laser, which is similar to the optical Mach-Zehnder interferometer. The wave and which-way information are stored in the atomic internal states. For the φ - π - π/2 type of atom interferometer, we find that the visibility (V) and predictability (P) still satisfy the duality relation, P2 + V2 ≤ 1. Project supported by the National Natural Science Foundation of China (Grant No. 51275523) and the Special Research Found for the Doctoral Program of Higher Education, China (Grant No. 20134307110009).

  1. 102ℏk large area atom interferometers.

    Science.gov (United States)

    Chiow, Sheng-wey; Kovachy, Tim; Chien, Hui-Chun; Kasevich, Mark A

    2011-09-23

    We demonstrate atom interferometers utilizing a novel beam splitter based on sequential multiphoton Bragg diffractions. With this sequential Bragg large momentum transfer (SB-LMT) beam splitter, we achieve high contrast atom interferometers with momentum splittings of up to 102 photon recoil momenta (102ℏk). To our knowledge, this is the highest momentum splitting achieved in any atom interferometer, advancing the state-of-the-art by an order of magnitude. We also demonstrate strong noise correlation between two simultaneous SB-LMT interferometers, which alleviates the need for ultralow noise lasers and ultrastable inertial environments in some future applications. Our method is intrinsically scalable and can be used to dramatically increase the sensitivity of atom interferometers in a wide range of applications, including inertial sensing, measuring the fine structure constant, and detecting gravitational waves.

  2. Atom interferometer as a selective sensor of rotation or gravity

    CERN Document Server

    Dubetsky, B

    2006-01-01

    In the presence of Earth gravity and gravity-gradient forces, centrifugal and Coriolis forces caused by the Earth rotation, the phase of the time-domain atom interferometers is calculated with accuracy up to the terms proportional to the fourth degree of the time separation between pulses. We considered double-loop atom interferometers and found appropriate condition to eliminate their sensitivity to acceleration to get atomic gyroscope, or to eliminate the sensitivity to rotation to increase accuracy of the atomic gravimeter. Consequent use of these interferometers allows one to measure all components of the acceleration and rotation frequency projection on the plane perpendicular to gravity acceleration. Atom interference on the Raman transition driving by non-counterpropagating optical fields is proposed to exclude stimulated echo processes which can affect the accuracy of the atomic gyroscopes. Using non-counterpropagating optical fields allows one to get new type of the Ramsey fringes arising in the unid...

  3. An atom interferometer with a shaken optical lattice

    CERN Document Server

    Weidner, C A; Kosloff, Ronnie; Anderson, and Dana Z

    2016-01-01

    We introduce shaken lattice interferometry with atoms trapped in a one-dimensional optical lattice. The atoms undergo an interferometer sequence of splitting, propagation, reflection, and recombination by phase modulation of the lattice through a sequence of shaking functions. Each function in the sequence is determined by a learning procedure that is implemented with a genetic algorithm. Numerical simulations determine the momentum state of the atoms, which is experimentally accessible with time-of-flight imaging. The shaking function is then optimized to achieve the desired state transitions. The sensitivity of the interferometer to perturbations such as those introduced by inertial forces scales the same way as for conventional matter wave interferometers. The shaken lattice interferometer may be optimized to sense signals of interest while rejecting others, such as the measurement of an AC signal while rejecting a DC bias.

  4. Design of a dual species atom interferometer for space

    CERN Document Server

    Schuldt, Thilo; Krutzik, Markus; Bote, Lluis Gesa; Gaaloul, Naceur; Hartwig, Jonas; Ahlers, Holger; Herr, Waldemar; Posso-Trujillo, Katerine; Rudolph, Jan; Seidel, Stephan; Wendrich, Thijs; Ertmer, Wolfgang; Herrmann, Sven; Kubelka-Lange, André; Milke, Alexander; Rievers, Benny; Rocco, Emanuele; Hinton, Andrew; Bongs, Kai; Oswald, Markus; Franz, Matthias; Hauth, Matthias; Peters, Achim; Bawamia, Ahmad; Wicht, Andreas; Battelier, Baptiste; Bertoldi, Andrea; Bouyer, Philippe; Landragin, Arnaud; Massonnet, Didier; Lévèque, Thomas; Wenzlawski, Andre; Hellmig, Ortwin; Windpassinger, Patrick; Sengstock, Klaus; von Klitzing, Wolf; Chaloner, Chris; Summers, David; Ireland, Philip; Mateos, Ignacio; Sopuerta, Carlos F; Sorrentino, Fiodor; Tino, Guglielmo M; Williams, Michael; Trenkel, Christian; Gerardi, Domenico; Chwalla, Michael; Burkhardt, Johannes; Johann, Ulrich; Heske, Astrid; Wille, Eric; Gehler, Martin; Cacciapuoti, Luigi; Gürlebeck, Norman; Braxmaier, Claus; Rasel, Ernst

    2014-01-01

    Atom interferometers have a multitude of proposed applications in space including precise measurements of the Earth's gravitational field, in navigation & ranging, and in fundamental physics such as tests of the weak equivalence principle (WEP) and gravitational wave detection. While atom interferometers are realized routinely in ground-based laboratories, current efforts aim at the development of a space compatible design optimized with respect to dimensions, weight, power consumption, mechanical robustness and radiation hardness. In this paper, we present a design of a high-sensitivity differential dual species $^{85}$Rb/$^{87}$Rb atom interferometer for space, including physics package, laser system, electronics and software. The physics package comprises the atom source consisting of dispensers and a 2D magneto-optical trap (MOT), the science chamber with a 3D-MOT, a magnetic trap based on an atom chip and an optical dipole trap (ODT) used for Bose-Einstein condensate (BEC) creation and interferometry...

  5. Probing angular momentum coherence in a twin-atom interferometer

    CERN Document Server

    de Carvalho, Carlos R; Impens, François; Robert, J; Medina, Aline; Zappa, F; Faria, N V de Castro

    2014-01-01

    We propose to use a double longitudinal Stern-Gerlach atom interferometer in order to investigate quantitatively the angular momentum coherence of molecular fragments. Assuming that the dissociated molecule has a null total angular momentum, we investigate the propagation of the corresponding atomic fragments in the apparatus. We show that the envisioned interferometer enables one to distinguish unambiguously a spin-coherent from a spin-incoherent dissociation, as well as to estimate the purity of the angular momentum density matrix associated with the fragments. This setup, which may be seen as an atomic analogue of a twin-photon interferometer, can be used to investigate the suitability of molecule dissociation processes -- such as the metastable hydrogen atoms H($2^2 S$)-H($2^2 S$) dissociation - for coherent twin-atom optics.

  6. A Robust Ramsey Interferometer for Atomic Timekeeping in Dynamic Environments

    Science.gov (United States)

    Kotru, Krish; Brown, Justin; Butts, David; Choy, Jennifer; Galfond, Marissa; Johnson, David M.; Kinast, Joseph; Timmons, Brian; Stoner, Richard

    2014-05-01

    We present a laser-based approach to atomic timekeeping, in which atomic phase information is extracted using modified Raman pulses in a Ramsey sequence. We overcome systematic effects associated with differential AC Stark shifts by employing atom optics derived from Raman adiabatic rapid passage (ARP). ARP drives coherent transfer between two hyperfine ground states by sweeping the frequency difference of two optical fields and maintaining a large single-photon detuning. Compared to resonant, pulsed Raman transitions, ARP atom optics afford a >150x reduction in sensitivity to differential AC Stark shifts in a Ramsey interferometer. We also demonstrate that ARP preserves fringe contrast in Ramsey interferometers for cloud displacements reaching the 1/e2 intensity radius of the laser beam. ARP can thus be expected to improve the robustness of clock interferometers operating in dynamic environments. Copyright ©2014 by The Charles Stark Draper Laboratory, Inc. All rights reserved.

  7. Observation of saturation of fidelity decay with an atom interferometer.

    Science.gov (United States)

    Wu, Saijun; Tonyushkin, Alexey; Prentiss, Mara G

    2009-07-17

    We use an atom interferometer to investigate the dynamics of matter waves in a periodically pulsed optical standing wave: an atom optics realization of the quantum kicked rotor that exhibits chaotic classical dynamics. We experimentally show that a measure of the coherence between the interferometer diffraction orders can revive after a quick initial loss, and can approach a finite asymptote as the number of kicks increases. This observation demonstrates that quantum fidelity of a classically chaotic system can survive strong perturbations over long times without decay.

  8. Ultra-sensitive atomic spin measurements with a nonlinear interferometer

    CERN Document Server

    Sewell, R J; Behbood, N; Colangelo, G; Ciurana, F Martin; Mitchell, M W

    2013-01-01

    Quantum metrology studies and improves quantum-limited ultra-sensitive measurements. Both linear interferometers, e.g. gravitational wave observatories, and nonlinear interferometers, e.g. optical magnetometers, have been enhanced by quantum metrology. The sensitivities of nonlinear interferometers scale better with system size than even quantum-enhanced linear interferometers, so-called `super-Heisenberg scaling', but it is actively debated whether this scaling can lead to better absolute sensitivity. Here we demonstrate a nonlinear measurement that surpasses, through super-Heisenberg scaling, the best possible linear measurement of the same quantity. We use alignment-to-orientation conversion, a practical magnetometry technique, to make a quantum non-demolition measurement of the spin alignment of a sample of $^{87}$Rb atoms. We observe absolute sensitivity 9 dB beyond the best comparable linear measurement and measurement-induced spin squeezing. The results provide insight into ultra-sensitive magnetometer...

  9. High data-rate atom interferometers through high recapture efficiency

    Science.gov (United States)

    Biedermann, Grant; Rakholia, Akash Vrijal; McGuinness, Hayden

    2015-01-27

    An inertial sensing system includes a magneto-optical trap (MOT) that traps atoms within a specified trapping region. The system also includes a cooling laser that cools the trapped atoms so that the atoms remain within the specified region for a specified amount of time. The system further includes a light-pulse atom interferometer (LPAI) that performs an interferometric interrogation of the atoms to determine phase changes in the atoms. The system includes a controller that controls the timing of MOT and cooling laser operations, and controls the timing of interferometric operations to substantially recapture the atoms in the specified trapping region. The system includes a processor that determines the amount inertial movement of the inertial sensing system based on the determined phase changes in the atoms. Also, a method of inertial sensing using this inertial sensing system includes recapture of atoms within the MOT following interferometric interrogation by the LPAI.

  10. Demonstration of a Sagnac-Type Cold Atom Interferometer with Stimulated Raman Transitions

    Institute of Scientific and Technical Information of China (English)

    WANG Ping; LI Run-Bing; YAN Hui; WANG Jin; ZHAN Ming-Sheng

    2007-01-01

    @@ Cold-matter-wave Sagnac interferometers possess many advantages over their thermal atomic beam counterparts when they are used as precise inertial sensors. We report a realization of a Sagnac-type interferometer with cold atoms.

  11. Coherent population trapping in a Raman atom interferometer

    CERN Document Server

    Cheng, Bing; Merlet, Sébastien; Santos, Franck Pereira dos

    2016-01-01

    We investigate the effect of coherent population trapping (CPT) in an atom inter-ferometer gravimeter based on the use of stimulated Raman transitions. We find that CPT leads to significant phase shifts, of order of a few mrad, which may compromise the accuracy of inertial measurements. We show that this effect is rejected by the k-reversal technique, which consists in averaging inertial measurements performed with two opposite orientations of the Raman wavevector k, provided that internal states at the input of the interferometer are kept identical for both configurations.

  12. A double well interferometer on an atom chip

    DEFF Research Database (Denmark)

    Schumm, Thorsten; Krüger, Peter; Hofferberth, S.

    2006-01-01

    Radio-Frequency coupling between magnetically trapped atomic states allows to create versatile adiabatic dressed state potentials for neutral atom manipulation. Most notably, a single magnetic trap can be split into a double well by controlling amplitude and frequency of an oscillating magnetic...... field. We use this to build an integrated matter wave interferometer on an atom chip. Transverse splitting of quasi one-dimensional Bose-Einstein condensates over a wide range from 3 to 80 μm is demonstrated, accessing the tunnelling regime as well as completely isolated sites. By recombining the two...... the splitting process. RF induced potentials are especially suited for integrated micro manipulation of neutral atoms on atom chips: designing appropriate wire patterns enables control over the created potentials to the (nanometer) precision of the fabrication process. Additionally, hight local RF amplitudes...

  13. A Multi-Path Interferometer on an Atom Chip

    CERN Document Server

    Petrovic, Jovana; Lombardi, Pietro; Cataliotti, Francesco S

    2011-01-01

    Cold-atom interferometry is a powerful tool for high-precision measurements of the quantum properties of atoms, many-body interactions and gravity. Further enhancement of sensitivity and reduction of complexity of these devices are crucial conditions for success of their applications. Here we introduce a multi-path interferometric scheme that offers advances in both these aspects. It uses coherent coupling between Bose-Einstein condensates in different Zeeman states to generate an interferometric signal with sharp fringes. We realise such an interferometer as a compact easy-to-use atom-chip device and thus provide an alternative method for measurement of the light-atom and surface-atom interactions.

  14. Design of a dual species atom interferometer for space

    Science.gov (United States)

    Schuldt, Thilo; Schubert, Christian; Krutzik, Markus; Bote, Lluis Gesa; Gaaloul, Naceur; Hartwig, Jonas; Ahlers, Holger; Herr, Waldemar; Posso-Trujillo, Katerine; Rudolph, Jan; Seidel, Stephan; Wendrich, Thijs; Ertmer, Wolfgang; Herrmann, Sven; Kubelka-Lange, André; Milke, Alexander; Rievers, Benny; Rocco, Emanuele; Hinton, Andrew; Bongs, Kai; Oswald, Markus; Franz, Matthias; Hauth, Matthias; Peters, Achim; Bawamia, Ahmad; Wicht, Andreas; Battelier, Baptiste; Bertoldi, Andrea; Bouyer, Philippe; Landragin, Arnaud; Massonnet, Didier; Lévèque, Thomas; Wenzlawski, Andre; Hellmig, Ortwin; Windpassinger, Patrick; Sengstock, Klaus; von Klitzing, Wolf; Chaloner, Chris; Summers, David; Ireland, Philip; Mateos, Ignacio; Sopuerta, Carlos F.; Sorrentino, Fiodor; Tino, Guglielmo M.; Williams, Michael; Trenkel, Christian; Gerardi, Domenico; Chwalla, Michael; Burkhardt, Johannes; Johann, Ulrich; Heske, Astrid; Wille, Eric; Gehler, Martin; Cacciapuoti, Luigi; Gürlebeck, Norman; Braxmaier, Claus; Rasel, Ernst

    2015-06-01

    Atom interferometers have a multitude of proposed applications in space including precise measurements of the Earth's gravitational field, in navigation & ranging, and in fundamental physics such as tests of the weak equivalence principle (WEP) and gravitational wave detection. While atom interferometers are realized routinely in ground-based laboratories, current efforts aim at the development of a space compatible design optimized with respect to dimensions, weight, power consumption, mechanical robustness and radiation hardness. In this paper, we present a design of a high-sensitivity differential dual species 85Rb/87Rb atom interferometer for space, including physics package, laser system, electronics and software. The physics package comprises the atom source consisting of dispensers and a 2D magneto-optical trap (MOT), the science chamber with a 3D-MOT, a magnetic trap based on an atom chip and an optical dipole trap (ODT) used for Bose-Einstein condensate (BEC) creation and interferometry, the detection unit, the vacuum system for 10-11 mbar ultra-high vacuum generation, and the high-suppression factor magnetic shielding as well as the thermal control system. The laser system is based on a hybrid approach using fiber-based telecom components and high-power laser diode technology and includes all laser sources for 2D-MOT, 3D-MOT, ODT, interferometry and detection. Manipulation and switching of the laser beams is carried out on an optical bench using Zerodur bonding technology. The instrument consists of 9 units with an overall mass of 221 kg, an average power consumption of 608 W (814 W peak), and a volume of 470 liters which would well fit on a satellite to be launched with a Soyuz rocket, as system studies have shown.

  15. Development of an Atom Interferometer Gravity Gradiometer for Earth Sciences

    Science.gov (United States)

    Rakholia, A.; Sugarbaker, A.; Black, A.; Kasecivh, M.; Saif, B.; Luthcke, S.; Callahan, L.; Seery, B.; Feinberg, L.; Mather, J.; hide

    2017-01-01

    We report progress towards a prototype atom interferometer gravity gradiometer for Earth science studies from a satellite in low Earth orbit.The terrestrial prototype has a target sensitivity of 8 x 10(exp -2) E/Hz(sup 1/2) and consists of two atom sources running simultaneous interferometers with interrogation time T = 300 ms and 12 hk photon recoils, separated by a baseline of 2 m. By employing Raman side band cooling and magnetic lensing, we will generate atomic ensembles with N = 10(exp 6) atoms at a temperature of 3 nK. The sensitivity extrapolates to 7 x 10(exp -5) E/Hz(sup 1/2) in microgravity on board a satellite. Simulations derived from this sensitivity demonstrate a monthly time-variable gravity accuracy of 1 cm equivalent water height at 200 km resolution, yielding an improvement over GRACE by 1-2 orders of magnitude. A gravity gradiometer with this sensitivity would also benefit future planetary, lunar, and asteroidal missions.

  16. Atom optical shop testing of electrostatic lenses using an atom interferometer

    CERN Document Server

    Hromada, Ivan; Holmgren, William F; Gregoire, Maxwell D; Cronin, Alexander D

    2013-01-01

    We used an atom interferometer for atom optical shop testing of lenses for atomic de Broglie waves. We measured focal lengths and spherical aberrations of electrostatic lenses in three independent ways based on contrast data, phase data, or calculations of de Broglie wavefront curvature. We report focal lengths of -2.5 km and -21.7 km with 5% uncertainty for different lenses. All three methods give consistent results. Understanding how lenses magnify and distort atom interference fringes helps improve atom beam velocity measurements made with phase choppers [New J. Phys. 13, 115007 (2011)], which in turn will improve the accuracy of atomic polarizability measurements.

  17. Development of an atomic gravimeter based on atom interferometer

    Science.gov (United States)

    Kwon, Taeg Yong; Lee, Sang-Bum; Park, Sang Eon; Heo, Myoung-Sun; Hong, Hyun-Gue; Park, Chang Yong; Lee, Won-Kyu; Yu, Dai-Hyuk

    2015-05-01

    We present an atomic gravimeter under development at KRISS in Korea for precise measurement of absolute gravity. It is based on atomic interference of laser cooled 87Rb atoms in free fall. The temperature of the atoms is cooled to about 5 μK in a magneto-optic trap. Three Raman light pulses are applied for splitting, reflecting and recombining the atoms clouds while the atoms are in free fall. The pulse width and spacing time of Raman pulses is 40 μs and about 50 ms, respectively. During the interferometry, the frequency difference between the two counter-propagating Raman beams is chirped to compensate for Doppler shift induced by gravitational acceleration. The interference signals are measured at different spacing times to find the chirping rate at which the phase of interference fringe is independent of the spacing time. The chirping rate (~ 25.1 MHz/s) corresponds to g .keff/2 π, where keff = k1 +k2 (k1 and k2 are wave numbers for two Raman beams). At present, we are going to introduce an anti-vibration platform and a magnetic shield for accuracy evaluation of the gravimeter. In the presentation, the preliminary results of the KRISS gravimeter will be discussed.

  18. Lithium recoil measurement without a subrecoil sample

    CERN Document Server

    Cassella, Kayleigh; Estey, Brian; Feng, Yanying; Lai, Chen; Müller, Holger

    2016-01-01

    We report both the first atom interferometer with a low-mass, laser-cooled atom (lithium-7) and the first simultaneous conjugate Ramsey-Bord\\'e interferometers with an atomic ensemble not cooled or selected to subrecoil speeds. Above the recoil temperature, fast thermal motion of atoms leads to overlapped interferometers whose outputs tend to cancel. We avoid such cancellation using the two-photon detuning from Raman resonance to control the relative phase between these conjugate interferometers. To prevent magnetic dephasing, we present optical pumping to the magnetically-insensitive state using the well-resolved $D_1$ line. These techniques allow the use of "warm" atoms for Ramsey-Bord\\'e interferometers, which broadens the choice of species, simplifies cooling, increases available atom number and reduces cycle time for faster integration.

  19. Measuring the Earth's gravity field with cold atom interferometers

    CERN Document Server

    Carraz, Olivier; Massotti, Luca; Haagmans, Roger; Silvestrin, Pierluigi

    2015-01-01

    The scope of the paper is to propose different concepts for future space gravity missions using Cold Atom Interferometers (CAI) for measuring the diagonal elements of the gravity gradient tensor, the spacecraft angular velocity and the spacecraft acceleration. The aim is to achieve better performance than previous space gravity missions due to a very low white noise spectral behaviour of the CAI instrument and a very high common mode rejection, with the ultimate goals of determining the fine structures of the gravity field with higher accuracy than GOCE and detecting time-variable signals in the gravity field.

  20. Atom interferometer gyroscope with spin-dependent phase shifts induced by light near a tune-out wavelength.

    Science.gov (United States)

    Trubko, Raisa; Greenberg, James; Germaine, Michael T St; Gregoire, Maxwell D; Holmgren, William F; Hromada, Ivan; Cronin, Alexander D

    2015-04-10

    Tune-out wavelengths measured with an atom interferometer are sensitive to laboratory rotation rates because of the Sagnac effect, vector polarizability, and dispersion compensation. We observed shifts in measured tune-out wavelengths as large as 213 pm with a potassium atom beam interferometer, and we explore how these shifts can be used for an atom interferometer gyroscope.

  1. Atom Interferometer Gyroscope with Spin-Dependent Phase Shifts Induced by Light near a Tune-Out Wavelength

    CERN Document Server

    Trubko, Raisa; Germaine, Michael T St; Gregoire, Maxwell D; Holmgren, William F; Hromada, Ivan; Cronin, Alexander D

    2015-01-01

    Tune-out wavelengths measured with an atom interferometer are sensitive to laboratory rotation rates because of the Sagnac effect, vector polarizability, and dispersion compensation. We observed shifts in measured tune-out wavelengths as large as 213 pm with a potassium atom beam interferometer, and we explore how these shifts can be used for an atom interferometer gyroscope.

  2. Collisional Decoherence in Trapped-Atom Interferometers that use Nondegenerate Sources

    Science.gov (United States)

    2009-01-22

    atomic cloud experiences a nonuniform potential during the interferometer cycle, the density echoes will be shifted relative to the initial modula- tion...verify the analytic model. 15. SUBJECT TERMS Topside ionosphere Electron density Ionospheric model Altitude profile 16. SECURITY CLASSIFICATION OF: a...sensitive free space atom in- terferometers, the atomic clouds travel up to 10 meters [21. The large scale of free space interferometers limits their

  3. Rabi oscillation induced $\\pi$-phase flip in an unbalanced Ramsey atom interferometer

    CERN Document Server

    Li, R B; Wang, K; Lu, S B; Cao, L; Wang, J; Zhan, M S

    2016-01-01

    We present an observation of zero to $\\pi$ phase flips induced by Rabi oscillation in an unbalanced Ramsey atom interferometer. The phase shift and visibility are experimentally investigated by modulating either the polarization or the pulse duration of Raman lasers, and they are well explained by a theoretical model. In an atom interferometer, the $\\pi$-phase flips are caused not only by the sign of Rabi frequency but also by the amplitude of Rabi oscillation. Considering these $\\pi$-phase flips, we propose a composite-light-pulse sequence for realizing cold atom interferometers, which has advantages of the large momentum transfer and the better noise immunity.

  4. Atom Michelson interferometer on a chip using a Bose-Einstein condensate.

    Science.gov (United States)

    Wang, Ying-Ju; Anderson, Dana Z; Bright, Victor M; Cornell, Eric A; Diot, Quentin; Kishimoto, Tetsuo; Prentiss, Mara; Saravanan, R A; Segal, Stephen R; Wu, Saijun

    2005-03-11

    An atom Michelson interferometer is implemented on an "atom chip." The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms.

  5. Simultaneous measurement of gravity acceleration and gravity gradient with an atom interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Sorrentino, F.; Lien, Y.-H.; Rosi, G.; Tino, G. M. [Dipartimento di Fisica e Astronomia and LENS, Universita di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); Bertoldi, A. [Laboratoire Charles Fabry de l' Institut d' Optique, CNRS and Universite Paris-Sud Campus Polytechnique, RD 128, F-91127 Palaiseau cedex (France); Bodart, Q. [Dipartimento di Fisica e Astronomia and LENS, Universita di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); European Space Agency, Research and Scientific Support Department, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Cacciapuoti, L. [European Space Agency, Research and Scientific Support Department, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Angelis, M. de [Istituto di Fisica Applicata ' Nello Carrara' CNR, via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Prevedelli, M. [Dipartimento di Fisica dell' Universita di Bologna, Via Irnerio 46, I-40126, Bologna (Italy)

    2012-09-10

    We demonstrate a method to measure the gravitational acceleration with a dual cloud atom interferometer; the use of simultaneous atom interferometers reduces the effect of seismic noise on the gravity measurement. At the same time, the apparatus is capable of accurate measurements of the vertical gravity gradient. The ability to determine the gravity acceleration and gravity gradient simultaneously and with the same instrument opens interesting perspectives in geophysical applications.

  6. Measuring the atomic recoil frequency using a perturbative grating-echo atom interferometer

    CERN Document Server

    Barrett, B; Beattie, S; Kumarakrishnan, A

    2012-01-01

    We describe progress toward a precise measurement of the recoil energy of an atom measured using a unique perturbative grating-echo atom interferometer (AI) that involves three standing-wave (sw) pulses. Experiments are performed using samples of laser-cooled rubidium atoms with temperatures <5 uK in a non-magnetic apparatus. The AI signal exhibits narrow fringes that revive periodically at the two-photon recoil frequency, omega_q, as a function of the third sw pulse time. Using this technique, we demonstrate a measurement of omega_q with a statistical uncertainty of 37 parts per 10^9 (ppb) on a time scale of ~45 ms in 14 hours. Further statistical improvements are anticipated by extending this time scale and narrowing the signal fringe width. However, the estimated systematic uncertainty is ~6 parts per 10^6 (ppm). We describe methods of reducing these systematic errors to competitive levels.

  7. Measuring the weak value of momentum in a double slit atom interferometer

    Science.gov (United States)

    Morley, J.; Edmunds, P. D.; Barker, P. F.

    2016-03-01

    We describe the development of an experiment to measure the weak value of the transverse momentum operator (local momentum [1]) of cold atoms passing through a matter- wave interferometer. The results will be used to reconstruct the atom's average trajectories. We describe our progress towards this goal using laser cooled argon atoms.

  8. Phase noise due to vibrations in Mach-Zehnder atom interferometers

    CERN Document Server

    Miffre, A; Büchner, M; Trénec, G; Vigué, J

    2006-01-01

    Atom interferometers are very sensitive to accelerations and rotations. This property, which has some very interesting applications, induces a deleterious phase noise due to the seismic noise of the laboratory and this phase noise is sufficiently large to reduce the fringe visibility in many experiments. We develop a model calculation of this phase noise in the case of Mach-Zehnder atom interferometers and we apply this model to our thermal lithium interferometer. We are able to explain the observed phase noise which has been detected through the rapid dependence of the fringe visibility with the diffraction order. We think that the dynamical model developed in the present paper should be very useful to reduce the vibration induced phase noise in atom interferometers, making many new experiments feasible.

  9. Effects of losses in the atom-light hybrid SU(1,1) interferometer.

    Science.gov (United States)

    Chen, Zhao-Dan; Yuan, Chun-Hua; Ma, Hong-Mei; Li, Dong; Chen, L Q; Ou, Z Y; Zhang, Weiping

    2016-08-08

    Collective atomic excitation can be realized by the Raman scattering. Such a photon-atom interface can form an SU(1,1)-typed atom-light hybrid interferometer, where the atomic Raman amplification processes take the place of the beam splitting elements in a traditional Mach-Zehnder interferometer. We numerically calculate the phase sensitivities and the signal-to-noise ratios (SNRs) of this interferometer with the method of homodyne detection and intensity detection, and give their differences of the optimal phase points to realize the best phase sensitivities and the maximal SNRs from these two detection methods. The difference of the effects of loss of light field and atomic decoherence on measure precision is analyzed.

  10. Raman pulse duration effect in gravity gradiometers composed of two atom interferometers

    CERN Document Server

    Shao, Cheng-Gang; Zhou, Min-Kang; Tan, Yu-Jie; Chen, Le-Le; Luo, Jun; Kun-Hu, Zhong

    2015-01-01

    We investigated the Raman pulse duration effect in a gravity gradiometer with two atom interferometers. Since the two atom clouds in the gradiometer experience different gravitational fields, it is hard to compensate the Doppler shifts of the two clouds simultaneously by chirping the frequency of a common Raman laser, which leads to an appreciable phase shift. When applied to an experiment measuring the Newtonian gravitational constant G, the effect contributes to a systematic offset as large as -49ppm in Nature 510, 518 (2014). Thus an underestimated value of G measured by atom interferometers can be partly explained due to this effect.

  11. Dual-axis, high data-rate atom interferometer via cold ensemble exchange

    CERN Document Server

    Rakholia, Akash V; Biedermann, Grant W

    2014-01-01

    We demonstrate a dual-axis accelerometer and gyroscope atom interferometer, which forms the building blocks of a six-axis inertial measurement unit. By recapturing the atoms after the interferometer sequence, we maintain a large atom number at high data-rates of 50 to 100 measurements per second. Two cold ensembles are formed in trap zones located a few centimeters apart, and are launched toward one-another. During their ballistic trajectory, they are interrogated with a stimulated Raman sequence, detected, and recaptured in the opposing trap zone. We achieve sensitivities at $\\mathrm{\\mu \\mathit{g} / \\sqrt{Hz}}$ and $\\mathrm{\\mu rad / s / \\sqrt{Hz}}$ levels, making this a compelling prospect for expanding the use of atom interferometer inertial sensors beyond benign laboratory environments.

  12. Raman-pulse-duration effect in gravity gradiometers composed of two atom interferometers

    Science.gov (United States)

    Shao, Cheng-Gang; Mao, De-Kai; Zhou, Min-Kang; Tan, Yu-Jie; Chen, Le-Le; Luo, Jun; Hu, Zhong-Kun

    2015-11-01

    We investigated the Raman-pulse-duration effect in a gravity gradiometer with two atom interferometers. Since the two atom clouds in the gradiometer experience different gravitational fields, it is hard to compensate for the Doppler shifts of the two clouds simultaneously by chirping the frequency of a common Raman laser. This leads to an appreciable phase shift. The magnitude of the phase shift relative to the differential phase shift of the two interferometers is in an order of τ /T , and cannot be neglected in the precision measurements such as measuring the gravity gradient and the Newtonian gravitational constant.

  13. Coupled dynamics of atoms and radiation pressure driven interferometers

    OpenAIRE

    Meiser, D.; Meystre, P.

    2005-01-01

    We consider the motion of the end mirror of a cavity in whose standing wave mode pattern atoms are trapped. The atoms and the light field strongly couple to each other because the atoms form a distributed Bragg mirror with a reflectivity that can be fairly high. We analyze how the dipole potential in which the atoms move is modified due to this backaction of the atoms. We show that the position of the atoms can become bistable. These results are of a more general nature and can be applied to ...

  14. High-order inertial phase shifts for time-domain atom interferometers

    CERN Document Server

    Bongs, K; Kasevich, M A; Bongs, Kai; Launay, Romain; Kasevich, Mark A.

    2002-01-01

    High-order inertial phase shifts are calculated for time-domain atom interferometers. We obtain closed-form analytic expressions for these shifts in accelerometer, gyroscope, optical clock and photon recoil measurement configurations. Our analysis includes Coriolis, centrifugal, gravitational, and gravity gradient-induced forces. We identify new shifts which arise at levels relevant to current and planned experiments.

  15. Multimode Kapitza-Dirac interferometer on Bose-Einstein condensates with atomic interactions

    Science.gov (United States)

    He, Tianchen; Niu, Pengbin

    2017-03-01

    The dynamics of multimode interferometers for Bose Einstein condensation (BEC) with atomic interactions confined to a harmonic trap is investigated. At the initial time t = 0, several spatially addressable wave packets (modes) with different momenta are created by the first Kapitza-Dirac pulse. These modes are coherently recombined by the harmonic potential with atomic interactions. The second Kapitza-Dirac pulse splits the evolved modes a second time and separates them along different paths for a second time. The signal to noise ratio is numerically calculated by the Fisher information and the Cramér-Rao lower bound. We find that the small atomic interactions decrease the measurement accuracy for current atom interferometers when measuring the gravitational acceleration. Its impact on measurement precision can be reduced by improving the Kapitza-Dirac strength.

  16. Dual atomic interferometer with a tunable point of minimum magnetic sensitivity

    CERN Document Server

    Hamzeloui, Saeed; Abediyeh, Vahideh; Arias, Nieves; Gomez, Eduardo; Valenzuela, Víctor Manuel

    2016-01-01

    Atomic interferometers are often affected by magnetic field fluctuations. Using the clock transition at zero magnetic field minimizes the effect of these fluctuations. There is another transition in rubidium that minimizes the magnetic sensitivity at 3.2 G.We combine the previous two transitions to obtain minimum magnetic sensitivity at a tunable magnetic field between 2.2 and 3.2 G. The two interferometers evolve independently from each other and we control the magnetic sensitivity by changing the population in both transitions with a microwave pulse.

  17. High sensitivity, low-systematics atom interferometers using Bragg diffraction and Bloch oscillations

    CERN Document Server

    Estey, Brian; Müller, Holger; Kuan, Pei-Chen; Lan, Shau-Yu

    2014-01-01

    We describe a new scheme for atom interferometry based on both large-momentum transfer Bragg beam splitters and Bloch oscillations. Combining the advantages of previous approaches to recoil-sensitive interferometers, we increase the signal and suppress a systematic phase shift caused by Bragg diffraction at least 60-fold, matching experiment to theory; the systematic shift can be eliminated from Mach-Zehnder interferometers. We demonstrate high contrast, interference with up to 4.4 million radians of phase difference between freely evolving matter waves, and a resolution of $\\delta \\alpha/\\alpha=0.33\\,$ppb$\\sqrt{\\rm 6h}$ available to measurements of the fine structure constant.

  18. High-Flux Ultracold-Atom Chip Interferometers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ColdQuanta's ultimate objective is to produce a compact, turnkey, ultracold-atom system specifically designed for performing interferometry with Bose-Einstein...

  19. Does an atom interferometer test the gravitational redshift at the Compton frequency ?

    CERN Document Server

    Wolf, Peter; Bordé, Christian J; Cohen-Tannoudji, Claude; Salomon, Christophe; Reynaud, Serge

    2010-01-01

    Atom interferometers allow the measurement of the acceleration of freely falling atoms with respect to an experimental platform at rest on Earth's surface. Such experiments have been used to test the universality of free fall by comparing the acceleration of the atoms to that of a classical freely falling object. In a recent paper, M\\"uller, Peters and Chu [Nature {\\bf 463}, 926-929 (2010)] argued that atom interferometers also provide a very accurate test of the gravitational redshift when considering the atom as a clock operating at the Compton frequency associated with the rest mass. We analyze this claim in the frame of general relativity and of different alternative theories. We show that the difference of "Compton phases" between the two paths of the interferometer is actually zero in a large class of theories, including general relativity, all metric theories of gravity, most non-metric theories and most theoretical frameworks used to interpret the violations of the equivalence principle. Therefore, in...

  20. A high-flux BEC source for mobile atom interferometers

    CERN Document Server

    Rudolph, Jan; Grzeschik, Christoph; Sternke, Tammo; Grote, Alexander; Popp, Manuel; Becker, Dennis; Müntinga, Hauke; Ahlers, Holger; Peters, Achim; Lämmerzahl, Claus; Sengstock, Klaus; Gaaloul, Naceur; Ertmer, Wolfgang; Rasel, Ernst M

    2015-01-01

    Quantum sensors based on coherent matter-waves are precise measurement devices whose ultimate accuracy is achieved with Bose-Einstein condensates (BEC) in extended free fall. This is ideally realized in microgravity environments such as drop towers, ballistic rockets and space platforms. However, the transition from lab-based BEC machines to robust and mobile sources with comparable performance is a technological challenge. Here we report on the realization of a miniaturized setup, generating a flux of $4 \\times 10^5$ quantum degenerate $^{87}$Rb atoms every 1.6 s. Ensembles of $1 \\times 10^5$ atoms can be produced at a 1 Hz rate. This is achieved by loading a cold atomic beam directly into a multi-layer atom chip that is designed for efficient transfer from laser-cooled to magnetically trapped clouds. The attained flux of degenerate atoms is on par with current lab-based experiments while offering significantly higher repetition rates. The compact and robust design allows for mobile operation in a variety of...

  1. Stability comparison of two absolute gravimeters: optical versus atomic interferometers

    CERN Document Server

    Gillot, Pierre; Landragin, Arnaud; Santos, Franck Pereira Dos; Merlet, Sébastien

    2014-01-01

    We report the direct comparison between the stabilities of two mobile absolute gravimeters of different technology: the LNE-SYRTE Cold Atom Gravimeter and FG5X\\#216 of the Universit\\'e du Luxembourg. These instruments rely on two different principles of operation: atomic and optical interferometry. The comparison took place in the Walferdange Underground Laboratory for Geodynamics in Luxembourg, at the beginning of the last International Comparison of Absolute Gravimeters, ICAG-2013. We analyse a 2h10 duration common measurement, and find that the CAG shows better immunity with respect to changes in the level of vibration noise, as well as a slightly better short term stability.

  2. Reexamining the roles of gravitational and inertial masses in gravimetry with atom interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Unnikrishnan, C.S., E-mail: unni@tifr.res.in [Gravitation Group, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Gillies, G.T., E-mail: gtg@virginia.edu [School of Engineering and Applied Science, University of Virginia, Charlottesville, VA 22904-4746 (United States)

    2012-12-03

    We reassess the true roles of the gravitational charge (mass) and the inertial mass in quantum phases acquired in matter-wave interferometry in a gravitational field. The insights gained allow us to address the question of whether gravimetry with atom interferometers is equivalent to a high precision measurement of the relative gravitational time dilation of two clocks separated in space. In particular we show that the gravitational phase is inversely related to the Compton frequency, invalidating the suggested equivalence to a Compton clock. Clarity of arguments is achieved by comparison to a charged matter-wave interferometer. Though quantum states have a similarity to oscillator clocks through the Planck–Einstein–de Broglie relations, it is shown clearly that the claim of greatly enhanced precision over real atomic clock comparison cannot be maintained.

  3. Rigorous Comparison of Gravimetry Employing Atom Interferometers and the Measurement of Gravitational Time Dilation

    CERN Document Server

    Unnikrishnan, C S

    2011-01-01

    We present a gravitationally rigorous and clear answer, in the negative, to the question whether gravimetry with atom interferometers is equivalent to the the measurement of the relative gravitational time dilation of two clocks separated in space. Though matter and light waves, quantum states and oscillator clocks are quantum synonymous through the Planck-Einstein-de Broglie relations and the equivalence principle, there are crucial differences in the context of tests of gravitation theories.

  4. Engineering an atom-interferometer with modulated light-induced $3 \\pi$ spin-orbit coupling

    CERN Document Server

    Olson, Abraham J; Blasing, David B; Niffenegger, Robert J; Chen, Yong P

    2015-01-01

    We have developed an experimental method to modify the single-particle dispersion using periodic modulation of Raman beams which couple two spin-states of an ultracold atomic gas. The modulation introduces a new coupling between Raman-induced spin-orbit-coupled dressed bands, creating a second generation of dressed-state eigenlevels that feature both a novel 3{\\pi} spin-orbit coupling and a pair of avoided crossings, which is used to realize an atomic interferometer. The spin polarization and energies of these eigenlevels are characterized by studying the transport of a Bose-Einstein condensate in this system, including observing a Stueckelberg interference.

  5. Atomic population distribution in the output ports of cold-atom interferometers with optical splitting and recombination

    CERN Document Server

    Ilo-Okeke, Ebubechukwu O

    2010-01-01

    Cold-atom interferometers with optical splitting and recombination use off-resonant laser beams to split a cloud of Bose-Einstein condensate (BEC) into two clouds that travel along different paths and are then recombined again using optical beams. After the recombination, the BEC in general populates both the cloud at rest and the moving clouds. Measuring relative number of atoms in each of these clouds yields information about the relative phase shift accumulated by the atoms in the two moving clouds during the interferometric cycle. We derive the expression for the probability of finding any given number of atoms in each of the clouds, discuss features of the probability density distribution, analyze its dependence on the relative accumulated phase shift as a function of the strength of the interatomic interactions, and compare our results with experiment.

  6. Competition between Spin Echo and Spin Self-Rephasing in a Trapped Atom Interferometer

    CERN Document Server

    Solaro, Cyrille; Combes, Frédéric; Lopez, Matthias; Alauze, Xavier; Fuchs, Jean-Noël; Piéchon, Frédéric; Santos, Franck Pereira dos

    2016-01-01

    We perform Ramsey interferometry on an ultracold 87Rb ensemble confined in an optical dipole trap. We use a $\\pi$-pulse set at the middle of the interferometer to restore the coherence of the spin ensemble by canceling out phase inhomogeneities and creating a spin echo in the contrast. However, for high atomic densities, we observe the opposite behavior: the $\\pi$-pulse accelerates the dephasing of the spin ensemble leading to a faster contrast decay of the interferometer. We understand this phenomenon as a competition between the spin-echo technique and an exchange-interaction driven spin self-rephasing mechanism based on the identical spin rotation effect (ISRE). Our experimental data is well reproduced by a numerical model.

  7. Testing general relativity and alternative theories of gravity with space-based atomic clocks and atom interferometers

    Directory of Open Access Journals (Sweden)

    Bondarescu Ruxandra

    2015-01-01

    Full Text Available The successful miniaturisation of extremely accurate atomic clocks and atom interferometers invites prospects for satellite missions to perform precision experiments. We discuss the effects predicted by general relativity and alternative theories of gravity that can be detected by a clock, which orbits the Earth. Our experiment relies on the precise tracking of the spacecraft using its observed tick-rate. The spacecraft’s reconstructed four-dimensional trajectory will reveal the nature of gravitational perturbations in Earth’s gravitational field, potentially differentiating between different theories of gravity. This mission can measure multiple relativistic effects all during the course of a single experiment, and constrain the Parametrized Post-Newtonian Parameters around the Earth. A satellite carrying a clock of fractional timing inaccuracy of Δ f / f ∼ 10−16 in an elliptic orbit around the Earth would constrain the PPN parameters |β − 1|, |γ − 1| ≲ 10−6. We also briefly review potential constraints by atom interferometers on scalar tensor theories and in particular on Chameleon and dilaton models.

  8. Longitudinal structure in atomic oxygen concentrations observed with WINDII on UARS. [Wind Imaging Interferometer

    Science.gov (United States)

    Shepherd, G. G.; Thuillier, G.; Solheim, B. H.; Chandra, S.; Cogger, L. L.; Duboin, M. L.; Evans, W. F. J.; Gattinger, R. L.; Gault, W. A.; Herse, M.

    1993-01-01

    WINDII, the Wind Imaging Interferometer on the Upper Atmosphere Research Satellite, began atmospheric observations on September 28, 1991 and since then has been collecting data on winds, temperatures and emissions rates from atomic, molecular and ionized oxygen species, as well as hydroxyl. The validation of winds and temperatures is not yet complete, and scientific interpretation has barely begun, but the dominant characteristic of these data so far is the remarkable structure in the emission rate from the excited species produced by the recombination of atomic oxygen. The latitudinal and temporal variability has been noted before by many others. In this preliminary report on WINDII results we draw attention to the dramatic longitudinal variations of planetary wave character in atomic oxygen concentration, as reflected in the OI 557.7 nm emission, and to similar variations seen in the Meine1 hydroxyl band emission.

  9. Testing the Universality of Free Fall with a Dual-Species Atom Interferometer on Ste-Quest

    Science.gov (United States)

    Krutzik, Markus; Peters, Achim

    2014-01-01

    The Space-Time Explorer and Quantum Equivalence Space Test (STEQUEST) satellite mission is devoted to testing several aspects of General Relativity using an atomic clock and a differential dual-species atom interferometer in space. The latter aims at performing a quantum test of the Einstein equivalence principle in the perigee phase of a highly elliptical Earth orbit by probing the universality of free fall with coherent matter waves. In this paper, we give a brief summary on the mission and the prospects for the dual-species atom interferometer.

  10. Frequency-doubled telecom fiber laser for a cold atom interferometer using optical lattices

    Science.gov (United States)

    Theron, Fabien; Bidel, Yannick; Dieu, Emily; Zahzam, Nassim; Cadoret, Malo; Bresson, Alexandre

    2017-06-01

    A compact and robust frequency-doubled telecom laser system at 780 nm is presented for a rubidium cold atom interferometer using optical lattices. Adopting an optical switch at 1.5 μm and a dual-wavelength second harmonic generation system, only one laser amplifier is required for the laser system. Our system delivers a 900 mW laser beam with a detuning of 110 GHz for the optical lattice and a 650 mW laser beam with an adjustable detuning between 0 and -1 GHz for the laser cooling, the detection and the Raman transitions.

  11. Frequency doubled telecom fiber laser for a cold atom interferometer using optical lattices

    CERN Document Server

    Theron, Fabien; Dieu, Emily; Zahzam, Nassim; Cadoret, Malo; Zahzam, Nassim; Bresson, Alexandre

    2016-01-01

    A compact and robust laser system, based on a frequency-doubled telecom laser, providing all the lasers needed for a rubidium cold atom interferometer using optical lattices is presented. Thanks to an optical switch at 1.5 \\mu m and a dual-wavelength second harmonic generation system, only one laser amplifier is needed for all the laser system. Our system delivers at 780 nm a power of 900 mW with a detuning of 110 GHz for the optical lattice and a power of 650 mW with an adjustable detuning between 0 and -1 GHz for the laser cooling, the detection and the Raman transitions.

  12. Testing General Relativity and Alternative Theories of Gravity with Space-based Atomic Clocks and Atom Interferometers

    CERN Document Server

    Bondarescu, Ruxandra; Jetzer, Philippe; Angélil, Raymond; Saha, Prasenjit; Lundgren, Andrew

    2015-01-01

    The successful miniaturisation of extremely accurate atomic clocks and atom interferometers invites prospects for satellite missions to perform precision experiments. We discuss the effects predicted by general relativity and alternative theories of gravity that can be detected by a clock, which orbits the Earth. Our experiment relies on the precise tracking of the spacecraft using its observed tick-rate. The spacecraft's reconstructed four-dimensional trajectory will reveal the nature of gravitational perturbations in Earth's gravitational field, potentially differentiating between different theories of gravity. This mission can measure multiple relativistic effects all during the course of a single experiment, and constrain the Parametrized Post-Newtonian Parameters around the Earth. A satellite carrying a clock of fractional timing inaccuracy of $\\Delta f/f \\sim 10^{-16}$ in an elliptic orbit around the Earth would constrain the PPN parameters $|\\beta -1|, |\\gamma-1| \\lesssim 10^{-6}$. We also briefly revi...

  13. Demonstration of a Tunable-Bandwidth White Light Interferometer using Anomalous Dispersion in Atomic Vapor

    CERN Document Server

    Pati, G S; Salit, M; Shahriar, M S

    2006-01-01

    The concept of the 'white-light cavity' has recently generated considerable research interest in the context of gravitational wave detection. Cavity designs are proposed using negative (or anomalous) dispersion in an intracavity medium to make the cavity resonate over a large range of frequencies and still maintain a high cavity build-up. This paper presents the first experimental attempt and demonstration of white-light effect in a meter long ring cavity using an intracavity atomic medium. The medium's negative dispersion is caused by bi-frequency Raman gain in an atomic vapor cell. Although the white light condition was not perfectly achieved and improvements in experimental control are still desirable, significantly broad cavity response over bandwidth greater than 20 MHz has been observed. These devices will have potential applications in new generation laser interferometer gravitational wave detectors.

  14. Contrast and phase-shift of a trapped atom interferometer using a thermal ensemble with internal state labelling

    CERN Document Server

    Dupont-Nivet, M; Schwartz, S

    2016-01-01

    We report a theoretical study of a double-well Ramsey interferometer using internal state labelling. We consider the use of a thermal ensemble of cold atoms rather than a Bose-Einstein condensate to minimize the effects of atomic interactions. To maintain a satisfactory level of coherence in this case, a high degree of symmetry is required between the two arms of the interferometer. Assuming that the splitting and recombination processes are adiabatic, we theoretically derive the phase-shift and the contrast of such an interferometer in the presence of gravity or an acceleration field. We also consider using a "shortcut to adiabaticity" protocol to speed up the splitting process and discuss how such a procedure affects the phase shift and contrast. We find that the two procedures lead to phase-shifts of the same form.

  15. Generalized Collective States and Their Role in a Collective State Atomic Interferometer and Atomic Clock

    CERN Document Server

    Sarkar, Resham; Fang, Renpeng; Tu, Yanfei; Shahriar, Selim M

    2014-01-01

    We investigate the behavior of an ensemble of N non-interacting, identical atoms, excited by a laser with a wavelength of $\\lambda$. In general, the i-th atom sees a Rabi frequency $\\Omega_i$, an initial position dependent laser phase $\\phi_i$, and a motion induced Doppler shift of $\\delta_i$. When $\\Omega_i=\\Omega$ and $\\delta_i=\\delta$ for all atoms, the system evolves into a superposition of (N+1) symmetric collective states (SCS), independent of the values of $\\phi_i$. If $\\phi_i=\\phi$ for all atoms, these states simplify to the well-known Dicke collective states. When $\\Omega_i$ or $\\delta_i$ is distinct for each atom, the system evolves into a superposition of SCS as well as asymmetric collective states (ACS). For large N, the number of ACS's $(2^N-N-1)$ is far greater than that of the SCS. We show how to formulate the properties of all the collective states under various non-idealities, and use this formulation to understand the dynamics thereof. For the case where $\\Omega_i=\\Omega$ and $\\delta_i=\\delt...

  16. Studying fluctuations of the local gravity field with an array of atom interferometers

    Science.gov (United States)

    Pelisson, Sophie; Bertoldi, Andrea; Canuel, Benjamin; Lefèvre, Grégoire; Riou, Isabelle; Bouyer, Philippe

    2016-04-01

    The Matter wave-laser Interferometer Gravitational Antenna (MIGA) project concerns the construction of a novel infrastructure to study strain tensor of space-time and gravitation. Using the great progresses made in last years on atom interferometry, the project aims to develop a novel approach for strain measurement and to develop a better understanding of the earth's gravity field over a broad band from frequencies of 1mHz to 10Hz. The applications of MIGA will extend from monitoring the evolution of the gravitational field to providing a new tool for detecting gravitational waves. Here we will present the basics of the instruments and the principles on which the measurement will lay. In a second time, we will explore more carefully the kind of signal that the instrument will detect and the methods to discriminate geophysical signals from gravitational waves ones.

  17. Contribution to the theory of atom interferometers; Contribution a la theorie des interferometres atomiques

    Energy Technology Data Exchange (ETDEWEB)

    Antoine, Ch

    2004-12-01

    This work deals with the study of atom interferometers. It consists of theoretical developments and more practical parts (modeling). As regards modeling, this work explains how to obtain a general analytical expression of the fringes signal, which particularly accounts for the simultaneous action of all the inertial and gravitational fields whose representative potential is at most quadratic in position and momentum (rotations, accelerations, gradients of acceleration, gravitational waves...), as well as the dispersive structuring due to atomic beam splitters in the presence of such external fields (velocity selection, anomalous dispersion and Borrmann effect). From a theoretical point of view, this thesis develops new tools of atom optics. They deal with the propagation of matter waves in unspecified inertial and gravitational fields (extension of the ABCD formalism using first integral operators), the study of laser beam splitters in the presence of some of these fields (generalized ttt scheme, strong fields ttt modeling, generalized Borrmann effect...), as well as the highlight of symplectic invariants which are very useful for the interpretation and the simplification of the phase shift expression ('homologous paths' and 'four end points theorem'). (author)

  18. Rapid extraction of the phase shift of the cold-atom interferometer via phase demodulation

    Institute of Scientific and Technical Information of China (English)

    程冰; 王兆英; 许翱鹏; 王启宇; 林强

    2015-01-01

    Generally, the phase of the cold-atom interferometer is extracted from the atomic interference fringe, which can be obtained by scanning the chirp rate of the Raman lasers at a given interrogation time T . If mapping the phase shift for each T with a series of measurements, the extraction time is limited by the protocol of each T measurement, and therefore increases dramatically when doing fine mapping with a small step of T . Here we present a new method for rapid extraction of the phase shift via phase demodulation. By using this method, the systematic shifts can be mapped though the whole interference area. This method enables quick diagnostics of the potential cause of the phase shift in specific time. We demonstrate experimentally that this method is effective for the evaluation of the systematic errors of the cold atomic gravimeter. The systematic phase error induced by the quadratic Zeeman effect in the free-falling region is extracted by this method. The measured results correspond well with the theoretic prediction and also agree with the results obtained by the fringe fitting method for each T .

  19. Low Frequency Gravitational Wave Detection With Ground Based Atom Interferometer Arrays

    CERN Document Server

    Chaibi, W; Canuel, B; Bertoldi, A; Landragin, A; Bouyer, P

    2016-01-01

    We propose a new detection strategy for gravitational waves (GWs) below few Hertz based on a correlated array of atom interferometers (AIs). Our proposal allows to reduce the Newtonian Noise (NN) which limits all ground based GW detectors below few Hertz, including previous atom interferometry-based concepts. Using an array of long baseline AI gradiometers yields several estimations of the NN, whose effect can thus be reduced via statistical averaging. Considering the km baseline of current optical detectors, a NN rejection of factor 2 could be achieved, and tested with existing AI array geometries. Exploiting the correlation properties of the gravity acceleration noise, we show that a 10-fold or more NN rejection is possible with a dedicated configuration. Considering a conservative NN model and the current developments in cold atom technology, we show that strain sensitivities below $1\\times 10^{-19}/ \\sqrt{\\text{Hz}}$ in the $ 0.3-3 \\ \\text{Hz}$ frequency band can be within reach, with a peak sensitivity o...

  20. Reply to the comment on: "Does an atom interferometer test the gravitational redshift at the Compton frequency?"

    CERN Document Server

    Wolf, Peter; Bordé, Christian J; Reynaud, Serge; Salomon, Christophe; Cohen-Tannoudji, Claude

    2012-01-01

    Hohensee, Chu, Peters and M\\"uller have submitted a comment (arXiv:1112.6039 [gr-qc]) on our paper "Does an atom interferometer test the gravitational redshift at the Compton frequency?", Classical and Quantum Gravity 28, 145017 (2011), arXiv:1009.2485 [gr-qc]. Here we reply to this comment and show that the main result of our paper, namely that atom interferometric gravimeters do not test the gravitational redshift at the Compton frequency, remains valid.

  1. Matter-wave beam splitter on an atom chip for a portable atom-interferometer

    CERN Document Server

    Kim, S J; Gang, S T; Kim, J B

    2016-01-01

    We construct a matter-wave beam splitter using 87Rb Bose-Einstein condensate on an atom chip. Through the use of radio-frequency-induced double-well potentials, we were able to split a BEC into two clouds separated by distances ranging from 2.8 {\\mu}m to 57 {\\mu}m. Interference between these two freely expanding BECs has been observed. By varying the rf-field amplitude, frequency, or polarization, we investigate behaviors of the beam-splitter. From the perspective of practical use, our BEC manipulation system is suitable for application to interferometry since it is compact and the repetition rate is high due to the anodic bonded atom chip on the vacuum cell. The portable system occupies a volume of 0.5 m3 and operates at a repetition rate as high as ~0.2 Hz.

  2. Matter-wave beam splitter on an atom chip for a portable atom interferometer

    Science.gov (United States)

    Kim, S. J.; Yu, H.; Gang, S. T.; Kim, J. B.

    2017-05-01

    We constructed a matter-wave beam splitter on an atom chip using a 87Rb Bose-Einstein condensate. Using radio-frequency-induced double-well potentials, we were able to coherently split a BEC into two clouds separated by distances ranging from 2.8 to 57 μm. Interference between these two freely expanding BECs was observed, confirming the coherence of the matter-wave beam splitter. We are able to control the distance and the angle between the split BECs by varying the rf-field's amplitude, frequency, or polarization. From the perspective of practical use, our BEC manipulation system is suitable for application to interferometry. It is compact, and by anodic bonding the atom chip to the vacuum cell, the repetition rate is kept high. The portable system occupies a volume of 0.5 m3 and operates at a repetition rate as high as 0.2 Hz using a commercial vacuum product.

  3. Fringe-locking method for the weak equivalence principle test by simultaneous dual-species atom interferometers

    CERN Document Server

    Duan, Xiao-Chun; Mao, De-Kai; Zhou, Min-Kang; Shao, Cheng-Gang; Hu, Zhong-Kun

    2016-01-01

    We theoretically investigate the application of the fringe-locking method (FLM) in the dual-species quantum test of the weak equivalence principle (WEP). With the FLM, the measurement is performed invariably at the midfringe, and the extraction of the phase shift for atom interferometers is linearized. For the simultaneous interferometers, this linearization enables a good common-mode rejection of vibration noise, which is usually the main limit for high precision WEP tests of dual-species kind. We note that this method also allows for an unbiased determination of the gravity accelerations difference, which meanwhile is readily to be implemented.

  4. A low noise all-fiber interferometer for high resolution frequency modulated atomic force microscopy imaging in liquids.

    Science.gov (United States)

    Rasool, Haider I; Wilkinson, Paul R; Stieg, Adam Z; Gimzewski, James K

    2010-02-01

    We have developed a low noise all-fiber interferometer for use as the deflection sensor in liquid environment frequency modulated atomic force microscopy (FM-AFM). A detailed description and rationale for the choice of the critical components are provided along with the design of a simple alignment assembly. The optimization of the deflection sensor toward achieving the highest possible sensitivity and lowest deflection noise density is discussed in the context of an ideal interference cavity. Based on the provided analysis we have achieved deflection noise densities of 2 fm/square root(Hz) on commercially available cantilevers in both ambient and liquid environments. The low noise interferometer works without the need for differential detection, special focusing lenses, or polarization sensitive optics, dramatically simplifying measurements. True atomic resolution imaging of muscovite mica by FM-AFM in water is demonstrated using the developed deflection sensor.

  5. Evolution of the wave function of an atom hit by a photon in a three-grating interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Arsenovic, Dusan; Bozic, Mirjana [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia); Sanz, Angel S [Instituto de Fisica Fundamental, Consejo Superior de Investigaciones CientIficas, Serrano 123, 28006 Madrid (Spain); Davidovic, Milena [Faculty of Civil Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Belgrade (Serbia)], E-mail: arsenovic@phy.bg.ac.yu, E-mail: bozic@phy.bg.ac.yu, E-mail: asanz@imaff.cfmac.csic.es, E-mail: milena@grf.bg.ac.yu

    2009-07-15

    In 1995, Chapman et al (1995 Phys. Rev. Lett. 75 2783) showed experimentally that the interference contrast in a three-grating atom interferometer does not vanish in the presence of scattering events with photons, as required by the complementarity principle. In this work, we present an analytical study of this experiment by determining the evolution of an atom's wave function along the three-grating Mach-Zehnder interferometer under the assumption that the atom is hit by a photon after passing through the first grating. The consideration of a transverse wave function in momentum representation is essential in this study. As is shown, the number of atoms transmitted through the third grating is given by a simple periodic function of the lateral shift along this grating, both in the absence and in the presence of photon scattering. Moreover, the relative contrast (laser on/laser off) is shown to be a simple analytical function of the ratio d{sub p}/{lambda}{sub i}, where d{sub p} is the distance between atomic paths at the scattering locus and {lambda} {sub i} the scattered photon wavelength. We argue that this dependence, being in agreement with experimental results, can be considered as showing compatibility between the wave and corpuscle properties of atoms.

  6. A double-interferometer laser system for cold 87Rb atom gyroscopes based on stimulated Raman transitions

    CERN Document Server

    Song, Ningfang; Li, Wei; Li, Yang; Liu, Jixun; Xu, Xiaobin; Pan, Xiong

    2014-01-01

    We proposed and implemented a double-interferometer laser system to manipulate cold 87Rb atoms to interfere. A frequency-modulated continuous-wave technique was applied to determine and compensate the optical path difference between the two Raman beams. With a coherent self-heterodyne method, the beat signal's FWHM linewidth was measured and the obtained linewidth of ~1Hz mainly limited by the resolution bandwidth of the spectrum analyzer indicates a good coherence degree of the two Raman beams, paving the way to realize a highly sensitive atom gyroscope.

  7. Atomic-resolution measurements with a new tunable diode laser-based interferometer

    DEFF Research Database (Denmark)

    Silver, R.M.; Zou, H.; Gonda, S.;

    2004-01-01

    We develop a new implementation of a Michelson interferometer designed to make measurements with an uncertainty of less than 20 pm. This new method uses a tunable diode laser as the light source, with the diode laser wavelength continuously tuned to fix the number of fringes in the measured optical...... laser Michelson interferometer....... path. The diode laser frequency is measured by beating against a reference laser. High-speed, accurate frequency measurements of the beat frequency signal enables the diode laser wavelength to be measured with nominally 20-pm accuracy for the measurements described. The new interferometer design...

  8. Atom interferometry with lithium atoms: theoretical analysis and design of an interferometer, applications; Interferometrie atomique avec l'atome de lithium: analyse theorique et construction d'un interferometre, applications

    Energy Technology Data Exchange (ETDEWEB)

    Champenois, C

    1999-12-01

    This thesis is devoted to studies which prepared the construction of an atom Mach-Zehnder interferometer. In such an interferometer, the propagating waves are spatially separated, and the internal state of the atom is not modified. The beam-splitters are diffraction gratings, consisting of standing optical waves near-resonant with an atomic transition. We use the Bloch functions to define the atom wave inside the standing wave grating and thus explain the diffraction process in different cases. We developed a nearly all-analytical model for the propagation of an atom wave inside a Mach-Zehnder interferometer. The contrast of the signal is studied for many cases: phase or amplitude gratings, effects of extra paths, effects of the main mismatches, monochromatic or lightly polychromatic sources. Finally, we discuss three interferometric measurements we think very interesting. The first, the index of refraction of gas for atomic waves, is studied in detail, with numerical simulations. The other measures we propose deal with the electrical properties of lithium. We discuss the ultimate limit for the measure of the static electric polarizability of lithium by atomic interferometry. Then, we discuss how one could measure the possible charge of the lithium atom. We conclude that an optically cooled and collimated atom beam would improve precision. (author)

  9. Test of Equivalence Principle at 10(-8) Level by a Dual-Species Double-Diffraction Raman Atom Interferometer.

    Science.gov (United States)

    Zhou, Lin; Long, Shitong; Tang, Biao; Chen, Xi; Gao, Fen; Peng, Wencui; Duan, Weitao; Zhong, Jiaqi; Xiong, Zongyuan; Wang, Jin; Zhang, Yuanzhong; Zhan, Mingsheng

    2015-07-01

    We report an improved test of the weak equivalence principle by using a simultaneous 85Rb-87Rb dual-species atom interferometer. We propose and implement a four-wave double-diffraction Raman transition scheme for the interferometer, and demonstrate its ability in suppressing common-mode phase noise of Raman lasers after their frequencies and intensity ratios are optimized. The statistical uncertainty of the experimental data for Eötvös parameter η is 0.8×10(-8) at 3200 s. With various systematic errors corrected, the final value is η=(2.8±3.0)×10(-8). The major uncertainty is attributed to the Coriolis effect.

  10. Test of Equivalence Principle at $10^{-8}$ Level by a Dual-species Double-diffraction Raman Atom Interferometer

    CERN Document Server

    Zhou, Lin; Tang, Biao; Chen, Xi; Gao, Fen; Peng, Wencui; Duan, Weitao; Zhong, Jiaqi; Xiong, Zongyuan; Wang, Jin; Zhang, Yuanzhong; Zhan, Mingsheng

    2015-01-01

    We report an improved test of the weak equivalence principle by using a simultaneous $^{85}$Rb-$^{87}$Rb dual-species atom interferometer. We propose and implement a four-wave double-diffraction Raman transition scheme for the interferometer, and demonstrate its ability in suppressing common-mode phase noise of Raman lasers after their frequencies and intensity ratios are optimized. The statistical uncertainty of the experimental data for E\\"{o}tv\\"{o}s parameter $\\eta$ is $0.8\\times10^{-8}$ at 3200 s. With various systematic errors corrected the final value is $\\eta=(2.8\\pm3.0)\\times10^{-8}$. The major uncertainty is attributed to the Coriolis effect.

  11. Characterization of a Simultaneous Dual-Species Atom Interferometer for a Quantum Test of the Weak Equivalence Principle

    CERN Document Server

    Bonnin, A; Bidel, Y; Bresson, A

    2015-01-01

    We present here the performance of a simultaneous dual-species matter-wave accelerometer for measuring the differential acceleration between two different atomic species ($^{87}$Rb and $^{85}$Rb). We study the expression and the extraction of the differential phase from the interferometer output. The differential accelerometer reaches a short-term sensitivity of $1.23\\times10^{-7}g/\\sqrt{Hz}$ limited by the detection noise and a resolution of $2\\times10^{-9}g$ after 11000 s, the highest reported thus far with a dual-species atom interferometer to our knowledge. Thanks to the simultaneous measurement, such resolution levels can still be achieved even with vibration levels up to $3\\times10^{-3}g$, corresponding to a common-mode vibration noise rejection ratio of 94 dB (rejection factor of 50 000). These results prove the ability of such atom sensors for realizing a quantum based test of the weak equivalence principle (WEP) at a level of $\\eta\\sim10^{-9}$ even with high vibration levels and a compact sensor.

  12. Statistical analysis of thermospheric gravity waves from Fabry-Perot Interferometer measurements of atomic oxygen

    Directory of Open Access Journals (Sweden)

    E. A. K. Ford

    2008-02-01

    Full Text Available Data from the Fabry-Perot Interferometers at KEOPS (Sweden, Sodankylä (Finland, and Svalbard (Norway, have been analysed for gravity wave activity on all the clear nights from 2000 to 2006. A total of 249 nights were available from KEOPS, 133 from Sodankylä and 185 from the Svalbard FPI. A Lomb-Scargle analysis was performed on each of these nights to identify the periods of any wave activity during the night. Comparisons between many nights of data allow the general characteristics of the waves that are present in the high latitude upper thermosphere to be determined. Comparisons were made between the different parameters: the atomic oxygen intensities, the thermospheric winds and temperatures, and for each parameter the distribution of frequencies of the waves was determined. No dependence on the number of waves on geomagnetic activity levels, or position in the solar cycle, was found. All the FPIs have had different detectors at various times, producing different time resolutions of the data, so comparisons between the different years, and between data from different sites, showed how the time resolution determines which waves are observed. In addition to the cutoff due to the Nyquist frequency, poor resolution observations significantly reduce the number of short-period waves (<1 h period that may be detected with confidence. The length of the dataset, which is usually determined by the length of the night, was the main factor influencing the number of long period waves (>5 h detected. Comparisons between the number of gravity waves detected at KEOPS and Sodankylä over all the seasons showed a similar proportion of waves to the number of nights used for both sites, as expected since the two sites are at similar latitudes and therefore locations with respect to the auroral oval, confirming this as a likely source region. Svalbard showed fewer waves with short periods than KEOPS data for a season when both had the same time resolution data

  13. Towards a Test of the Equivalence Principle With a Two-species Atom Interferometer Operating in Micro Gravity

    Science.gov (United States)

    Geiger, Remi; Menoret, Vincent; Cheinet, Patrick; Bouyer, Philippe; Stern, Guillaume; Landragin, Arnaud; Zahzam, Nassim; Bresson, Alexandre

    Our work aims at developing an atom accelerometer using two different species (87 Rb and 39 K) and operating in a plane which carries out parabolic flights. The physical process underlying the operation of our instrument is a matter waves interferometer [1,2] using bosonic atoms which are laser cooled down to temperatures of the order of the micro Kelvin. In the quest for testing the weak equivalence principle with these two atomic species as test masses, we have proposed an analysis to estimate their differential acceleration [3]. In particular, we have shown that we could reject a significant part of the acceleration noise in the plane. Since the two atoms move with respect to the same reference frame (a mirror), they share a common source of acceleration noise. Its impact can be reduced thanks to an appropriate choice of the scale factors of each interferometer. Therefore, we intend to measure the relative differential acceleration of the two species in free fall with the 0g-plane with a short term stability comparable to the state of the art. Experimentally, we have demonstrated our ability to perform sensitive interferometric measure-ments during the weightlessness phases on board of the A300-0g Airbus of CNES [4]. Recently, we have investigated the sensitivity of the 87 Rb-interferometer to inertial effects such as accel-erations, when our setup operates in this plane [5]. Such measurements rely on a correlation between the atomic interferences signal and classical accelerometers fixed on the mirror refer-encing the motion of the atoms. We will use this method to further reject an important amount of the acceleration noise in the reference frame. Meanwhile, we have developed original lasers sources for cooling and manipulating 87 Rb and 39 K atoms. The full laser design of our experiment is based on telecom technologies and fiber optics which results in a robust, compact and transportable setup [6]. These technical efforts have been realized in the context of

  14. Testing the universality of free fall with rubidium and ytterbium in a very large baseline atom interferometer

    CERN Document Server

    Hartwig, Jonas; Schubert, Christian; Schlippert, Dennis; Ahlers, Holger; Posso-Trujillo, Katerine; Gaaloul, Naceur; Ertmer, Wolfgang; Rasel, Ernst M

    2015-01-01

    We propose a very long baseline atom interferometer test of Einstein's equivalence principle (EEP) with ytterbium and rubidium extending over 10m of free fall. In view of existing parametrizations of EEP violations, this choice of test masses significantly broadens the scope of atom interferometric EEP tests with respect to other performed or proposed tests by comparing two elements with high atomic numbers. In a first step, our experimental scheme will allow reaching an accuracy in the E\\"otv\\"os ratio of $7\\times 10^{-13}$. This achievement will constrain violation scenarios beyond our present knowledge and will represent an important milestone for exploring a variety of schemes for further improvements of the tests as outlined in the paper. We will discuss the technical realisation in the new infrastructure of the Hanover Institute of Technology (HITec) and give a short overview of the requirements to reach this accuracy. The experiment will demonstrate a variety of techniques which will be employed in fut...

  15. Mechanical and Thermal Design and Qualification of an Atom Interferometer Sounding Rocket Payload

    Science.gov (United States)

    Grosse, J.; Seidel, S. T.; Krutzik, M.; Wendrich, T.; Stamminger, A.; Scharringhausen, M.; Quantus Consortium

    2015-09-01

    The MAIUS-1 experiment is a pathfinder quantum optics experiment about to fly on a VSB-30 sounding rocket in November 2015. The scientific objective of the mission is to demonstrate the feasibility of creating a Bose-Einstein Condensate and performing atom interferometry aboard a sounding rocket with Rubidium 87atoms. This paper will summarize the thermal and mechanical design of the payload and its (sub)systems. Moreover the qualification procedures and the results of the qualification test will be presented.

  16. Schrodinger Cat State Atomic Interferometer with Heisenberg-Limited Sensitivity and Detection of Collective States

    Science.gov (United States)

    Sarkar, Resham

    In this thesis, we show first how to formulate the properties of all the collective states under various non-idealities, and use this formulation to understand the dynamics thereof. We show that the collective states corresponding to the absorption of a given number of photons can be visualized as an abstract, multi-dimensional rotation in the Hilbert space spanned by the ordered product states of individual atoms. We also consider the effect of treating the center of mass degree of freedom of the atoms quantum mechanically on the description of the collective states. In particular, we show that it is indeed possible to construct a generalized collective state, as needed for the COSAIN, when each atom is assumed to be in a localized wave packet. (Abstract shortened by ProQuest.).

  17. High time resolution measurements of the thermosphere from Fabry-Perot Interferometer measurements of atomic oxygen

    Directory of Open Access Journals (Sweden)

    E. A. K. Ford

    2007-06-01

    Full Text Available Recent advances in the performance of CCD detectors have enabled a high time resolution study of the high latitude upper thermosphere with Fabry-Perot Interferometers (FPIs to be performed. 10-s integration times were used during a campaign in April 2004 on an FPI located in northern Sweden in the auroral oval. The FPI is used to study the thermosphere by measuring the oxygen red line emission at 630.0 nm, which emits at an altitude of approximately 240 km. Previous time resolutions have been 4 min at best, due to the cycle of look directions normally observed. By using 10 s rather than 40 s integration times, and by limiting the number of full cycles in a night, high resolution measurements down to 15 s were achievable. This has allowed the maximum variability of the thermospheric winds and temperatures, and 630.0 nm emission intensities, at approximately 240 km, to be determined as a few minutes. This is a significantly greater variability than the often assumed value of 1 h or more. A Lomb-Scargle analysis of this data has shown evidence of gravity wave activity with waves with short periods. Gravity waves are an important feature of mesosphere-lower thermosphere (MLT dynamics, observed using many techniques and providing an important mechanism for energy transfer between atmospheric regions. At high latitudes gravity waves may be generated in-situ by localised auroral activity. Short period waves were detected in all four clear nights when this experiment was performed, in 630.0 nm intensities and thermospheric winds and temperatures. Waves with many periodicities were observed, from periods of several hours, down to 14 min. These waves were seen in all parameters over several nights, implying that this variability is a typical property of the thermosphere.

  18. Note: Directly measuring the direct digital synthesizer frequency chirp-rate for an atom interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Juan-Juan; Zhou, Min-Kang, E-mail: zkhu@hust.edu.cn, E-mail: zmk@hust.edu.cn; Zhang, Qiao-Zhen; Cui, Jia-Feng; Duan, Xiao-Chun; Shao, Cheng-Gang; Hu, Zhong-Kun, E-mail: zkhu@hust.edu.cn, E-mail: zmk@hust.edu.cn [MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074 (China)

    2015-09-15

    During gravity measurements with Raman type atom interferometry, the frequency of the laser used to drive Raman transition is scanned by chirping the frequency of a direct digital synthesizer (DDS), and the local gravity is determined by precisely measuring the chip rate α of DDS. We present an effective method that can directly evaluate the frequency chirp rate stability of our DDS. By mixing a pair of synchronous linear sweeping signals, the chirp rate fluctuation is precisely measured with a frequency counter. The measurement result shows that the relative α instability can reach 5.7 × 10{sup −11} in 1 s, which is neglectable in a 10{sup −9} g level atom interferometry gravimeter.

  19. A precision analysis and determination of the technical requirements of an atom interferometer for gravity measurement

    Institute of Scientific and Technical Information of China (English)

    Zhao-ying WANG; Tao CHEN; Xiao-long WANG; Zhang ZHANG; Yun-fei XU; Qiang LIN

    2009-01-01

    The influence of the wave-front curvature of Raman pulses on the measurement precision of gravitational acceleration in atom interferometry is analysed by the method of a transmission matrix. It is shown that the measurement precision of gravitational acceleration is largely dependent on the spot size of the Raman pulse, the temporal interval between Raman pulses and the optical path difference of the two counter-propagating Raman pulses. Moreover, the influence of Doppler frequency shift on the precision is discussed. In order to get a certain measurement precision, the requirement for the accuracy of frequency scanning of the Raman pulse to compensate for the Doppler frequency shift is obtained.

  20. Test of Equivalence Principle at 1 0-8 Level by a Dual-Species Double-Diffraction Raman Atom Interferometer

    Science.gov (United States)

    Zhou, Lin; Long, Shitong; Tang, Biao; Chen, Xi; Gao, Fen; Peng, Wencui; Duan, Weitao; Zhong, Jiaqi; Xiong, Zongyuan; Wang, Jin; Zhang, Yuanzhong; Zhan, Mingsheng

    2015-07-01

    We report an improved test of the weak equivalence principle by using a simultaneous 85Rb-87Rb dual-species atom interferometer. We propose and implement a four-wave double-diffraction Raman transition scheme for the interferometer, and demonstrate its ability in suppressing common-mode phase noise of Raman lasers after their frequencies and intensity ratios are optimized. The statistical uncertainty of the experimental data for Eötvös parameter η is 0.8 ×1 0-8 at 3200 s. With various systematic errors corrected, the final value is η =(2.8 ±3.0 )×1 0-8. The major uncertainty is attributed to the Coriolis effect.

  1. Effects of non-idealities and quantization of the center of mass motion on symmetric and asymmetric collective states in a collective state atomic interferometer

    Science.gov (United States)

    Sarkar, Resham; Kim, May E.; Fang, Renpeng; Tu, Yanfei; Shahriar, Selim M.

    2015-09-01

    We investigate the behavior of an ensemble of ? non-interacting, identical atoms excited by a laser. In general, the ?-th atom sees a Rabi frequency ?, an initial position dependent laser phase ?, and a motion induced Doppler shift of ?. When ? or ? is distinct for each atom, the system evolves into a superposition of ? intercoupled states, of which there are ? symmetric and ? asymmetric collective states. For a collective state atomic interferometer (COSAIN), we recently proposed, it is important to understand the behavior of all the collective states under various conditions. In this paper, we show how to formulate the properties of these states under various non-idealities, and use this formulation to understand the dynamics thereof. We also consider the effect of treating the center of mass degree of freedom of the atoms quantum mechanically on the description of the collective states, illustrating that it is indeed possible to construct a generalized collective state, as needed for the COSAIN, when each atom is assumed to be in a localized wave packet. The analysis presented in this paper is important for understanding the dynamics of the COSAIN, and will help advance the analysis and optimization of spin squeezing in the presence of practically unavoidable non-idealities as well as in the domain where the center of mass motion of the atoms is quantized.

  2. Temporal characterization of short-pulse third-harmonic generation in an atomic gas by a transmission-grating Michelson interferometer.

    Science.gov (United States)

    Papadogiannis, N A; Nersisyan, G; Goulielmakis, E; Rakitzis, T P; Hertz, E; Charalambidis, D; Tsakiris, G D; Witte, K

    2002-09-01

    By use of a transmission-grating-based Michelson interferometer, second-order interferometric as well as intensity autocorrelation traces of the third harmonic of a Ti:sapphire 50-fs laser beam produced in Ar have been measured. The duration of the harmonic is found to be that expected from lowest-order perturbation theory. At this wavelength, the performance of the interferometer with respect to pulse-front distortion and dispersion is found to be satisfactory. This result is a first step toward the use of the interferometer for the temporal characterization of higher harmonics or harmonic superposition forming attosecond pulse trains.

  3. Multimode interferometer for guided matter waves.

    Science.gov (United States)

    Andersson, Erika; Calarco, Tommaso; Folman, Ron; Andersson, Mauritz; Hessmo, Björn; Schmiedmayer, Jörg

    2002-03-11

    Atoms can be trapped and guided with electromagnetic fields, using nanofabricated structures. We describe the fundamental features of an interferometer for guided matter waves, built of two combined Y-shaped beam splitters. We find that such a device is expected to exhibit high contrast fringes even in a multimode regime, analogous to a white light interferometer.

  4. Noble-Gas Atomic Interferometer

    Science.gov (United States)

    2011-01-19

    Awards W. E. Lamb Medal for Laser Science and Quantum Optics (2008). Lewiner Distinguished Lecturer, Technion, Israel (2009). Graduate Students...effort to explain Maxwell’s demon in terms of information entropy . Single-photon cooling was demonstrated experimentally on magnetically trapped

  5. Michelson Interferometer

    Science.gov (United States)

    Rogers, Ryan

    2007-01-01

    The Michelson Interferometer is a device used in many applications, but here it was used to measure small differences in distance, in the milli-inch range, specifically for defects in the Orbiter windows. In this paper, the method of using the Michelson Interferometer for measuring small distances is explained as well as the mathematics of the system. The coherence length of several light sources was calculated in order to see just how small a defect could be measured. Since white light is a very broadband source, its coherence length is very short and thus can be used to measure small defects in glass. After finding the front and back reflections from a very thin glass slide with ease and calculating the thickness of it very accurately, it was concluded that this system could find and measure small defects on the Orbiter windows. This report also discusses a failed attempt for another use of this technology as well as describes an area of promise for further analysis. The latter of these areas has applications for finding possible defects in Orbiter windows without moving parts.

  6. Atoms

    Institute of Scientific and Technical Information of China (English)

    刘洪毓

    2007-01-01

    Atoms(原子)are all around us.They are something like the bricks (砖块)of which everything is made. The size of an atom is very,very small.In just one grain of salt are held millions of atoms. Atoms are very important.The way one object acts depends on what

  7. Special relativity and interferometers

    Science.gov (United States)

    Han, D.; Kim, Y. S.

    1988-01-01

    A new generation of gravitational wave detectors is expected to be based on interferometers. Yurke et al. (1986) introduced a class of interferometers characterized by SU(1,1) which can in principle achieve a phase sensitivity approaching 1/N, where N is thte total number of photons entering the interferometer. It is shown here that the SU(1,1) interferometer can serve as an analog computer for Wigner's little group of the Poincare\\'| group.

  8. The Palomar Testbed Interferometer

    OpenAIRE

    Colavita, M. M.; Wallace, J. K.

    1998-01-01

    The Palomar Testbed Interferometer (PTI) is a long-baseline infrared interferometer located at Palomar Observatory, California. It was built as a testbed for interferometric techniques applicable to the Keck Interferometer. First fringes were obtained in July 1995. PTI implements a dual-star architecture, tracking two stars simultaneously for phase referencing and narrow-angle astrometry. The three fixed 40-cm apertures can be combined pair-wise to provide baselines to 110 m. The interferomet...

  9. Special relativity and interferometers

    Science.gov (United States)

    Han, D.; Kim, Y. S.

    1988-01-01

    A new generation of gravitational wave detectors is expected to be based on interferometers. Yurke et al. (1986) introduced a class of interferometers characterized by SU(1,1) which can in principle achieve a phase sensitivity approaching 1/N, where N is thte total number of photons entering the interferometer. It is shown here that the SU(1,1) interferometer can serve as an analog computer for Wigner's little group of the Poincare\\'| group.

  10. Study on talbot pattern for grating interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Ju; Oh, Oh Sung; Lee, Seung Wook [Dept. of School of Mechanical Engineering, Pusan National University, Busan (Korea, Republic of); Kim, Jong Yul [Neutron Instrument Division, Korea Atomic Energy Reserch Institute, Daejeon (Korea, Republic of)

    2015-04-15

    One of properties which X-ray and Neutron can be applied nondestructive test is penetration into the object with interaction leads to decrease in intensity. X-ray interaction with the matter caused by electrons, Neutron caused by atoms. They share applications in nondestructive test area because of their similarities of interaction mechanism. Grating interferometer is the one of applications produces phase contrast image and dark field image. It is defined by Talbot interferometer and Talbot-Lau interferometer according to Talbot effect and Talbot-Lau effect respectively. Talbot interferometer works with coherence beam like X-ray, and Talbot-Lau has an effect with incoherence beam like Neutron. It is important to expect the interference in grating interferometer compared normal nondestructive system. In this paper, simulation works are conducted according to Talbot and Talbot-Lau interferometer in case of X-ray and Neutron. Variation of interference intensity with X-ray and Neutron based on wave theory is constructed and calculate elements consist the system. Additionally, Talbot and Talbot-Lau interferometer is simulated in different kinds of conditions.

  11. Inertial measurement using atom interferometry

    Institute of Scientific and Technical Information of China (English)

    JIA; Aiai; YANG; Jun; YAN; Shuhua; LUO; Yukun; HU; Qingqing; WEI; Chunhua; LI; Zehuan

    2015-01-01

    The recent advances of atom interferometer and its application in precision inertial measurement are review ed. The principle,characteristics and implementation of atom interferometer are introduced and it can be used to measure gravitational acceleration,gravity gradient and rotation for its high sensitivity. We also present the principle,structure and new progress of gravimeter,gravity gradiometer and gyroscope based on atom interferometer.

  12. Design of laser frequency and power control system in atom interferometer%原子干涉仪中激光频率和光强控制系统的设计

    Institute of Scientific and Technical Information of China (English)

    胡朝晖; 杨婷; 亓鲁

    2014-01-01

    为了对铯原子外态干涉仪的激光束精密控制,设计了一套适用于多种需求的激光频率和光强控制系统。该系统基于声光调制器,并集成了激光移频、光强稳定和光强调制等功能。首先,根据原子干涉仪的原理,提出对激光的要求和指标。接着,按照提出的要求设计了集成锁相频率合成器等硬件电路系统和LabVIEW软件控制系统。最后,对所开发的系统进行了实验测试。实验结果表明:系统的移频范围可控制在100~200 MHz;光强稳定性好,采用稳光系统后输出光强的波动减小为2%。设计的这套系统功能齐全,可靠有效,实现预期目标,满足原子干涉仪对光学系统的要求。另外此系统还可以应用到其他需要系统中,比如原子钟、原子干涉重力梯度仪等。%In order to control laser beams precisely in a caesium atom interferometer,a laser frequency and power con-trol system which is suitable for various demands is designed. Based on an acousto-optical modulator,the system in-tegrates the functions of frequency shift,power stabilization and modulation. Firstly,based on the principle of the at-om interferometer,the requirement of the optical part in the system is proposed. Secondly,the hardware circuit sys-tem including a phase-locked loop frequency synthesizer and the LabVIEW software control system are designed. Fi-nally,the developed system is tested. The experimental results show that the frequency shift range of the laser beam through the acousto-optical modulator is 100~200MHz;and the power fluctuation of the laser decrease to 2% using the power stabilization system. The designed system has multi-functions,achieves the desired aims and satisfies the requirements of atom transition,matter wave interference and other processes to laser beams. In addition,the de-signed system could be applied to other systems which need to adjust and control laser beam precisely,such as

  13. Plasma flow velocity measurements using a modulated Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J. [Australian National Univ., Canberra, ACT (Australia). Plasma Research Lab.; Meijer, F.G. [FOM-Instituut voor Plasmafysica `Rijnhuizen`, Association Euratom-FOM, PO Box 1207, 3430 BE Nieuwegein (Netherlands)]|[Physics Faculty, University of Amsterdam, Amsterdam (Netherlands)

    1997-03-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (orig.) 1 refs.

  14. Atom Interferometry for Fundamental Physics and Gravity Measurements in Space

    Science.gov (United States)

    Kohel, James M.

    2012-01-01

    Laser-cooled atoms are used as freefall test masses. The gravitational acceleration on atoms is measured by atom-wave interferometry. The fundamental concept behind atom interferometry is the quantum mechanical particle-wave duality. One can exploit the wave-like nature of atoms to construct an atom interferometer based on matter waves analogous to laser interferometers.

  15. Atom Interferometry for Fundamental Physics and Gravity Measurements in Space

    Science.gov (United States)

    Kohel, James M.

    2012-01-01

    Laser-cooled atoms are used as freefall test masses. The gravitational acceleration on atoms is measured by atom-wave interferometry. The fundamental concept behind atom interferometry is the quantum mechanical particle-wave duality. One can exploit the wave-like nature of atoms to construct an atom interferometer based on matter waves analogous to laser interferometers.

  16. Nonlinearity-reduced interferometer

    Science.gov (United States)

    Wu, Chien-ming

    2007-12-01

    Periodic nonlinearity is a systematic error limiting the accuracy of displacement measurements at the nanometer level. It results from many causes such as the frequency mixing, polarization mixing, polarization-frequency mixing, and the ghost reflections. An interferometer having accuracy in displacement measurement of less than one-nanometer is necessary in nanometrology. To meet the requirement, the periodic nonlinearity should be less than deep sub-nanometer. In this paper, a nonlinearity-reduced interferometry has been proposed. Both the linear- and straightness-interferometer were tested. The developed interferometer demonstrated of a residual nonlinearity less than 25 pm.

  17. Michelson and His Interferometer

    Science.gov (United States)

    Shankland, Robert S.

    1974-01-01

    Presents a brief historical account of Michelson's invention of his interferometer with some subsequent ingenious applications of its capabilities for precise measurement discussed in details, including the experiment on detrmination of the diameters for heavenly bodies. (CC)

  18. Testing the Gravitational Redshift with Atomic Gravimeters?

    CERN Document Server

    Wolf, Peter; Bordé, Christian J; Reynaud, Serge; Salomon, Christophe; Cohen-Tannoudji, Claude

    2011-01-01

    Atom interferometers allow the measurement of the acceleration of freely falling atoms with respect to an experimental platform at rest on Earth's surface. Such experiments have been used to test the universality of free fall by comparing the acceleration of the atoms to that of a classical freely falling object. In a recent paper, M\\"uller, Peters and Chu [Nature {\\bf 463}, 926-929 (2010)] argued that atom interferometers also provide a very accurate test of the gravitational redshift (or universality of clock rates). Considering the atom as a clock operating at the Compton frequency associated with the rest mass, they claimed that the interferometer measures the gravitational redshift between the atom-clocks in the two paths of the interferometer at different values of gravitational potentials. In the present paper we analyze this claim in the frame of general relativity and of different alternative theories, and conclude that the interpretation of atom interferometers as testing the gravitational redshift ...

  19. Mariner 9 Michelson interferometer.

    Science.gov (United States)

    Hanel, R.; Schlachman, B.; Rodgers, D.; Breihan, E.; Bywaters, R.; Chapman, F.; Rhodes, M.; Vanous, D.

    1972-01-01

    The Michelson interferometer on Mariner 9 measures the thermal emission spectrum of Mars between 200 and 2000 per cm (between 5 and 50 microns) with a spectral resolution of 2.4 per cm in the apodized mode. A noise equivalent radiance of 0.5 x 10 to the minus 7th W/sq cm/ster/cm is deduced from data recorded in orbit around Mars. The Mariner interferometer deviates in design from the Nimbus 3 and 4 interferometers in several areas, notably, by a cesium iodide beam splitter and certain aspects of the digital information processing. Special attention has been given to the problem of external vibration. The instrument performance is demonstrated by calibration data and samples of Mars spectra.

  20. Heterodyne Interferometer Angle Metrology

    Science.gov (United States)

    Hahn, Inseob; Weilert, Mark A.; Wang, Xu; Goullioud, Renaud

    2010-01-01

    A compact, high-resolution angle measurement instrument has been developed that is based on a heterodyne interferometer. The common-path heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer setup, an optical mask is used to sample the measurement laser beam reflecting back from a target surface. Angular rotations, around two orthogonal axes in a plane perpendicular to the measurement- beam propagation direction, are determined simultaneously from the relative displacement measurement of the target surface. The device is used in a tracking telescope system where pitch and yaw measurements of a flat mirror were simultaneously performed with a sensitivity of 0.1 nrad, per second, and a measuring range of 0.15 mrad at a working distance of an order of a meter. The nonlinearity of the device is also measured less than one percent over the measurement range.

  1. Relativistic effects in atom gravimeters

    Science.gov (United States)

    Tan, Yu-Jie; Shao, Cheng-Gang; Hu, Zhong-Kun

    2017-01-01

    Atom interferometry is currently developing rapidly, which is now reaching sufficient precision to motivate laboratory tests of general relativity. Thus, it is extremely significant to develop a general relativistic model for atom interferometers. In this paper, we mainly present an analytical derivation process and first give a complete vectorial expression for the relativistic interferometric phase shift in an atom interferometer. The dynamics of the interferometer are studied, where both the atoms and the light are treated relativistically. Then, an appropriate coordinate transformation for the light is performed crucially to simplify the calculation. In addition, the Bordé A B C D matrix combined with quantum mechanics and the "perturbation" approach are applied to make a methodical calculation for the total phase shift. Finally, we derive the relativistic phase shift kept up to a sensitivity of the acceleration ˜1 0-14 m/s 2 for a 10 -m -long atom interferometer.

  2. Analysis of Atom-Interferometer Clocks

    Science.gov (United States)

    2014-01-21

    particle has been mostly ignored [3]. But in recent years it has appeared in the literature with claims that the redshift of the Compton oscillation... literature it has been claimed that ω0 does not correspond to a physical oscillation, with the points being made that it is not Doppler shifted to an...Peters, and S. Chu, Nature (London) 463, 926 (2010). [5] P. Catillon, N. Cue, M. J. Gaillard, R. Genre , M. Gouanère, R. G. Kirsch, J. C. Poizat, J

  3. Atom Interferometry in a Warm Vapor

    CERN Document Server

    Biedermann, G W; Rakholia, A V; Jau, Y -Y; Wheeler, D R; Sterk, J D; Burns, G R

    2016-01-01

    We demonstrate matterwave interference in a warm vapor of rubidium atoms. Established approaches to light pulse atom interferometry rely on laser cooling to concentrate a large ensemble of atoms into a velocity class resonant with the atom optical light pulse. In our experiment, we show that clear interference signals may be obtained without laser cooling. This effect relies on the Doppler selectivity of the atom interferometer resonance. This interferometer may be configured to measure accelerations, and we demonstrate that multiple interferometers may be operated simultaneously by addressing multiple velocity classes.

  4. Japanese large-scale interferometers

    CERN Document Server

    Kuroda, K; Miyoki, S; Ishizuka, H; Taylor, C T; Yamamoto, K; Miyakawa, O; Fujimoto, M K; Kawamura, S; Takahashi, R; Yamazaki, T; Arai, K; Tatsumi, D; Ueda, A; Fukushima, M; Sato, S; Shintomi, T; Yamamoto, A; Suzuki, T; Saitô, Y; Haruyama, T; Sato, N; Higashi, Y; Uchiyama, T; Tomaru, T; Tsubono, K; Ando, M; Takamori, A; Numata, K; Ueda, K I; Yoneda, H; Nakagawa, K; Musha, M; Mio, N; Moriwaki, S; Somiya, K; Araya, A; Kanda, N; Telada, S; Sasaki, M; Tagoshi, H; Nakamura, T; Tanaka, T; Ohara, K

    2002-01-01

    The objective of the TAMA 300 interferometer was to develop advanced technologies for kilometre scale interferometers and to observe gravitational wave events in nearby galaxies. It was designed as a power-recycled Fabry-Perot-Michelson interferometer and was intended as a step towards a final interferometer in Japan. The present successful status of TAMA is presented. TAMA forms a basis for LCGT (large-scale cryogenic gravitational wave telescope), a 3 km scale cryogenic interferometer to be built in the Kamioka mine in Japan, implementing cryogenic mirror techniques. The plan of LCGT is schematically described along with its associated R and D.

  5. Fabry-Perot interferometers

    CERN Document Server

    Mora-Hernandez, G

    1988-01-01

    This book describes the Fabry-Perot interferometer and its variants as well as its use, optimisation and applications. The author begins with an historical perspective on the development of the instrument. Because of the quantitative uses of the device, the text tends to be mostly mathematical in its treatment. However, there is also much practical detail on the use and optimization of the Fabry-Perot interferometer and discussion of its classical uses (such as in metrology) and its contemporary applications (such as in lasers). In addition the book contains a comprehensive bibliography summarizing the extensive literature on the subject. This book will appeal both to high-resolution practitioners, such as spectroscopists, and to the laser community, since the Fabrv-Perot is not only an integral part of the laser but is also usea to characterize its optical and spectroscopic behaviour.

  6. New Developments in Atom Interferometry

    Science.gov (United States)

    1992-07-01

    interferometers can be applied to a number of experiments in fundamental physics: tests of quantum mechanics such as the Aharonov - Casher effect (6), measurement of...qualitatively new types of experiments involving inertial effects , studies of atomic and molecular properties, tests of basic quantum physics, and may ultimately...laser light as the beam splitters. Atom interferometers will make possible qualitatively new types of experiments involving inertial effects , studies of

  7. Guided magnonic Michelson interferometer

    OpenAIRE

    Muhammad H. Ahmed; Jeske, Jan; Greentree, Andrew D.

    2015-01-01

    Magnonics is an emerging field with potential applications in classical and quantum information processing. Freely propagating magnons in two-dimensional media suffer from dispersion, which limits their effective range and fidelity. We show the design of controllable magnonic circuitry, that utilise surface current carrying wires to create magnonic waveguides. We also show the design of a magnonic directional coupler and controllable Michelson interferometer to demonstrate its utility for inf...

  8. Plasma flow velocity measurements using a modulated Michelson interferometer

    NARCIS (Netherlands)

    Howard, J.; Meijer, F. G.

    1997-01-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (C) 1997 Elsevier Science S.A.

  9. Naval Prototype Optical Interferometer (NPOI)

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Used for astrometry and astronomical imaging, the Naval Prototype Optical Interferometer (NPOI) is a distributed aperture optical telescope. It is operated...

  10. Folding gravitational-wave interferometers

    Science.gov (United States)

    Sanders, J. R.; Ballmer, Stefan W.

    2017-01-01

    The sensitivity of kilometer-scale terrestrial gravitational wave interferometers is limited by mirror coating thermal noise. Alternative interferometer topologies can mitigate the impact of thermal noise on interferometer noise curves. In this work, we explore the impact of introducing a single folding mirror into the arm cavities of dual-recycled Fabry–Perot interferometers. While simple folding alone does not reduce the mirror coating thermal noise, it makes the folding mirror the critical mirror, opening up a variety of design and upgrade options. Improvements to the folding mirror thermal noise through crystalline coatings or cryogenic cooling can increase interferometer range by as much as a factor of two over the Advanced LIGO reference design.

  11. Atom interferometry and the Einstein equivalence principle

    CERN Document Server

    Wolf, Peter; Bordé, Christian J; Reynaud, Serge; Salomon, Christophe; Cohen-Tannoudji, Clande

    2011-01-01

    The computation of the phase shift in a symmetric atom interferometer in the presence of a gravitational field is reviewed. The difference of action-phase integrals between the two paths of the interferometer is zero for any Lagrangian which is at most quadratic in position and velocity. We emphasize that in a large class of theories of gravity the atom interferometer permits a test of the weak version of the equivalence principle (or universality of free fall) by comparing the acceleration of atoms with that of ordinary bodies, but is insensitive to that aspect of the equivalence principle known as the gravitational redshift or universality of clock rates.

  12. The Fizeau Interferometer Testbed

    CERN Document Server

    Zhang, X; Lyon, R G; Huet, H; Marzouk, J; Solyar, G; Zhang, Xiaolei; Carpenter, Kenneth G.; Lyon, Richard G.; Huet, Hubert; Marzouk, Joe; Solyar, Gregory

    2002-01-01

    The Fizeau Interferometer Testbed (FIT) is a collaborative effort between NASA's Goddard Space Flight Center, the Naval Research Laboratory, Sigma Space Corporation, and the University of Maryland. The testbed will be used to explore the principles of and the requirements for the full, as well as the pathfinder, Stellar Imager mission concept. It has a long term goal of demonstrating closed-loop control of a sparse array of numerous articulated mirrors to keep optical beams in phase and optimize interferometric synthesis imaging. In this paper we present the optical and data acquisition system design of the testbed, and discuss the wavefront sensing and control algorithms to be used. Currently we have completed the initial design and hardware procurement for the FIT. The assembly and testing of the Testbed will be underway at Goddard's Instrument Development Lab in the coming months.

  13. Guided magnonic Michelson interferometer

    Science.gov (United States)

    Ahmed, Muhammad H.; Jeske, Jan; Greentree, Andrew D.

    2017-01-01

    Magnonics is an emerging field with potential applications in classical and quantum information processing. Freely propagating magnons in two-dimensional media are subject to dispersion, which limits their effective range and utility as information carriers. We show the design of a confining magnonic waveguide created by two surface current carrying wires placed above a spin-sheet, which can be used as a primitive for reconfigurable magnonic circuitry. We theoretically demonstrate the ability of such guides to counter the transverse dispersion of the magnon in a spin-sheet, thus extending the range of the magnon. A design of a magnonic directional coupler and controllable Michelson interferometer is shown, demonstrating its utility for information processing tasks.

  14. THE KECK INTERFEROMETER NULLER

    Energy Technology Data Exchange (ETDEWEB)

    Serabyn, E.; Mennesson, B.; Colavita, M. M. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Koresko, C. [Argon ST, Inc., 1386 Connellsville Road, Lemont Furnace, PA 15456 (United States); Kuchner, M. J., E-mail: Gene.Serabyn@jpl.nasa.gov [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2012-03-20

    The Keck Interferometer Nuller (KIN), the first operational separated-aperture infrared nulling interferometer, was designed to null the mid-infrared emission from nearby stars so as to ease the measurement of faint circumstellar emission. This paper describes the basis of the KIN's four-beam, two-stage measurement approach and compares it to the simpler case of a two-beam nuller. In the four-beam KIN system, the starlight is first nulled in a pair of nullers operating on parallel 85 m Keck-Keck baselines, after which 'cross-combination' on 4 m baselines across the Keck apertures is used to modulate and detect residual coherent off-axis emission. Comparison to the constructive stellar fringe provides calibration. The response to an extended source is similar in the two cases, except that the four-beam response includes a term due to the visibility of the source on the cross-combiner baseline-a small effect for relatively compact sources. The characteristics of the dominant null depth errors are also compared for the two cases. In the two-beam nuller, instrumental imperfections and asymmetries lead to a series of quadratic, positive-definite null leakage terms. For the four-beam nuller, the leakage is instead a series of correlation cross-terms combining corresponding errors in each of the two nullers, which contribute offsets only to the extent that these errors are correlated on the timescale of the measurement. This four-beam architecture has allowed a significant ({approx}order of magnitude) improvement in mid-infrared long-baseline fringe-visibility accuracies.

  15. MIT's interferometer CST testbed

    Science.gov (United States)

    Hyde, Tupper; Kim, Ed; Anderson, Eric; Blackwood, Gary; Lublin, Leonard

    1990-12-01

    The MIT Space Engineering Research Center (SERC) has developed a controlled structures technology (CST) testbed based on one design for a space-based optical interferometer. The role of the testbed is to provide a versatile platform for experimental investigation and discovery of CST approaches. In particular, it will serve as the focus for experimental verification of CSI methodologies and control strategies at SERC. The testbed program has an emphasis on experimental CST--incorporating a broad suite of actuators and sensors, active struts, system identification, passive damping, active mirror mounts, and precision component characterization. The SERC testbed represents a one-tenth scaled version of an optical interferometer concept based on an inherently rigid tetrahedral configuration with collecting apertures on one face. The testbed consists of six 3.5 meter long truss legs joined at four vertices and is suspended with attachment points at three vertices. Each aluminum leg has a 0.2 m by 0.2 m by 0.25 m triangular cross-section. The structure has a first flexible mode at 31 Hz and has over 50 global modes below 200 Hz. The stiff tetrahedral design differs from similar testbeds (such as the JPL Phase B) in that the structural topology is closed. The tetrahedral design minimizes structural deflections at the vertices (site of optical components for maximum baseline) resulting in reduced stroke requirements for isolation and pointing of optics. Typical total light path length stability goals are on the order of lambda/20, with a wavelength of light, lambda, of roughly 500 nanometers. It is expected that active structural control will be necessary to achieve this goal in the presence of disturbances.

  16. The photothermal effect in interferometers

    CERN Document Server

    Rao, S R

    2002-01-01

    We have measured the photothermal effect in a single cross-polarized interferometer at audio frequencies (5 Hz - 4 kHz). In a Fabry-Perot interferometer, light in one polarization is chopped to periodically heat the interferometer mirrors, while light in the orthogonal polarization measures the mirror length changes. Tests of a polished solid metal mirror show good agreement with relevant proposed theories by Braginsky et al. ["Thermodynamical fluctuations and photo-thermal shot noise in gravitational wave antennae," Physics Letters A 264, 1-10 (1999)] and Cerdonio et al. ["Thermoelastic effects at low temperatures and quantum limits in displacement measurements," Physical Review D 63 082003 (2001)] describing uncoated optics.

  17. Atom Interferometry for detection of Gravity Waves-a Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Atom interferometers are more sensitive to inertial effects. This is because atoms in their inertial frame are ideal test masses for detection of gravity effects...

  18. Balloon Exoplanet Nulling Interferometer (BENI)

    Science.gov (United States)

    Lyon, Richard G.; Clampin, Mark; Woodruff, Robert A.; Vasudevan, Gopal; Ford, Holland; Petro, Larry; Herman, Jay; Rinehart, Stephen; Carpenter, Kenneth; Marzouk, Joe

    2009-01-01

    We evaluate the feasibility of using a balloon-borne nulling interferometer to detect and characterize exosolar planets and debris disks. The existing instrument consists of a 3-telescope Fizeau imaging interferometer with 3 fast steering mirrors and 3 delay lines operating at 800 Hz for closed-loop control of wavefront errors and fine pointing. A compact visible nulling interferometer is under development which when coupled to the imaging interferometer would in-principle allow deep suppression of starlight. We have conducted atmospheric simulations of the environment above 100,000 feet and believe balloons are a feasible path forward towards detection and characterization of a limited set of exoplanets and their debris disks. Herein we will discuss the BENI instrument, the balloon environment and the feasibility of such as mission.

  19. Michelson interferometer for measuring temperature

    OpenAIRE

    Xie, Dong; Xu, Chunling; Wang, Anmin

    2016-01-01

    We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displa...

  20. Dynamic splitting and merging of an atom cloud on an atom chip

    Institute of Scientific and Technical Information of China (English)

    Ke Min; Yan Bo; Cheng Feng; Wang Yu-Zhu

    2009-01-01

    Chip-based atom interferometers bring together the advantages of atom chips and Bose-Einstein condensates. Their central prerequisite is that a condensate can be coherently split into two halves with a determined relative phase. This paper demonstrates the dynamical splitting and merging of an atom cloud with two U-wires on an atom chip. Symmetrical and asymmetrical splittings are realized by applying a bias field with different directions and magnitudes. The trajectories of the splitting are consistent with theoretical calculations. The atom chip is a good candidate for constructing an atom interferometer.

  1. Polarizing Michelson interferometer for measuring thermospheric winds

    Energy Technology Data Exchange (ETDEWEB)

    Bird, J.C.

    1991-01-01

    The Polarizing Atmospheric Michelson Interferometer, PAMI, a new version of the Wide Angle Michelson Interferometer, is used to measure winds in the termosphere. In the polarizing instrument, the optical path difference is changed simply by rotating a polarizing filter external to the interferometer. This allows a very simple scanning mechanism. PAMI is similar to other instruments such as WAMDII that measure thermospheric winds and temperatures, retaining the benefits of high light throughput, while offering advantages including lower cost, simplicity, and portability. The instrument is highly sensitive and thus is designed to be used for field measurements at locations far from city lights. Results are shown from the AIDA observation campaign in Puerto Rico where coordinated observations were made by PAMI along with other optical and radio measurements during April and May 1989. Intensities of the green line layer at 95 km were compared to those observed by several other instruments. For example, MORTI (Mesopause Oxygen Rotational Temperature Imager), a colocated instrument which was looking at the 94 km 867.6 nm molecular oxygen emission. MORTI and PAMI emission rates were found to show the same trends. On the brightest night recorded during April, the zenith emission rate reached over 400 Rayleighs; emission enhancements were sometimes related to auroral events. During the observing period of April 4 to April 11, 1989, most of the observations of the 94 km airglow were after midnight where the winds were found to be generally towards the north east at about 50 to 100 m/s. During auroral activity this wind vector always turned counterclockwise, towards the west. During the nights of May 2 and May 6 these wind vectors follow a wave-like variation in magnitude and direction. It is concluded that auroral activity changes the global circulation in a way that sometimes transports increased amounts of oxygen atoms over Arecibo.

  2. Michelson Interferometer (MINT)

    Science.gov (United States)

    Lacis, Andrew; Carlson, Barbara

    1993-01-01

    MINT is a Michelson interferometer designed to measure the thermal emission from the earth at high spectral resolution (2/cm) over a broad spectral range (250-1700/cm, 6-40 mu m) with contiguous 3-pixel wide (12 mrad, 8 km field of view) along-track sampling. MINT is particularly well suited for monitoring cloud properties (cloud cover, effective temperature, optical thickness, ice/water phase, and effective particle size) both day and night, as well as tropospheric water vapor, ozone, and temperature. The key instrument characteristics that make MINT ideally suited for decadal monitoring purposes are: high wavelength to wavelength precision across the full IR spectrum with high spectral resolution; space-proven long-term durability and calibration stability; and small size, low cost, low risk instrument incorporating the latest detector and electronics technology. MINT also incorporates simplicity in design and operation by utilizing passively cooled DTGS detectors and nadir viewing geometry (with target motion compensation). MINT measurement objectives, instrument characteristics, and key advantages are summarized in this paper.

  3. Long-term laser frequency stabilization using fiber interferometers

    CERN Document Server

    Kong, Jia; Jimenez-Martinez, Ricardo; Mitchell, Morgan W

    2014-01-01

    We report long-term laser frequency stabilization using only the target laser and a pair of 5 m fiber interferometers, one as a frequency reference and the second as a sensitive thermometer. When used to stabilize a distributed feedback laser at 795 nm, the frequency Allan deviation at 1000 s drops from 5.6*10^{-8} to 6.9*10^{-10}. The performance equals that of an offset lock employing a second laser and an atomic reference.

  4. Microfabrication of gold wires for atom guides

    OpenAIRE

    Kukharenka, Elena; Moktadir, Zak; Kraft, Michael; Abdelsalam, M.E.; Bagnall, Darren; Vale, C.; Jones, M. P. A.; Hinds, E.A.

    2004-01-01

    Miniaturised atom optics is a new field allowing the control of cold atoms in microscopic magnetic traps and waveguides. Using microstructures (hereafter referred to as atom chips), the control of cold atoms on the micrometer scale becomes possible. Applications range from integrated atom interferometers to the realisation of quantum gates. The implementation of such structures requires high magnetic field gradients.\\ud The motivation of this work was to develop a suitable fabrication process...

  5. 0.75 atoms improve the clock signal of 10,000 atoms

    DEFF Research Database (Denmark)

    Kruse, I.; Lange, K.; Peise, Jan

    2017-01-01

    Since the pioneering work of Ramsey, atom interferometers are employed for precision metrology, in particular to measure time and to realize the second. In a classical interferometer, an ensemble of atoms is prepared in one of the two input states, whereas the second one is left empty. In this case.......75 atoms to improve the clock sensitivity of 10,000 atoms by 2.05 dB. The SQL poses a significant limitation for today's microwave fountain clocks, which serve as the main time reference. We evaluate the major technical limitations and challenges for devising a next generation of fountain clocks based...... on atomic squeezed vacuum....

  6. Liquid-helium-cooled Michelson interferometer

    Science.gov (United States)

    Augason, G. C.; Young, N.

    1972-01-01

    Interferometer serves as a rocket-flight spectrometer for examination of the far infrared emission spectra of astronomical objects. The double beam interferometer is readily adapted to make spectral scans and for use as a detector of discrete line emissions.

  7. Standing waves in fiber-optic interferometers

    NARCIS (Netherlands)

    De Haan, V.; Santbergen, R.; Tijssen, M.; Zeman, M.

    2011-01-01

    A study is presented giving the response of three types of fiber-optic interferometers by which a standing wave through an object is investigated. The three types are a Sagnac, Mach–Zehnder and Michelson–Morley interferometer. The response of the Mach–Zehnder interferometer is similar to the Sagnac

  8. Integrated Mach-Zehnder interferometer for Bose-Einstein condensates.

    Science.gov (United States)

    Berrada, T; van Frank, S; Bücker, R; Schumm, T; Schaff, J-F; Schmiedmayer, J

    2013-01-01

    Particle-wave duality enables the construction of interferometers for matter waves, which complement optical interferometers in precision measurement devices. This requires the development of atom-optics analogues to beam splitters, phase shifters and recombiners. Integrating these elements into a single device has been a long-standing goal. Here we demonstrate a full Mach-Zehnder sequence with trapped Bose-Einstein condensates confined on an atom chip. Particle interactions in our Bose-Einstein condensate matter waves lead to a nonlinearity, absent in photon optics. We exploit it to generate a non-classical state having reduced number fluctuations inside the interferometer. Making use of spatially separated wave packets, a controlled phase shift is applied and read out by a non-adiabatic matter-wave recombiner. We demonstrate coherence times a factor of three beyond what is expected for coherent states, highlighting the potential of entanglement as a resource for metrology. Our results pave the way for integrated quantum-enhanced matter-wave sensors.

  9. Demonstration of improved sensitivity of echo interferometers to gravitational acceleration

    CERN Document Server

    Mok, C; Carew, A; Berthiaume, R; Beattie, S; Kumarakrishnan, A

    2013-01-01

    We have developed two configurations of an echo interferometer that rely on standing wave excitation of a laser-cooled sample of rubidium atoms that measures acceleration. For a two-pulse configuration, the interferometer signal is modulated at the recoil frequency and exhibits a sinusoidal frequency chirp as a function of pulse spacing. For a three-pulse stimulated echo configuration, the signal is observed without recoil modulation and exhibits a modulation at a single frequency. The three-pulse configuration is less sensitive to effects of vibrations and magnetic field curvature leading to a longer experimental timescale. For both configurations of the atom interferometer (AI), we show that a measurement of acceleration with a statistical precision of 0.5% can be realized by analyzing the shape of the echo envelope that has a temporal duration of a few microseconds. Using the two-pulse AI, we obtain measurements of acceleration that are statistically precise to 6 parts per million (ppm) on a 25 ms timescal...

  10. Slow light Mach-Zehnder fiber interferometer

    Institute of Scientific and Technical Information of China (English)

    Yundong Zhang; Jinfang Wang; Xuenan Zhang; Hao Wu; Yuanxue Cai; Jing Zhang; Ping Yuan

    2012-01-01

    A slow light structure Mach-Zehnder fiber interferometer is theoretically demonstrated.The sensitivity of the interferometer is significantly enhanced by the dispersion of the slow light structure.The numerical results show that the sensitivity enhancement factor varies with the coupling coefficient and reaches its maximum under critical coupling conditions.Interferometers have been investigated in relation to their applications in fields such as metrology[1],optical sensing[2],optical communication[3,4],quantum information processing[5],and biomedical engineering[6].A number of schemes have been proposed to improve the performance of interferometers[7],such as using photonic crystal structures to minimize the size of on-chip devices[8],utilizing the dispersive property of semiconductor to enhance the spectral sensitivity of interferometers[9,10],utilizing slow light medium to enhance the resolution of Fourier transform interferometer[11],exploiting fast light medium or slow light structure to increase the rotation sensitivity of a Sagnac interferometer[12,13],enhancing the transmittance of the Mach-Zehnder interferometer (MZI) in the slow light region by gratings[14],and using liquid crystal light valve to derive high sensitivity interferometers[15].%A slow light structure Mach-Zehnder fiber interferometer is theoretically demonstrated. The sensitivity of the interferometer is significantly enhanced by the dispersion of the slow light structure. The numerical results show that the sensitivity enhancement factor varies with the coupling coefficient and reaches its maximum under critical coupling conditions.

  11. Standing waves in fiber-optic interferometers.

    Science.gov (United States)

    de Haan, V; Santbergen, R; Tijssen, M; Zeman, M

    2011-10-10

    A study is presented giving the response of three types of fiber-optic interferometers by which a standing wave through an object is investigated. The three types are a Sagnac, Mach-Zehnder and Michelson-Morley interferometer. The response of the Mach-Zehnder interferometer is similar to the Sagnac interferometer. However, the Sagnac interferometer is much harder to study because of the fact that one input port and output port coincide. Further, the Mach-Zehnder interferometer has the advantage that the output ports are symmetric, reducing the systematic effects. Examples of standing wave light absorption in several simple objects are given. Attention is drawn to the influence of standing waves in fiber-optic interferometers with weak-absorbing layers incorporated. A method is described for how these can be theoretically analyzed and experimentally measured. Further experiments are needed for a thorough comparison between theory and experiment.

  12. TIMED Doppler Interferometer: Overview and recent results

    Science.gov (United States)

    Killeen, T. L.; Wu, Q.; Solomon, S. C.; Ortland, D. A.; Skinner, W. R.; Niciejewski, R. J.; Gell, D. A.

    2006-10-01

    The Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite carries a limb-scanning Fabry-Perot interferometer designed to perform remote-sensing measurements of upper atmosphere winds and temperatures globally. This instrument is called the TIMED Doppler Interferometer, or TIDI. This paper provides an overview of the TIDI instrument design, on-orbit performance, operational modes, data processing and inversion procedures, and a summary of wind results to date. Daytime and nighttime neutral winds in the mesosphere and lower thermosphere/ionosphere (MLTI) are measured on TIDI using four individual scanning telescopes that collect light from various upper atmosphere airglow layers on both the cold and warm sides of the high-inclination TIMED spacecraft. The light is spectrally analyzed using an ultrastable plane etalon Fabry-Perot system with sufficient spectral resolution to determine the Doppler line characteristics of atomic and molecular emissions emanating from the MLTI. The light from all four telescopes and from an internal calibration field passes through the etalon and is combined on a single image plane detector using a Circle-to-Line Interferometer Optic (CLIO). The four geophysical fields provide orthogonal line-of-sight measurements to either side of the satellite's path and these are analyzed to produce altitude profiles of vector winds in the MLTI. The TIDI wind measurements presented here are from the molecular oxygen (0-0) band, covering the altitude region 85-105 km. The unique TIDI design allows for more extended local time coverage of wind structures than previous wind-measuring instruments from high-inclination satellites. The TIDI operational performance has been nominal except for two anomalies: (1) higher than expected background white light caused by a low-level light leak and (2) ice deposition on cold optical surfaces. Both anomalies are well understood and the instrumental modes and data analysis techniques have been

  13. Applications of chirped Raman adiabatic rapid passage to atom interferometry

    Science.gov (United States)

    Kotru, Krish; Butts, David L.; Kinast, Joseph M.; Johnson, David M. S.; Radojevic, Antonije M.; Timmons, Brian P.; Stoner, Richard E.

    2012-02-01

    We present robust atom optics, based on chirped Raman adiabatic rapid passage (ARP), in the context of atom interferometry. Such ARP light pulses drive coherent population transfer between two hyperfine ground states by sweeping the frequency difference of two fixed-intensity optical fields with large single photon detunings. Since adiabatic transfer is less sensitive to atom temperature and non-uniform Raman beam intensity than standard Raman pulses, this approach should improve the stability of atom interferometers operating in dynamic environments. In such applications, chirped Raman ARP may also provide advantages over the previously demonstrated stimulated Raman adiabatic passage (STIRAP) technique, which requires precise modulation of beam intensity and zeroing of the single photon detuning. We demonstrate a clock interferometer with chirped Raman ARP pulses, and compare its stability to that of a conventional Raman pulse interferometer. We also discuss potential improvements to inertially sensitive atom interferometers. Copyright 2011 by The Charles Stark Draper Laboratory, Inc. All rights reserved.

  14. Atomic emission spectroscopy

    Science.gov (United States)

    Andrew, K. H.

    1975-01-01

    The relationship between the Slater-Condon theory and the conditions within the atom as revealed by experimental data was investigated. The first spectrum of Si, Rb, Cl, Br, I, Ne, Ar, and Xe-136 and the second spectrum of As, Cu, and P were determined. Methods for assessing the phase stability of fringe counting interferometers and the design of an autoranging scanning system for digitizing the output of an infrared spectrometer and recording it on magnetic tape are described.

  15. Stellar Interferometer Technology Experiment (SITE)

    Science.gov (United States)

    Crawley, Edward F.; Miller, David; Laskin, Robert; Shao, Michael

    1995-02-01

    The MIT Space Engineering Research Center and the Jet Propulsion Laboratory stand ready to advance science sensor technology for discrete-aperture astronomical instruments such as space-based optical interferometers. The objective of the Stellar Interferometer Technology Experiment (SITE) is to demonstrate system-level functionality of a space-based stellar interferometer through the use of enabling and enhancing Controlled-Structures Technologies (CST). SITE mounts to the Mission Peculiar Experiment Support System inside the Shuttle payload bay. Starlight, entering through two apertures, is steered to a combining plate where it is interferred. Interference requires 27 nanometer pathlength (phasing) and 0.29 archsecond wavefront-tilt (pointing) control. The resulting 15 milli-archsecond angular resolution exceeds that of current earth-orbiting telescopes while maintaining low cost by exploiting active optics and structural control technologies. With these technologies, unforeseen and time-varying disturbances can be rejected while relaxing reliance on ground alignment and calibration. SITE will reduce the risk and cost of advanced optical space systems by validating critical technologies in their operational environment. Moreover, these technologies are directly applicable to commercially driven applications such as precision matching, optical scanning, and vibration and noise control systems for the aerospace, medical, and automotive sectors. The SITE team consists of experienced university, government, and industry researchers, scientists, and engineers with extensive expertise in optical interferometry, nano-precision opto-mechanical control and spaceflight experimentation. The experience exists and the technology is mature. SITE will validate these technologies on a functioning interferometer science sensor in order to confirm definitely their readiness to be baselined for future science missions.

  16. Unequal-Arms Michelson Interferometers

    Science.gov (United States)

    Tinto, Massimo; Armstrong, J. W.

    2000-01-01

    Michelson interferometers allow phase measurements many orders of magnitude below the phase stability of the laser light injected into their two almost equal-length arms. If, however, the two arms are unequal, the laser fluctuations can not be removed by simply recombining the two beams. This is because the laser jitters experience different time delays in the two arms, and therefore can not cancel at the photo detector. We present here a method for achieving exact laser noise cancellation, even in an unequal-arm interferometer. The method presented in this paper requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam. By linearly combining the two data sets with themselves, after they have been properly time shifted, we show that it is possible to construct a new data set that is free of laser fluctuations. An application of this technique to future planned space-based laser interferometer detector3 of gravitational radiation is discussed.

  17. Polarized-interferometer feasibility study

    Science.gov (United States)

    Raab, F. H.

    1983-01-01

    The feasibility of using a polarized-interferometer system as a rendezvous and docking sensor for two cooperating spacecraft was studied. The polarized interferometer is a radio frequency system for long range, real time determination of relative position and attitude. Range is determined by round trip signal timing. Direction is determined by radio interferometry. Relative roll is determined from signal polarization. Each spacecraft is equipped with a transponder and an antenna array. The antenna arrays consist of four crossed dipoles that can transmit or receive either circularly or linearly polarized signals. The active spacecraft is equipped with a sophisticated transponder and makes all measurements. The transponder on the passive spacecraft is a relatively simple repeater. An initialization algorithm is developed to estimate position and attitude without any a priori information. A tracking algorithm based upon minimum variance linear estimators is also developed. Techniques to simplify the transponder on the passive spacecraft are investigated and a suitable configuration is determined. A multiple carrier CW signal format is selected. The dependence of range accuracy and ambiguity resolution error probability are derived and used to design a candidate system. The validity of the design and the feasibility of the polarized interferometer concept are verified by simulation.

  18. Decoherence Spectroscopy for Atom Interferometry

    Directory of Open Access Journals (Sweden)

    Raisa Trubko

    2016-08-01

    Full Text Available Decoherence due to photon scattering in an atom interferometer was studied as a function of laser frequency near an atomic resonance. The resulting decoherence (contrast-loss spectra will be used to calibrate measurements of tune-out wavelengths that are made with the same apparatus. To support this goal, a theoretical model of decoherence spectroscopy is presented here along with experimental tests of this model.

  19. Bloch oscillations in atom interferometry

    CERN Document Server

    Cladé, Pierre

    2014-01-01

    In Paris, we are using an atom interferometer to precisely measure the recoil velocity of an atom that absorbs a photon. In order to reach a high sensitivity, many recoils are transferred to atoms using the Bloch oscillations technique. In this lecture, I will present in details this technique and its application to high precision measurement. I will especially describe in details how this method allows us to perform an atom recoil measurement at the level of $1.3 \\times 10^{-9}$. This measurement is used in the most precise determination of the fine structure constant that is independent of quantum electrodynamics.

  20. Application of fiber optic interferometers for Cook-off measurements

    NARCIS (Netherlands)

    Cheng, L.K.; Smorenburg, C.; Scholtes, J.H.G.; Meer, B.J. van der

    2000-01-01

    A fiber optic interferometer comprising of a Sagnac interferometer and a Mach-Zehnder interferometer was developed. The interferometer enabled detection of explosive subtonic expansion velocities during the Cook-off test. The system enabled a comparison between the results of the two interferometer

  1. Cryogenic Michelson Interferometer on the Space Shuttle

    OpenAIRE

    Wellard, Stan; Blakeley, Jeff; Brown, Steven; Bartschi, Brent

    1993-01-01

    A helium-cooled interferometer was flown aboard shuttle ifight STS-39. This interferometer, along with its sister radiometer, set new benchmarks for the quantity and quality of data collected. The interferometer generated approximately 150,000 interferograms during the course of the ifight. Data was collected at tangent heights from the earth's surface to celestial targets. The interferograms encoded spectral data from aurora, earth limb, and earth terminator scenes. The interfemmeter collect...

  2. The WIND-HAARP-HIPAS Interferometer Experiment

    Science.gov (United States)

    1999-04-22

    Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6750--99-8349 The WIND- HAARP -HIPAS Interferometer Experiment P. RODRIGUEZ AND M. J...1999 3. REPORT TYPE AND DATES COVERED Interim Report 4. TITLE AND SUBTITLE The WIND- HAARP -HIPAS Interferometer Experiment 5. FUNDING NUMBERS JO...frequency transmitting facilities in a bistatic, interferometer mode. The HAARP and HIPAS facilities in Alaska radiated at 4525 kHz with total combined

  3. Monolithically integrated interferometer for optical displacement measurement

    Science.gov (United States)

    Hofstetter, Daniel; Zappe, Hans P.

    1996-01-01

    We discuss the fabrication of a monolithically integrated optical displacement sensors using III-V semiconductor technology. The device is configured as a Michelson interferometer and consists of a distributed Bragg reflector laser, a photodetector and waveguides forming a directional coupler. Using this interferometer, displacements in the 100 nm range could be measured at distances of up to 45 cm. We present fabrication, device results and characterization of the completed interferometer, problems, limitations and future applications will also be discussed.

  4. Sangac interferometer on the holographic bragg grating

    CERN Document Server

    Tikhonov, E A

    2015-01-01

    The ring interferometer with zero optical path difference known as Sagnac one is offered with a diffraction splitting of the entering light beam. As the beamsplitter, a transmission holographic Bragg grating is used. Conditions of normal operation of this interferometer achieve under the equal intensity of beam copies and the adjustable phase shift between them in its two interferometer shoulders. These conditions are met with the holographic grating, which provides the phase shift 180^0 on the central Bragg wavelength. Experimental approbation of the modified interferometer validates the expected results.

  5. Controlling the Multiport Nature of Bragg Diffraction in Atom Interferometry

    CERN Document Server

    Parker, Richard H; Estey, Brian; Zhong, Weicheng; Huang, Eric; Müller, Holger

    2016-01-01

    Bragg diffraction has been used in atom interferometers because it allows signal enhancement through multiphoton momentum transfer and suppression of systematics by not changing the internal state of atoms. Its multi-port nature, however, can lead to parasitic interferometers, allows for intensity-dependent phase shifts in the primary interferometers, and distorts the ellipses used for phase extraction. We study and suppress these unwanted effects. Specifically, phase extraction by ellipse fitting and the resulting systematic phase shifts are calculated by Monte Carlo simulations. Phase shifts arising from the thermal motion of the atoms are controlled by spatial selection of atoms and an appropriate choice of Bragg intensity. In these simulations, we found that Gaussian Bragg pulse shapes yield the smallest systematic shifts. Parasitic interferometers are suppressed by a "magic" Bragg pulse duration. The sensitivity of the apparatus was improved by the addition of AC Stark shift compensation, which permits d...

  6. Long-term laser frequency stabilization using fiber interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Jia, E-mail: jia.kong@icfo.es [ICFO – Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona (Spain); Quantum Institute for Light and Atoms, Department of Physics, State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Lucivero, Vito Giovanni; Jiménez-Martínez, Ricardo [ICFO – Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona (Spain); Mitchell, Morgan W. [ICFO – Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona (Spain); ICREA – Institució Catalana de Recerca i Estudis Avançats, 08015 Barcelona (Spain)

    2015-07-15

    We report long-term laser frequency stabilization using only the target laser and a pair of 5 m fiber interferometers, one as a frequency reference and the second as a sensitive thermometer to stabilize the frequency reference. When used to stabilize a distributed feedback laser at 795 nm, the frequency Allan deviation at 1000 s drops from 5.6 × 10{sup −8} to 6.9 × 10{sup −10}. The performance equals that of an offset lock employing a second, atom-stabilized laser in the temperature control.

  7. Extending the Interaction Time of Linear and Ring-Shaped Condensate Interferometers

    Science.gov (United States)

    2011-09-06

    ADDRESSES U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS atom interferometry, Bose - Einstein condensate Charles...150403. doi: 09/01/2011 2.00 J. H. T. Burke, C. A. Sackett. Scalable Bose - Einstein - condensate Sagnac interferometer in a linear trap, Physical Review A...7.00 John Burke, Cass Sackett. Implementation of a Bose Einstein condensate gyroscope, 40th Annual Meeting of the APS Division of Atomic, Molecular

  8. Coherent matter wave optics on an atom chip

    DEFF Research Database (Denmark)

    Krüger, Peter; Hofferberth, S.; Schumm, Thorsten

    2006-01-01

    Coherent manipulation of matter waves in microscopic trapping potentials facilitates both fundamental and technological applications. Here we focus on experiments with a microscopic integrated interferometer that demonstrate coherent operation on an atom chip.......Coherent manipulation of matter waves in microscopic trapping potentials facilitates both fundamental and technological applications. Here we focus on experiments with a microscopic integrated interferometer that demonstrate coherent operation on an atom chip....

  9. Influence of the Coriolis force in atom interferometry.

    Science.gov (United States)

    Lan, Shau-Yu; Kuan, Pei-Chen; Estey, Brian; Haslinger, Philipp; Müller, Holger

    2012-03-01

    In a light-pulse atom interferometer, we use a tip-tilt mirror to remove the influence of the Coriolis force from Earth's rotation and to characterize configuration space wave packets. For interferometers with a large momentum transfer and large pulse separation time, we improve the contrast by up to 350% and suppress systematic effects. We also reach what is to our knowledge the largest space-time area enclosed in any atom interferometer to date. We discuss implications for future high-performance instruments.

  10. Improvement of an Atomic Clock using Squeezed Vacuum

    DEFF Research Database (Denmark)

    Kruse, I.; Lange, K; Peise, Jan

    2016-01-01

    Since the pioneering work of Ramsey, atom interferometers are employed for precision metrology, in particular to measure time and to realize the second. In a classical interferometer, an ensemble of atoms is prepared in one of the two input states, whereas the second one is left empty. In this case......, the vacuum noise restricts the precision of the interferometer to the standard quantum limit (SQL). Here, we propose and experimentally demonstrate a novel clock configuration that surpasses the SQL by squeezing the vacuum in the empty input state. We create a squeezed vacuum state containing an average of 0...

  11. Scalar Aharonov–Bohm Phase in Ramsey Atom Interferometry under Time-Varying Potential

    Directory of Open Access Journals (Sweden)

    Atsuo Morinaga

    2016-08-01

    Full Text Available In a Ramsey atom interferometer excited by two electromagnetic fields, if atoms are under a time-varying scalar potential during the interrogation time, the phase of the Ramsey fringes shifts owing to the scalar Aharonov–Bohm effect. The phase shift was precisely examined using a Ramsey atom interferometer with a two-photon Raman transition under the second-order Zeeman potential, and a formula for the phase shift was derived. Using the derived formula, the frequency shift due to the scalar Aharonov–Bohm effect in the frequency standards utilizing the Ramsey atom interferometer was discussed.

  12. In-fiber integrated Michelson interferometer

    Science.gov (United States)

    Yuan, Libo; Yang, Jun; Liu, Zhihai; Sun, Jiaxing

    2006-09-01

    A novel fiber-optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. It consists of a segment of two-core fiber with a mirrored fiber end. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core in-fiber integrated Michelson interferometer, are investigated.

  13. In-fiber integrated Michelson interferometer.

    Science.gov (United States)

    Yuan, Libo; Yang, Jun; Liu, Zhihai; Sun, Jiaxing

    2006-09-15

    A novel fiber-optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. It consists of a segment of two-core fiber with a mirrored fiber end. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core in-fiber integrated Michelson interferometer, are investigated.

  14. Heterodyne displacement interferometer, insensitive for input polarization

    NARCIS (Netherlands)

    Meskers, A.J.H.; Spronck, J.W.; Munnig Schmidt, R.H.

    2014-01-01

    Periodic nonlinearity (PNL) in displacement interferometers is a systematic error source that limits measurement accuracy. The PNL of coaxial heterodyne interferometers is highly influenced by the polarization state and orientation of the source frequencies. In this Letter, we investigate this error

  15. Graphic method for analyzing common path interferometers

    DEFF Research Database (Denmark)

    Glückstad, J.

    1998-01-01

    Common path interferometers are widely used for visualizing phase disturbances and fluid flows. They are attractive because of the inherent simplicity and robustness in the setup. A graphic method will be presented for analyzing and optimizing filter parameters in common path interferometers....

  16. Algorithms for Unequal-Arm Michelson Interferometers

    Science.gov (United States)

    Giampieri, Giacomo; Hellings, Ronald W.; Tinto, Massimo; Bender, Peter L.; Faller, James E.

    1994-01-01

    A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam.

  17. Interferometer Techniques for Gravitational-Wave Detection

    Directory of Open Access Journals (Sweden)

    Andreas Freise

    2010-02-01

    Full Text Available Several km-scale gravitational-wave detectors have been constructed world wide. These instruments combine a number of advanced technologies to push the limits of precision length measurement. The core devices are laser interferometers of a new kind; developed from the classical Michelson topology these interferometers integrate additional optical elements, which significantly change the properties of the optical system. Much of the design and analysis of these laser interferometers can be performed using well-known classical optical techniques, however, the complex optical layouts provide a new challenge. In this review we give a textbook-style introduction to the optical science required for the understanding of modern gravitational wave detectors, as well as other high-precision laser interferometers. In addition, we provide a number of examples for a freely available interferometer simulation software and encourage the reader to use these examples to gain hands-on experience with the discussed optical methods.

  18. Interferometer techniques for gravitational-wave detection

    Science.gov (United States)

    Bond, Charlotte; Brown, Daniel; Freise, Andreas; Strain, Kenneth A.

    2016-12-01

    Several km-scale gravitational-wave detectors have been constructed worldwide. These instruments combine a number of advanced technologies to push the limits of precision length measurement. The core devices are laser interferometers of a new kind; developed from the classical Michelson topology these interferometers integrate additional optical elements, which significantly change the properties of the optical system. Much of the design and analysis of these laser interferometers can be performed using well-known classical optical techniques; however, the complex optical layouts provide a new challenge. In this review, we give a textbook-style introduction to the optical science required for the understanding of modern gravitational wave detectors, as well as other high-precision laser interferometers. In addition, we provide a number of examples for a freely available interferometer simulation software and encourage the reader to use these examples to gain hands-on experience with the discussed optical methods.

  19. Impact of anomalous dispersion on the interferometer measurements of plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Nilsen, J; Johnson, W R; Iglesias, C A; Scofield, J H

    2004-12-16

    For many decades optical interferometers have been used to measure the electron density of plasmas. During the last ten years X-ray lasers in the wavelength range 14 to 47 nm have enabled researchers to use interferometers to probe even higher density plasmas. The data analysis assumes that the index of refraction is due only to the free electrons, which makes the index of refraction less than one and the electron density proportional to the number of fringe shifts. Recent experiments in Al plasmas observed plasmas with an index of refraction greater than one and made us question the validity of the usual formula for calculating the index of refraction. Recent calculations showed how the anomalous dispersion from the bound electrons can dominate the index of refraction in many types of plasma and make the index greater than one or enhance the index such that one would greatly overestimate the electron density of the plasma using interferometers. In this work we calculate the index of refraction of C, Al, Ti, and Pd plasmas for photon energies from 0 to 100 eV (12.4 nm) using a new average-atom code. The results show large variations from the free electron approximation under many different plasma conditions. We validate the average-atom code against the more detailed OPAL code for carbon and aluminum plasmas. During the next decade X-ray free electron lasers and other sources will be available to probe a wider variety of plasmas at higher densities and shorter wavelengths so understanding the index of refraction in plasmas will be even more essential.

  20. Dissipative optomechanics in a Michelson-Sagnac interferometer.

    Science.gov (United States)

    Xuereb, André; Schnabel, Roman; Hammerer, Klemens

    2011-11-18

    Dissipative optomechanics studies the coupling of the motion of an optical element to the decay rate of a cavity. We propose and theoretically explore a realization of this system in the optical domain, using a combined Michelson-Sagnac interferometer, which enables a strong and tunable dissipative coupling. Quantum interference in such a setup results in the suppression of the lower motional sideband, leading to strongly enhanced cooling in the non-sideband-resolved regime. With state-of-the-art parameters, ground-state cooling and low-power quantum-limited position transduction are both possible. The possibility of a strong, tunable dissipative coupling opens up a new route towards observation of such fundamental optomechanical effects as nonlinear dynamics. Beyond optomechanics, the suggested method can be readily transferred to other setups involving nonlinear media, atomic ensembles, or single atoms.

  1. Interferometer for measuring dynamic corneal topography

    Science.gov (United States)

    Micali, Jason Daniel

    The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface where the majority of refraction takes place in the eye. A significant component of vision quality is determined by the shape of the cornea and stability of the tear film. It is desirable to possess an instrument that can measure the corneal shape and tear film surface with the same accuracy and resolution that is currently performed on common optical elements. A dual interferometer system for measuring the dynamic corneal topography is designed, built, and verified. The completed system is validated by testing on human subjects. The system consists of two co-aligned polarization splitting Twyman-Green interferometers designed to measure phase instantaneously. The primary interferometer measures the surface of the tear film while the secondary interferometer simultaneously tracks the absolute position of the cornea. Eye motion, ocular variation, and a dynamic tear film surface will result in a non-null configuration of the surface with respect to the interferometer system. A non-null test results in significant interferometer induced errors that add to the measured phase. New algorithms are developed to recover the absolute surface topography of the tear film and corneal surface from the simultaneous interferometer measurements. The results are high-resolution and high-accuracy surface topography measurements of the in vivo cornea that are captured at standard camera frame rates. This dissertation will cover the development and construction of an interferometer system for measuring the dynamic corneal topography of the human eye. The discussion starts with the completion of an interferometer for measuring the tear film. The tear film interferometer is part of an

  2. Fizeau interferometer system for fast high resolution studies of spectral line shapes

    Energy Technology Data Exchange (ETDEWEB)

    Novak, O. [School of Physics A28, University of Sydney, Sydney, NSW 2006 (Australia); Department of Physics, University of West Bohemia, Univerzitni 22, 30614 Plzen (Czech Republic); Falconer, I. S.; Sangines, R.; Tarrant, R. N.; McKenzie, D. R.; Bilek, M. M. M. [School of Physics A28, University of Sydney, Sydney, NSW 2006 (Australia); Lattemann, M. [School of Physics A28, University of Sydney, Sydney, NSW 2006 (Australia); Joint Research Laboratory Nanomaterials, Technische Universitaet Darmstadt and Karlsruhe Institute of Technology (KIT), 64287 Darmstadt (Germany); Institut fuer Nanotechnologie, Karlsruhe Institute of Technology (KIT), Postfach 3640, 76021 Karlsruhe (Germany)

    2011-02-15

    A monochromator/Fizeau interferometer/intensified CCD camera system is described that was developed for the measurement of the shape of spectral lines that are rapidly time varying. The most important operating parameter that determines the performance of the instrument is the size of the entrance aperture as this determines both the light throughput and the effective interferometer wavelength resolution. This paper discusses, both theoretically and experimentally, the effect of the finite source area on the instrumental resolution to assist in optimizing the choice of this parameter. A second effect that often produces a practical limit to the quality of the spectra is drift of the interferometer plates. Measurements of the shapes of spectral lines of ions and atoms ejected from the cathode spot of continuous and pulsed cathodic arcs are presented to demonstrate the utility of this instrument.

  3. A Gravitational Wave Detector Based on an Atom Interferometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Gravitational waves are tiny perturbations in the curvature of space-time that arise from accelerating masses – according to Einstein’s general...

  4. Interferometer predictions with triangulated images

    DEFF Research Database (Denmark)

    Brinch, Christian; Dullemond, C. P.

    2014-01-01

    Interferometers play an increasingly important role for spatially resolved observations. If employed at full potential, interferometry can probe an enormous dynamic range in spatial scale. Interpretation of the observed visibilities requires the numerical computation of Fourier integrals over...... the synthetic model images. To get the correct values of these integrals, the model images must have the right size and resolution. Insufficient care in these choices can lead to wrong results. We present a new general-purpose scheme for the computation of visibilities of radiative transfer images. Our method...... requires a model image that is a list of intensities at arbitrarily placed positions on the image-plane. It creates a triangulated grid from these vertices, and assumes that the intensity inside each triangle of the grid is a linear function. The Fourier integral over each triangle is then evaluated...

  5. Handheld ESPI-speckle interferometer

    DEFF Research Database (Denmark)

    Skov Hansen, René

    2003-01-01

    reference. The reference wave is established by reflecting a part of the diffuse object illumination from a glass plate located just in front of the object. The glass plate is mounted on a piezoelectric translator in order to control the phase of the reference wave when using phase stepping algorithms....... The coherent light source is a laser diode. A web camera with a Universal Serial Bus (USB) interface is employed as the image-capturing device. Likewise, is the piezoelectric translator controlled through the USB interface. The necessary size of the optical set-up depends on the size of the object....... The interferometer presented here is a compact version of the set-up, Which is capable of measuring displacements of small objects, having either a specularly reflecting-or a diffusely scattering surface. The small optical set-up together with the use of the popular USB-communication for acquiring the images...

  6. Thermal Conductance of Andreev Interferometers

    Science.gov (United States)

    Jiang, Z.; Chandrasekhar, V.

    2005-04-01

    We calculate the thermal conductance GT of diffusive Andreev interferometers, which are hybrid loops with one superconducting arm and one normal-metal arm. The presence of the superconductor suppresses GT; however, unlike a conventional superconductor, GT/GTN does not vanish as the temperature T→0, but saturates at a finite value that depends on the resistance of the normal-superconducting interfaces, and their distance from the path of the temperature gradient. The reduction of GT is determined primarily by the suppression of the density of states in the proximity-coupled normal metal along the path of the temperature gradient. GT is also a strongly nonlinear function of the thermal current, as found in recent experiments.

  7. Multiple spacecraft Michelson stellar interferometer

    Science.gov (United States)

    Stachnik, R. V.; Arnold, D.; Melroy, P.; Mccormack, E. F.; Gezari, D. Y.

    1984-01-01

    Results of an orbital analysis and performance assessment of SAMSI (Spacecraft Array for Michelson Spatial Interferometry) are presented. The device considered includes two one-meter telescopes in orbits which are identical except for slightly different inclinations; the telescopes achieve separations as large as 10 km and relay starlight to a central station which has a one-meter optical delay line in one interferometer arm. It is shown that a 1000-km altitude, zero mean inclination orbit affords natural scanning of the 10-km baseline with departures from optical pathlength equality which are well within the corrective capacity of the optical delay line. Electric propulsion is completely adequate to provide the required spacecraft motions, principally those needed for repointing. Resolution of 0.00001 arcsec and magnitude limits of 15 to 20 are achievable.

  8. Sagnac interferometry with a single atomic clock

    CERN Document Server

    Stevenson, R; Bishop, T; Lesanovsky, I; Fernholz, T

    2015-01-01

    We theoretically discuss an implementation of a Sagnac interferometer with cold atoms. In contrast to currently existing schemes our protocol does not rely on any free propagation of atoms. Instead it is based on superpositions of fully confined atoms and state-dependent transport along a closed path. Using Ramsey sequences for an atomic clock, the accumulated Sagnac phase is encoded in the resulting population imbalance between two internal (clock) states. Using minimal models for the above protocol we analytically quantify limitations arising from atomic dynamics and finite temperature. We discuss an actual implementation of the interferometer with adiabatic radio-frequency potentials that is inherently robust against common mode noise as well as phase noise from the reference oscillator.

  9. Atom-interferometric measurement of Stark level splittings

    CERN Document Server

    Wang, Limei; Zhang, Linjie; Raithel, Georg; Zhao, Jianming; Jia, Suotang

    2015-01-01

    Multiple adiabatic/diabatic passages through avoided crossings in the Stark map of cesium Rydberg atoms are employed as beam splitters and recombiners in an atom-interferometric measurement of energy-level splittings. We subject cold cesium atoms to laser-excitation, electric-field and detection sequences that constitute an (internal-state) atom interferometer. For the read-out of the interferometer we utilize state-dependent collisions, which selectively remove atoms of one kind from the detected signal. We investigate the dependence of the interferometric signal on timing and field parameters, and find good agreement with time-dependent quantum simulations of the interferometer. Fourier analysis of the interferometric signals yield coherence frequencies that agree with corresponding energy-level differences in calculated Stark maps. The method enables spectroscopy of states that are inaccessible to direct laser-spectroscopic observation, due to selection rules, and has applications in field metrology.

  10. Prospects for Precise Measurements with Echo Atom Interferometry

    Directory of Open Access Journals (Sweden)

    Brynle Barrett

    2016-06-01

    Full Text Available Echo atom interferometers have emerged as interesting alternatives to Raman interferometers for the realization of precise measurements of the gravitational acceleration g and the determination of the atomic fine structure through measurements of the atomic recoil frequency ω q . Here we review the development of different configurations of echo interferometers that are best suited to achieve these goals. We describe experiments that utilize near-resonant excitation of laser-cooled rubidium atoms by a sequence of standing wave pulses to measure ω q with a statistical uncertainty of 37 parts per billion (ppb on a time scale of ∼50 ms and g with a statistical precision of 75 ppb. Related coherent transient techniques that have achieved the most statistically precise measurements of atomic g-factor ratios are also outlined. We discuss the reduction of prominent systematic effects in these experiments using off-resonant excitation by low-cost, high-power lasers.

  11. Prospects for Precise Measurements with Echo Atom Interferometry

    CERN Document Server

    Barrett, Brynle; Beica, Hermina C; Vorozcovs, Andrejs; Pouliot, Alexander; Kumarakrishnan, A

    2016-01-01

    Echo atom interferometers have emerged as interesting alternatives to Raman interferometers for the realization of precise measurements of the gravitational acceleration $g$ and the determination of the atomic fine structure through measurements of the atomic recoil frequency $\\omega_q$. Here we review the development of different configurations of echo interferometers that are best suited to achieve these goals. We describe experiments that utilize near-resonant excitation of laser-cooled rubidium atoms by a sequence of standing wave pulses to measure $\\omega_q$ with a statistical uncertainty of 37 parts per billion (ppb) on a time scale of $\\sim 50$ ms and $g$ with a statistical precision of 75 ppb. Related coherent transient techniques that have achieved the most statistically precise measurements of atomic g-factor ratios are also outlined. We discuss the reduction of prominent systematic effects in these experiments using off-resonant excitation by low-cost, high-power lasers.

  12. Cold-atom Inertial Sensor without Deadtime

    CERN Document Server

    Fang, Bess; Savoie, Denis; Venon, Bertrand; Alzar, Carlos L Garrido; Geiger, Remi; Landragin, Arnaud

    2016-01-01

    We report the operation of a cold-atom inertial sensor in a joint interrogation scheme, where we simultaneously prepare a cold-atom source and operate an atom interferometer in order to eliminate dead times. Noise aliasing and dead times are consequences of the sequential operation which is intrinsic to cold-atom atom interferometers. Both phenomena have deleterious effects on the performance of these sensors. We show that our continuous operation improves the short-term sensitivity of atom interferometers, by demonstrating a record rotation sensitivity of $100$ nrad.s$^{-1}/\\sqrt{\\rm Hz}$ in a cold-atom gyroscope of $11$ cm$^2$ Sagnac area. We also demonstrate a rotation stability of $1$ nrad.s$^{-1}$ after $10^4$ s of integration, improving previous results by an order of magnitude. We expect that the continuous operation will allow cold-atom inertial sensors with long interrogation time to reach their full sensitivity, determined by the quantum noise limit.

  13. An Atomic Gravitational Wave Interferometric Sensor (AGIS)

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Savas; /Stanford U., Phys. Dept.; Graham, Peter W.; /SLAC; Hogan, Jason M.; Kasevich, Mark A.; /Stanford U., Phys. Dept.; Rajendran, Surjeet; /SLAC /Stanford U., Phys. Dept.

    2008-08-01

    We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of the Stanford 10m atom interferometer presently under construction. Each configuration compares two widely separated atom interferometers run using common lasers. The signal scales with the distance between the interferometers, which can be large since only the light travels over this distance, not the atoms. The terrestrial experiment with baseline {approx} 1 km can operate with strain sensitivity {approx} 10{sup -19}/{radical}Hz in the 1 Hz-10 Hz band, inaccessible to LIGO, and can detect gravitational waves from solar mass binaries out to megaparsec distances. The satellite experiment with baseline {approx} 1000 km can probe the same frequency spectrum as LISA with comparable strain sensitivity {approx} 10{sup -20}/{radical}Hz. The use of ballistic atoms (instead of mirrors) as inertial test masses improves systematics coming from vibrations, acceleration noise, and significantly reduces spacecraft control requirements. We analyze the backgrounds in this configuration and discuss methods for controlling them to the required levels.

  14. Double-grating interferometer with a one-to-one correspondence with a Michelson interferometer.

    Science.gov (United States)

    Xu, Yande; Sasaki, Osami; Suzuki, Takamasa

    2003-10-01

    We describe a double-grating interferometer that has a one-to-one correspondence with a Michelson interferometer. The half spatial periods of the gratings are equivalent to the wavelengths of the interferometer. The widths of the interference fringes can be changed easily. The intensity distribution of the interference pattern is independent of the wavelength of the light source used. The surface profile of an object can be measured because two interference beams can coincide precisely on the image plane of the object. The measuring range is much larger than that of a Michelson interferometer.

  15. An Optimal Design for Universal Multiport Interferometers

    CERN Document Server

    Clements, William R; Metcalf, Benjamin J; Kolthammer, W Steven; Walmsley, Ian A

    2016-01-01

    Universal multiport interferometers, which can be programmed to implement any linear transformation between multiple channels, are emerging as a powerful tool for both classical and quantum photonics. These interferometers are typically composed of a regular mesh of beam splitters and phase shifters, allowing for straightforward fabrication using integrated photonic architectures and ready scalability. The current, standard design for universal multiport interferometers is based on work by Reck et al (Phys. Rev. Lett. 73, 58, 1994). We demonstrate a new design for universal multiport interferometers based on an alternative arrangement of beam splitters and phase shifters, which outperforms that by Reck et al. Our design occupies half the physical footprint of the Reck design and is significantly more robust to optical losses.

  16. Improved double-pass michelson interferometer

    Science.gov (United States)

    Schindler, R. A.

    1978-01-01

    Interferometer design separates beams by offsetting centerlines of cat's-eye retroreflectors vertically rather than horizontally. Since beam splitter is insensitive to minimum-thickness condition in this geometry, relatively-low-cost, optically flat plate can be used.

  17. Naturally stable Sagnac-Michelson nonlinear interferometer

    Science.gov (United States)

    Lukens, Joseph M.; Peters, Nicholas A.; Pooser, Raphael C.

    2016-12-01

    Interferometers measure a wide variety of dynamic processes by converting a phase change into an intensity change. Nonlinear interferometers, making use of nonlinear media in lieu of beamsplitters, promise substantial improvement in the quest to reach the ultimate sensitivity limits. Here we demonstrate a new nonlinear interferometer utilizing a single parametric amplifier for mode mixing---conceptually, a nonlinear version of the conventional Michelson interferometer with its arms collapsed together. We observe up to 99.9\\% interference visibility and find evidence for noise reduction based on phase-sensitive gain. Our configuration utilizes fewer components than previous demonstrations and requires no active stabilization, offering new capabilities for practical nonlinear interferometric-based sensors.

  18. The effect of rotations on Michelson interferometers

    Science.gov (United States)

    Maraner, Paolo

    2014-11-01

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer's speed to the speed of light, further suppressed by the ratio of the interferometer's arms length to the radius of rotation and depends on the interferometer's position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth's rotated kilometer-scale Fabry-Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations.

  19. Optical Fiber Bragg Grating Michelson Interferometer

    Institute of Scientific and Technical Information of China (English)

    JIANG Yi; JIANG Tian-fu; LIU Li

    2006-01-01

    A new Michelson interferometer based on fiber Bragg grating(FBG) is demonstrated. FBGs are used as reflectors, and the laser is replaced by a broadband source as input light in this interferometer. To demodulate the signals, a 3×3 coupler is used as a splitter. By combining with software demodulation, the outer inter ference can be obtained from the outputs of the interferometer. This kind of in terferometer can also be wavelength-multiplexed easily by composing a series Michelson interferometer. The experiment results show that the clear interference fringe can be obtained by adjusting the path difference to make it less than interference length of FBG. The signals are also demodulated.

  20. Interferometer measurements in pulsed plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lisitsyn, I.V.; Kohno, Susumu; Kawauchi, Toshinori; Sueda, Tsuyoshi; Katsuki, Sunao; Akiyama, Hidenori [Kumamoto Univ. (Japan). Faculty of Engineering

    1997-11-01

    The interferometer measurements are extremely informative in plasma experiments allowing direct evaluations of the electron density. The primary goal of the work presented, is to build a laser interferometer which meets the requirements of the highest possible simplicity, economy, convenience and ease of construction. These requirements are successfully satisfied while maintaining high sensitivity ({+-}0.5deg - of phase shift) and a wide density range (10{sup 14} and 10{sup 19} cm{sup -2} - line-integrated) of the interferometer. In our experiments we used a low average power (5 mW) He-Ne laser without complicated and costly stabilization or detection environments. The He-Ne laser interferometer with the Michelson arrangement was used to measure the line-integrated plasma densities in various plasma experiments. Time- and spatially-resolved density measurements were performed for a plasma opening switch, a laser produced plasma, an electrothermal launcher and railgun plasmas. (author)

  1. Step index fibre using laser interferometer

    Indian Academy of Sciences (India)

    A M Hamed

    2014-03-01

    model is suggested to describe the fringe shift which occurs due to the phase variations of cladded glass fibre introduced between the two plates of the liquid wedge interferometer illuminated with a He–Ne laser. The fringe shift of the phase object which appears in the denominator of the Airy distribution formula of the multiple beam interference is represented in the harmonic term. An experiment is conducted using liquid wedge interferometer where the step index glass fibre of a nearly quadratic thickness variation is introduced between the two plates of the interferometer. The obtained fringe shift shows a good agreement with the proposed quadratic model. The Matlab code is written to plot the interferometer fringes comprising the shift of the step index fibre. Secondly, recognition of elliptical fibres is outlined using tomographic imaging. Finally, results and concluding remarks are given.

  2. Large-Area Atom Interferometry with Frequency-Swept Raman Adiabatic Passage.

    Science.gov (United States)

    Kotru, Krish; Butts, David L; Kinast, Joseph M; Stoner, Richard E

    2015-09-04

    We demonstrate light-pulse atom interferometry with large-momentum-transfer atom optics based on stimulated Raman transitions and frequency-swept adiabatic rapid passage. Our atom optics have produced momentum splittings of up to 30 photon recoil momenta in an acceleration-sensitive interferometer for laser cooled atoms. We experimentally verify the enhancement of phase shift per unit acceleration and characterize interferometer contrast loss. By forgoing evaporative cooling and velocity selection, this method lowers the atom shot-noise-limited measurement uncertainty and enables large-area atom interferometry at higher data rates.

  3. Laser in-cavity Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, C.M.

    1978-09-01

    A new laser interferometer is proposed which can be regarded as an in-cavity Michelson interferometer. It utilizes a polarizing beam splitter in conjunction with two quarter-wave plates to produce oscillations between three mirrors. It would measure a change in length of 10/sup -3/ A that, if used for plasma diagnostics, is equivalent to measuring an electron density of 10/sup 9/ cm/sup -3/ over a plasma length of 1 cm.

  4. Nonlinear Michelson interferometer for improved quantum metrology

    Science.gov (United States)

    Luis, Alfredo; Rivas, Ángel

    2015-08-01

    We examine quantum detection via a Michelson interferometer embedded in a gas with Kerr nonlinearity. This nonlinear interferometer is illuminated by pulses of classical light. This strategy combines the robustness against practical imperfections of classical light with the improvement provided by nonlinear processes. Regarding ultimate quantum limits, we stress that, as a difference with linear schemes, the nonlinearity introduces pulse duration as a new variable into play along with the energy resources.

  5. Nonlinear Michelson interferometer for improved quantum metrology

    OpenAIRE

    Luis Aina, Alfredo; Rivas Vargas, Ángel

    2015-01-01

    We examine quantum detection via a Michelson interferometer embedded in a gas with Kerr nonlinearity. This nonlinear interferometer is illuminated by pulses of classical light. This strategy combines the robustness against practical imperfections of classical light with the improvement provided by nonlinear processes. Regarding ultimate quantum limits, we stress that, as a difference with linear schemes, the nonlinearity introduces pulse duration as a new variable into play along with the ene...

  6. The VLA Atmospheric Phase Interferometer

    Science.gov (United States)

    Morris, Keith

    2014-05-01

    The Atmospheric Phase Interferometer (API) is a two-element atmospheric seeing monitor located at the Very Large Array (VLA) site. The instrument measures turbulent refractive index variation through the atmosphere by examining phase differences in a satellite beacon signal detected at two (or more) antennas. With this measurement, the VLA scheduling software is able to consider atmospheric stability when determining which frequency observation to schedule next. We are in the process of extending this two-element interferometer to four elements, which will allow us to measure the turbulence in two dimensions and at multiple length scales. This thesis will look at some statistical properties of turbulence, the effects of atmospheric stability on radio interferometric observations, and discuss details of the instrument and the data that it collects. The thesis will also cover some techniques and principles of signal processing, and an analysis of some data from the instrument. The results demonstrate that other surface atmospheric variables (e.g. windspeed, water vapor pressure) show the same structure function exponent as the atmospheric phase fluctuations. In particular, the structure functions of water vapor partial pressure and wind speed show the same exponent as the phase. Though the agreement between meteorological variables and atmospheric phase is scientifically satisfying, these surface measurements are not nearly as sensitive as the API saturation phase measurement, and therefore cannot be used to schedule telescope time in its stead. What is informative about these results is that the similar structure functions for API and meteorological data are detecting reinforce the claim that both measurements represent turbulent transport, and not instrumental noise. Data from the instrument reveals that measurements are consistent with both Kolmogorov turbulence theory, and with prior observations. The API predominately measures three-dimensional isotropic

  7. Suspension of atoms using optical pulses, and application to gravimetry.

    Science.gov (United States)

    Hughes, K J; Burke, J H T; Sackett, C A

    2009-04-17

    Atoms from a (87)Rb condensate are suspended against gravity using repeated reflections from a pulsed optical standing wave. Up to 100 reflections are observed, yielding suspension times of over 100 ms. The local gravitational acceleration can be determined from the pulse rate required to achieve suspension. Further, a gravitationally sensitive atom interferometer was implemented using the suspended atoms. This technique could potentially provide a precision measurement of gravity without requiring the atoms to fall a large distance.

  8. Towards a matter wave interferometer on a sounding rocket

    Science.gov (United States)

    van Zoest, Tim; Peters, Achim; Ahlers, Holger; Wicht, Andreas; Vogel, Anika; Wenzlawski, Anderas; Deutsch, Christian; Kajari, Endre; Gaaloul, Naceur; Dittus, Hansjürg; Hartwig, Jonas; Herr, Waldemar; Herrmann, Sven; Reichel, Jakob; Bongs, Kai; Koenemann, Thorben; Laemmerzahl, Claus; Lewoczko-Adamczyk, Wojtek; Schiemangk, Max; Müntinga, Hauke; Meyer, Nadine; Rasel, Ernst Maria; Walser, Reinhold; Resch, Andreas; Rode, Christina; Seidel, Stephan; Sengstock, Klaus; Singh, Yeshpal; Schleich, Wolfgang; Ertmer, Wolfgang; Rosenbusch, Peter; Wilken, Tobias; Goeklue, Ertan

    Applications of coherent matter waves are high resolution interferometers for measuring inertial and gravitational forces as well as testing fundamental physics, for which they may serve as a laser like source with mesoscopic quantum features. Out of possible applications, the test of the principle of equivalence in the quantum domain is selected as a target with the highest scientific interest on timescales of a microgravity experiment at the ISS or on a free flyer (ATV, FOTON or other satellites). The QUANTUS project demonstrated the technological feasibil-ity of coherent matter waves in microgravity. As a next step, the consortium will prepare and procure a sounding rocket mission to demonstrate technologies for matter wave interferome-try based on the broad experience of former developments with experiments in the droptower. Therefore, the experiment has to withstand strong requirements concerning environmental con-ditions (Temperature, shock, environmental pressure, etc.) and needs to be designed to fit in a 600 l volume (diameter 35 cm, length 160 cm). It is considered as an important step towards the technology required for the ISS and other platforms. These experiments will give further insights on the potential of inertial sensors based on atom interferometers and the technology is for example of interest for applications in earth observation and geodesy. They could replace classical techniques relying on test masses and promise a further improvement in the accuracy of such devices.

  9. Cold atom quantum sensors for space

    Science.gov (United States)

    Singh, Yeshpal

    2016-07-01

    Quantum sensors based on cold atoms offer the opportunity to perform highly accurate measurements of physical phenomena related to time, gravity and rotation. The deployment of such technologies in the microgravity environment of space may enable further enhancement of their performance, whilst permitting the detection of these physical phenomena over much larger scales than is possible with a ground-based instrument. In this talk, I will present an overview of the activities of the UK National Quantum Hub in Sensors and Metrology in developing cold atoms technology for space. Our activities are focused in two main areas: optical clocks and atom interferometers. I will also discuss our contributions to recent initiatives including STE-QUEST and AI-GOAT, the ESA/NASA initiative aiming at an atom interferometer gravitational wave detector in space.

  10. Precision Gravity Tests with Atom Interferometry in Space

    Science.gov (United States)

    Tino, G. M.; Sorrentino, F.; Aguilera, D.; Battelier, B.; Bertoldi, A.; Bodart, Q.; Bongs, K.; Bouyer, P.; Braxmaier, C.; Cacciapuoti, L.; Gaaloul, N.; Gürlebeck, N.; Hauth, M.; Herrmann, S.; Krutzik, M.; Kubelka, A.; Landragin, A.; Milke, A.; Peters, A.; Rasel, E. M.; Rocco, E.; Schubert, C.; Schuldt, T.; Sengstock, K.; Wicht, A.

    2013-10-01

    Atom interferometry provides extremely sensitive and accurate tools for the measurement of inertial forces. Operation of atom interferometers in microgravity is expected to enhance the performance of such sensors. This paper presents two possible implementations of a dual 85Rb-87Rb atom interferometer to perform differential gravity measurements in space, with the primary goal to test the Weak Equivalence Principle. The proposed scheme is in the framework of two projects of the European Space Agency, namely Q-WEP and STE-QUEST. The paper describes the baseline experimental configuration, and discusses the technology readiness, noise and error budget for the two proposed experiments.

  11. Precision Gravity Tests with Atom Interferometry in Space

    Energy Technology Data Exchange (ETDEWEB)

    Tino, G.M.; Sorrentino, F. [Dipartimento di Fisica e Astronomia and LENS, Università di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); Aguilera, D. [Institute of Space Systems, German Aerospace Center, Robert-Hooke-Strasse 7, 28359 Bremen (Germany); Battelier, B.; Bertoldi, A. [Laboratoire Photonique, Numérique et Nanosciences, LP2N - UMR5298 - IOGS - CNRS Université Bordeaux 1, Bâtiment A30 351 cours de la Libération F-33405 TALENCE Cedex France (France); Bodart, Q. [Dipartimento di Fisica e Astronomia and LENS, Università di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); Bongs, K. [Midlands Ultracold Atom Research Centre School of Physics and Astronomy University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Bouyer, P. [Laboratoire Photonique, Numérique et Nanosciences, LP2N - UMR5298 - IOGS - CNRS Université Bordeaux 1, Bâtiment A30 351 cours de la Libération F-33405 TALENCE Cedex France (France); Braxmaier, C. [Institute of Space Systems, German Aerospace Center, Robert-Hooke-Strasse 7, 28359 Bremen (Germany); Cacciapuoti, L. [European Space Agency, Research and Scientific Support Department, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Gaaloul, N. [Institute of Quantum Optics, Leibniz Universitaet Hannover, Welfengarten 1, D 30167 Hannover (Germany); Gürlebeck, N. [University of Bremen, Centre of Applied Space Technology and Microgravity (ZARM), Am Fallturm, D - 29359 Bremen (Germany); Hauth, M. [Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489 Berlin (Germany); and others

    2013-10-15

    Atom interferometry provides extremely sensitive and accurate tools for the measurement of inertial forces. Operation of atom interferometers in microgravity is expected to enhance the performance of such sensors. This paper presents two possible implementations of a dual {sup 85}Rb-{sup 87}Rb atom interferometer to perform differential gravity measurements in space, with the primary goal to test the Weak Equivalence Principle. The proposed scheme is in the framework of two projects of the European Space Agency, namely Q-WEP and STE-QUEST. The paper describes the baseline experimental configuration, and discusses the technology readiness, noise and error budget for the two proposed experiments.

  12. Improvement of an Atomic Clock using Squeezed Vacuum

    DEFF Research Database (Denmark)

    Kruse, I.; Lange, K; Peise, Jan;

    2016-01-01

    , the vacuum noise restricts the precision of the interferometer to the standard quantum limit (SQL). Here, we propose and experimentally demonstrate a novel clock configuration that surpasses the SQL by squeezing the vacuum in the empty input state. We create a squeezed vacuum state containing an average of 0.......75 atoms to improve the clock sensitivity of 10000 atoms by 2.05+0.34−0.37  dB. The SQL poses a significant limitation for today’s microwave fountain clocks, which serve as the main time reference. We evaluate the major technical limitations and challenges for devising a next generation of fountain clocks......Since the pioneering work of Ramsey, atom interferometers are employed for precision metrology, in particular to measure time and to realize the second. In a classical interferometer, an ensemble of atoms is prepared in one of the two input states, whereas the second one is left empty. In this case...

  13. Concept of an ionizing time-domain matter-wave interferometer

    OpenAIRE

    Nimmrichter, Stefan; Haslinger, Philipp; Hornberger, Klaus; ARNDT, Markus

    2011-01-01

    We discuss the concept of an all-optical and ionizing matter-wave interferometer in the time domain. The proposed setup aims at testing the wave nature of highly massive clusters and molecules, and it will enable new precision experiments with a broad class of atoms, using the same laser system. The propagating particles are illuminated by three pulses of a standing ultraviolet laser beam, which detaches an electron via efficient single photon-absorption. Optical gratings may have periods as ...

  14. Large momentum beamsplitting in atom interferometry

    Institute of Scientific and Technical Information of China (English)

    G; D; McDonald; P; M; anju; P; B; Wigley; P; J; Everitt; WEI; Chunhua; M; A; Sooriyabandara; M; Boozarjmehr; A; Kordbacheh; C; Quinlivan; C; N; Kuhn; J; E; Debs; K; S; Hardman; N; P; Robins

    2015-01-01

    Large momentum transfer( LM T) beamsplitting in atom interferometry is review ed,focusing on the use of Bloch Oscillations to achieve high momentum separation w ithout loss of visibility. Phase sensitivity w ith a fringe visibility of 7% is observed in a horizontally guided,acceleration-sensitive atom interferometer w ith a momentum separation of 80k betw een its arms.In addition,a 510 k beamsplitter is demonstrated.

  15. Interacting Atomic Interferometry for Rotation Sensing Approaching the Heisenberg Limit

    Science.gov (United States)

    Ragole, Stephen; Taylor, Jacob M.

    2016-11-01

    Atom interferometers provide exquisite measurements of the properties of noninertial frames. While atomic interactions are typically detrimental to good sensing, efforts to harness entanglement to improve sensitivity remain tantalizing. Here we explore the role of interactions in an analogy between atomic gyroscopes and SQUIDs, motivated by recent experiments realizing ring-shaped traps for ultracold atoms. We explore the one-dimensional limit of these ring systems with a moving weak barrier, such as that provided by a blue-detuned laser beam. In this limit, we employ Luttinger liquid theory and find an analogy with the superconducting phase-slip qubit, in which the topological charge associated with persistent currents can be put into superposition. In particular, we find that strongly interacting atoms in such a system could be used for precision rotation sensing. We compare the performance of this new sensor to an equivalent noninteracting atom interferometer, and find improvements in sensitivity and bandwidth beyond the atomic shot-noise limit.

  16. Interferometric laser cooling of atomic rubidium

    CERN Document Server

    Dunning, Alexander; Bateman, James; Himsworth, Matthew; Freegarde, Tim

    2014-01-01

    We report the 1-D cooling of atoms using a velocity-dependent optical force based upon Ramsey matter-wave interferometry. The interferometer is realised with stimulated Raman transitions between ground hyperfine states, and after 12 cycles of the cooling sequence, we observe a reduction in the temperature of a freely moving cloud of magneto-optically cooled $^{85}$Rb atoms from 20 $\\mu$K to 4 $\\mu$K, accompanied in this first demonstration by an acceleration of the centre of mass of the atom cloud. This pulse-based laser cooling technique could in principle be extended to molecules and atoms that lack a closed radiative transition.

  17. Ramsey interferometry with an atom laser.

    Science.gov (United States)

    Döring, D; Debs, J E; Robins, N P; Figl, C; Altin, P A; Close, J D

    2009-11-09

    We present results on a free-space atom interferometer operating on the first order magnetically insensitive |F = 1,mF = 0) --> |F = 2,mF = 0) ground state transition of Bose-condensed (87)Rb atoms. A pulsed atom laser is output-coupled from a Bose-Einstein condensate and propagates through a sequence of two internal state beam splitters, realized via coherent Raman transitions between the two interfering states. We observe Ramsey fringes with a visibility close to 100% and determine the current and the potentially achievable interferometric phase sensitivity. This system is well suited to testing recent proposals for generating and detecting squeezed atomic states.

  18. Quadrature phase interferometer for high resolution force spectroscopy

    CERN Document Server

    Paolino, Pierdomenico; Bellon, Ludovic

    2013-01-01

    In this article, we present a deflection measurement setup for Atomic Force Microscopy (AFM). It is based on a quadrature phase differential interferometer: we measure the optical path difference between a laser beam reflecting above the cantilever tip and a reference beam reflecting on the static base of the sensor. A design with very low environmental susceptibility and another allowing calibrated measurements on a wide spectral range are described. Both enable a very high resolution (down to $2.5E-15 m/sqrt{Hz}$), illustrated by a thermal noise measurement on an AFM cantilever. A quick review shows that our precision is equaling or outperforming the best results reported in the literature, but for a much larger deflection range, up to a few microns.

  19. Michelson interferometer based spatial phase shift shearography.

    Science.gov (United States)

    Xie, Xin; Yang, Lianxiang; Xu, Nan; Chen, Xu

    2013-06-10

    This paper presents a simple spatial phase shift shearography based on the Michelson interferometer. The Michelson interferometer based shearographic system has been widely utilized in industry as a practical nondestructive test tool. In the system, the Michelson interferometer is used as a shearing device to generate a shearing distance by tilting a small angle in one of the two mirrors. In fact, tilting the mirror in the Michelson interferometer also generates spatial frequency shift. Based on this feature, we introduce a simple Michelson interferometer based spatial phase shift shearography. The Fourier transform (FT) method is applied to separate the spectrum on the spatial frequency domain. The phase change due to the loading can be evaluated using a properly selected windowed inverse-FT. This system can generate a phase map of shearography by using only a single image. The effects of shearing angle, spatial resolution of couple charge device camera, and filter methods are discussed in detail. The theory and the experimental results are presented.

  20. The AEI 10 m prototype interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Gossler, S; Bertolini, A; Born, M; Dahl, K; Kranz, O; Lueck, H; Schnabel, R; Wanner, A; Westphal, T [Leibniz Universitaet Hannover, D-30167 Hannover (Germany); Chen, Y; Somiya, K [California Institute of Technology, Theoretical Astrophysics 130-33, Pasadena, CA 91125 (United States); Gering, D; Graef, C; Heinzel, G; Kawazoe, F; Kuehn, G; Mossavi, K; Taylor, J R [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik, D-30167 Hannover (Germany); Hild, S; Strain, K A, E-mail: stefan.gossler@aei.mpg.d [University of Glasgow, Glasgow, G12 8QQ (United Kingdom)

    2010-04-21

    A 10 m prototype interferometer facility is currently being set up at the AEI in Hannover, Germany. The prototype interferometer will be housed inside a 100 m{sup 3} ultra-high vacuum envelope. Seismically isolated optical tables inside the vacuum system will be interferometrically interconnected via a suspension platform interferometer. Advanced isolation techniques will be used, such as inverted pendulums and geometrical anti-spring filters in combination with multiple-cascaded pendulum suspensions, containing an all-silica monolithic last stage. The light source is a 35 W Nd:YAG laser, geometrically filtered by passing it through a photonic crystal fibre and a rigid pre-modecleaner cavity. Laser frequency stabilisation will be achieved with the aid of a high finesse suspended reference cavity in conjunction with a molecular iodine reference. Coating thermal noise will be reduced by the use of Khalili cavities as compound end mirrors. Data acquisition and control of the experiments is based on the AdvLIGO digital control and data system. The aim of the project is to test advanced techniques for GEO 600 as well as to conduct experiments in macroscopic quantum mechanics. Reaching standard quantum-limit sensitivity for an interferometer with 100 g mirrors and subsequently breaching this limit, features most prominently among these experiments. In this paper we present the layout and current status of the AEI 10 m Prototype Interferometer project.

  1. Perfect crystal interferometer and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Yuji [Atominstitut der Oesterreichischen Universitaeten, Vienna (Austria)

    1996-08-01

    The interferometry with angstrom scale wavelength has developed steadily, and various types of interferometers have been investigated. Among them, LLL interferometers are widely used. The first neutron interferometry was achieved in 1962 by Maier-Leibnitz et al. A new type of neutron interferometers was constructed with a perfect crystal, and experimentally performed in 1974 by Rauch et al. The precise measurements with LLL neutron interferometers were performed on scattering length, gravitational effect, coherence, Fizeau effects, spin superposition, complementarity, and post-selection effects. Since the early stage of quantum physics, the double-slit experiment has served as the example of the epistemologically strange features of quantum phenomena, and its course of study is described. The time-delayed interferometry with nuclear resonant scattering of synchrotron radiation and phase transfer in time-delayed interferometry with nuclear resonant scattering were experimented, and are briefly reported. A geometric phase factor was derived for a split beam experiment as an example of cyclic evolution. The geometric phase was observed with a two-loop neutron interferometer. All the experimental results showed complete agreement with the theoretical treatment. (K.I.)

  2. Time-of-flight detection of ultra-cold atoms using resonant frequency modulation imaging.

    Science.gov (United States)

    Hardman, K S; Wigley, P B; Everitt, P J; Manju, P; Kuhn, C C N; Robins, N P

    2016-06-01

    Resonant frequency modulation imaging is used to detect free falling ultra-cold atoms. A theoretical comparison of fluorescence imaging (FI) and frequency modulation imaging (FMI) is made, indicating that for low optical depth clouds, FMI accomplished a higher signal-to-noise ratio under conditions necessary for a 200 μm spatially resolved atom interferometer. A 750 ms time-of-flight measurement reveals near atom shot-noise limited number measurements of 2×106 Bose-condensed Rb87 atoms. The detection system is applied to high precision spinor BEC based atom interferometer.

  3. Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)

    Science.gov (United States)

    Roberts, B.

    1986-01-01

    The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.

  4. Fourier Transform Fabry-Perot Interferometer

    Science.gov (United States)

    Snell, Hilary E.; Hays, Paul B.

    1992-01-01

    We are developing a compact, rugged, high-resolution remote sensing instrument with wide spectral scanning capabilities. This relatively new type of instrument, which we have chosen to call the Fourier-Transform Fabry-Perot Interferometer (FT-FPI), is accomplished by mechanically scanning the etalon plates of a Fabry-Perot interferometer (FPI) through a large optical distance while examining the concomitant signal with a Fourier-transform analysis technique similar to that employed by the Michelson interferometer. The FT-FPI will be used initially as a ground-based instrument to study near-infrared atmospheric absorption lines of trace gases using the techniques of solar absorption spectroscopy. Future plans include modifications to allow for measurements of trace gases in the stratosphere using spectral lines at terahertz frequencies.

  5. Two-wavelength HeNe laser interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Granneman, E.H.A.

    1981-03-24

    This paper presents an interferometer set-up in which two wavelengths are used simultaneously. This enables one to determine separately the phase shifts caused by changes in plasma density and by mechanical vibrations of the interferometer structure.

  6. Application of Thin ZnO ALD Layers in Fiber-Optic Fabry-Pérot Sensing Interferometers

    OpenAIRE

    Daria Majchrowicz; Marzena Hirsch; Paweł Wierzba; Michael Bechelany; Roman Viter; Małgorzata Jędrzejewska‑Szczerska

    2016-01-01

    In this paper we investigated the response of a fiber-optic Fabry-Pérot sensing interferometer with thin ZnO layers deposited on the end faces of the optical fibers forming the cavity. Standard telecommunication single-mode optical fiber (SMF-28) segments were used with the thin ZnO layers deposited by Atomic Layer Deposition (ALD). Measurements were performed with the interferometer illuminated by two broadband sources operating at 1300 nm and 1550 nm. Reflected interference signal was acqui...

  7. Digital holographic Michelson interferometer for nanometrology

    Science.gov (United States)

    Sevrygin, Alexander A.; Korotkov, V. I.; Pulkin, S. A.; Tursunov, I. M.; Venediktov, D. V.; Venediktov, V. Yu.; Volkov, O. V.

    2014-11-01

    The paper considers the dynamic holographic interferometry schemes with amplification (multiplication) of holographic fringes and with correction for distortions, imposed by the interferometer scheme elements. The use of digital microscope and of the matrix light modulator with direct addressing provides the completely digital closed-loop performance of the overall system for real-time evaluation of nano-scale objects size. Considered schemes were verified in the laboratory experiment, using the Michelson micro-interferometer, equipped by the USB-microscope and digital holography stage, equipped by the Holoeye spatial light modulator.

  8. Multiple reflection Michelson interferometer with picometer resolution.

    Science.gov (United States)

    Pisani, Marco

    2008-12-22

    A Michelson interferometer based on an optical set-up allowing multiple reflection between two plane mirrors performs the multiplication of the optical path by a factor N, proportionally increasing the resolution of the measurement. A multiplication factor of almost two orders of magnitude has been demonstrated with a simple set-up. The technique can be applied to any interferometric measurement where the classical interferometer limits due to fringe nonlinearities and quantum noise are an issue. Applications in precision engineering, vibration analysis, nanometrology, and spectroscopy are foreseen.

  9. Quantum Spin Transport in Mesoscopic Interferometer

    Directory of Open Access Journals (Sweden)

    Zein W. A.

    2007-10-01

    Full Text Available Spin-dependent conductance of ballistic mesoscopic interferometer is investigated. The quantum interferometer is in the form of ring, in which a quantum dot is embedded in one arm. This quantum dot is connected to one lead via tunnel barrier. Both Aharonov- Casher and Aharonov-Bohm e ects are studied. Our results confirm the interplay of spin-orbit coupling and quantum interference e ects in such confined quantum systems. This investigation is valuable for spintronics application, for example, quantum information processing.

  10. Continuous phase amplification with a Sagnac interferometer

    CERN Document Server

    Starling, David J; Williams, Nathan S; Jordan, Andrew N; Howell, John C

    2009-01-01

    We describe a weak value inspired phase amplification technique in a Sagnac interferometer. We monitor the relative phase between two paths of a slightly misaligned interferometer by measuring the average position of a split-Gaussian mode in the dark port. Although we monitor only the dark port, we show that the signal varies linearly with phase and that we can obtain similar sensitivity to balanced homodyne detection. We derive the source of the amplification both with classical wave optics and as an inverse weak value.

  11. Superconducting on-chip microwave interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, Edwin P.; Fischer, Michael; Schneider, Christian; Baust, Alexander; Eder, Peter; Goetz, Jan; Haeberlein, Max; Schwarz, Manuel; Wulschner, Karl Friedrich; Xie, Edwar; Zhong, Ling; Deppe, Frank; Fedorov, Kirill; Huebl, Hans; Marx, Achim; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany)

    2015-07-01

    In the realm of all-microwave quantum computation, information is encoded in itinerant microwave photons propagating along transmission lines. In such a system unitary operations are implemented by linear elements such as beam splitters or interferometers. However, for two-qubit operations non-linear gates, e.g., c-phase gates are required. In this work, we investigate superconducting interferometers as a building block of a c-phase gate. We experimentally characterize their scattering properties and compare them to simulation results. Finally, we discuss our progress towards the realization of a c-phase gate.

  12. A naturally stable Sagnac-Michelson nonlinear interferometer

    OpenAIRE

    Lukens, Joseph M.; Peters, Nicholas A.; Pooser, Raphael C.

    2016-01-01

    Interferometers measure a wide variety of dynamic processes by converting a phase change into an intensity change. Nonlinear interferometers, making use of nonlinear media in lieu of beamsplitters, promise substantial improvement in the quest to reach the ultimate sensitivity limits. Here we demonstrate a new nonlinear interferometer utilizing a single parametric amplifier for mode mixing---conceptually, a nonlinear version of the conventional Michelson interferometer with its arms collapsed ...

  13. Analysis of polarizability measurements made with atom interferometry

    CERN Document Server

    Gregoire, Maxwell D; Trubko, Raisa; Cronin, Alexander D

    2016-01-01

    We present revised measurements of the static electric dipole polarizabilities of K, Rb, and Cs based on atom interferometer experiments presented in [Phys. Rev. A 2015, 92, 052513] but now re-analyzed with new calibrations for the magnitude and geometry of the applied electric field gradient. The resulting polarizability values did not change, but the uncertainties were significantly reduced. Then we interpret several measurements of alkali metal atomic polarizabilities in terms of atomic oscillator strengths $f_{ik}$, Einstein coefficients $A_{ik}$, state lifetimes $\\tau_{k}$, transition dipole matrix elements $D_{ik}$, line strengths $S_{ik}$, and van der Waals $C_6$ coefficients. Finally, we combine atom interferometer measurements of polarizabilities with independent measurements of lifetimes and $C_6$ values in order to quantify the residual contribution to polarizability due to all atomic transitions other than the principal $ns$-$np_J$ transitions for alkali metal atoms.

  14. Analysis of Polarizability Measurements Made with Atom Interferometry

    Directory of Open Access Journals (Sweden)

    Maxwell D. Gregoire

    2016-07-01

    Full Text Available We present revised measurements of the static electric dipole polarizabilities of K, Rb, and Cs based on atom interferometer experiments presented in [Phys. Rev. A 2015, 92, 052513] but now re-analyzed with new calibrations for the magnitude and geometry of the applied electric field gradient. The resulting polarizability values did not change, but the uncertainties were significantly reduced. Then, we interpret several measurements of alkali metal atomic polarizabilities in terms of atomic oscillator strengths fik, Einstein coefficients Aik, state lifetimes τk, transition dipole matrix elements Dik, line strengths Sik, and van der Waals C6 coefficients. Finally, we combine atom interferometer measurements of polarizabilities with independent measurements of lifetimes and C6 values in order to quantify the residual contribution to polarizability due to all atomic transitions other than the principal ns-npJ transitions for alkali metal atoms.

  15. Smart photogalvanic running-grating interferometer

    DEFF Research Database (Denmark)

    Kukhtarev, N. V.; Kukhtareva, T.; Edwards, M. E.

    2005-01-01

    Photogalvanic effect produces actuation of periodic motion of macroscopic LiNbO3 crystal. This effect was applied to the development of an all-optical moving-grating interferometer usable for optical trapping and transport of algae chlorella microorganisms diluted in water with a concentration of...

  16. Absolute distance metrology for space interferometers

    NARCIS (Netherlands)

    Swinkels, B.L.; Latoui, A.; Bhattacharya, N.; Wielders, A.A.; Braat, J.J.M.

    2005-01-01

    Future space missions, among which the Darwin Space Interferometer, will consist of several free flying satellites. A complex metrology system is required to have all the components fly accurately in formation and have it operate as a single instrument. Our work focuses on a possible implementation

  17. Thermoluminescence spectra measured with a Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Haschberger, P. (Technische Univ. Muenchen (Germany). Lehrstuhl fuer Elektrische Messtechnik)

    1991-01-01

    A Michelson interferometer was redesigned to prove its capabilities in the measurement of short-lived, low-intensity thermoluminescence spectra. Interferograms are collected during heating up the thermoluminescent probe in a heater plate. A personal computer controls the data acquisition and processes the Fourier transform. As the results show, even a comparatively simple and limited setup leads to relevant and reproducible spectra. (author).

  18. Method and device for aligning and interferometer

    NARCIS (Netherlands)

    Somers, P.A.A.

    2005-01-01

    Method and device for the alignment of an interferometer arrangement, which comprises an object beam part (4), a beam splitting part (5) and a beam combination part (6). A detector unit (2) is arranged to detect an interference pattern for two beams that can be differentiated, via each of n optical

  19. The effect of rotations on Michelson interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Maraner, Paolo, E-mail: pmaraner@unibz.it

    2014-11-15

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations.

  20. FIRI-A far-infrared interferometer

    NARCIS (Netherlands)

    Helmich, Frank P.; Ivison, R. J.

    2009-01-01

    Half of the energy ever emitted by stars and accreting objects comes to us in the far-infrared (FIR) waveband and has yet to be properly explored. We propose a powerful Far-InfraRed Interferometer mission, FIRI, to carry out high-resolution imaging spectroscopy in the FIR. This key observational cap

  1. Berkeley heterodyne interferometer. [for IR stellar observations

    Science.gov (United States)

    Betz, A.

    1975-01-01

    A prototype heterodyne stellar interferometer has been built in order to demonstrate the feasibility of heterodyne techniques in measuring angular diameters of bright infrared stars. The first system tests were performed in December 1972. Attention is given to investigations concerning the possibility that optical air turbulence within the structure of the solar telescope employed can possibly destroy the phase coherence of the fringe signals.

  2. Accurate measurement of interferometer group delay using field-compensated scanning white light interferometer.

    Science.gov (United States)

    Wan, Xiaoke; Wang, Ji; Ge, Jian

    2010-10-10

    Interferometers are key elements in radial velocity (RV) experiments in astronomy observations, and accurate calibration of the group delay of an interferometer is required for high precision measurements. A novel field-compensated white light scanning Michelson interferometer is introduced as an interferometer calibration tool. The optical path difference (OPD) scanning was achieved by translating a compensation prism, such that even if the light source were in low spatial coherence, the interference stays spatially phase coherent over a large interferometer scanning range. In the wavelength region of 500-560 nm, a multimode fiber-coupled LED was used as the light source, and high optical efficiency was essential in elevating the signal-to-noise ratio of the interferogram signal. The achromatic OPD scanning required a one-time calibration, and two methods using dual-laser wavelength references and an iodine absorption spectrum reference were employed and cross-verified. In an experiment measuring the group delay of a fixed Michelson interferometer, Fourier analysis was employed to process the interferogram data. The group delay was determined at an accuracy of 1×10(-5), and the phase angle precision was typically 2.5×10(-6) over the wide wavelength region.

  3. What and how does a Michelson interferometer measure?

    CERN Document Server

    Demjanov, V V

    2010-01-01

    Michelson interferometer is very complicated and capricious instrument. Even more mysterious and difficult to understand the nature of electrodynamic phenomena in moving media, which was studied by rotating the interferometer with two orthogonal coherent beams. Its idea was proposed, as is known, by Maxwell. Undertaking in 1881 the implementation of this idea, Michelson (since then the interferometer bears his name) assumed that the interferometer can measure the shift of the interference fringe when you turn the interferometer in vacuum, in the absence of media in zones of propagation of rays. Not at once there have been comprehended (after 1881 the misunderstanding lasted almost 90 years) that the shift of interference fringe in the Michelson interferometer is absent in vacuum and arises only when light's carriers of the interferometer are formed by dielectric media with the refractive index (n) exceeding unity (n>1). Intricacies of the relations of optically transparent media with the structural elements o...

  4. The low coherence Fabry-Pérot interferometer with diamond and ZnO layers

    Science.gov (United States)

    Majchrowicz, D.; Den, W.; Hirsch, M.

    2016-09-01

    The authors present a fiber-optic Fabry-Pérot interferometer built with the application of diamond and zinc oxide (ZnO) thin layers. Thin ZnO films were deposited on the tip of a standard telecommunication single-mode optical fiber (SMF- 28) while the diamond layer was grown on the plate of silicon substrate. Investigated ZnO layers were fabricated by atomic layer deposition (ALD) and the diamond films were deposited using Microwave Plasma Enhanced Chemical Vapor Deposition (μPE CVD) system. Different thickness of layers was examined. The measurements were performed for the fiber-optic Fabry-Pérot interferometer working in the reflective mode. Spectra were registered for various thicknesses of ZnO layer and various length of the air cavity. As a light source, two superluminescent diodes (SLD) with central wavelength of 1300 nm and 1550 nm were used in measurement set-up.

  5. A hybrid two-component Bose–Einstein condensate interferometer for measuring magnetic field gradients

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Fei [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Ministry of Education, Wuhan University of Technology, Wuhan 430070 (China); Huang, Jiahao, E-mail: hjiahao@mail2.sysu.edu.cn [TianQin Research Center & School of Physics and Astronomy, Sun Yat-Sen University, SYSU Zhuhai Campus, Zhuhai 519082 (China); Liu, Quan [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Ministry of Education, Wuhan University of Technology, Wuhan 430070 (China)

    2017-03-03

    Highlights: • A scheme for detecting magnetic field gradients via a double-well two-component Bose–Einstein condensate interferometer. • The magnetic field gradient can be extracted by either the spin population or the external state. • Our proposal is potentially sensitive to weak magnetic field inhomogeneity due to its small sensor size. - Abstract: We have proposed a scheme to detect magnetic field gradients via an interferometer based on a double-well two-component Bose–Einstein condensate (BEC). Utilizing a sequence of quantum control operations on both external and internal degree of the BEC, one can extract the magnetic field gradients by measuring either the population in one component or the fidelity between the final external state and the initial ground state. Our scheme can be implemented by current experimental techniques of manipulating ultracold atoms.

  6. A Transportable Gravity Gradiometer Based on Atom Interferometry

    Science.gov (United States)

    Yu, Nan; Thompson, Robert J.; Kellogg, James R.; Aveline, David C.; Maleki, Lute; Kohel, James M.

    2010-01-01

    A transportable atom interferometer-based gravity gradiometer has been developed at JPL to carry out measurements of Earth's gravity field at ever finer spatial resolutions, and to facilitate high-resolution monitoring of temporal variations in the gravity field from ground- and flight-based platforms. Existing satellite-based gravity missions such as CHAMP and GRACE measure the gravity field via precise monitoring of the motion of the satellites; i.e. the satellites themselves function as test masses. JPL's quantum gravity gradiometer employs a quantum phase measurement technique, similar to that employed in atomic clocks, made possible by recent advances in laser cooling and manipulation of atoms. This measurement technique is based on atomwave interferometry, and individual laser-cooled atoms are used as drag-free test masses. The quantum gravity gradiometer employs two identical atom interferometers as precision accelerometers to measure the difference in gravitational acceleration between two points (Figure 1). By using the same lasers for the manipulation of atoms in both interferometers, the accelerometers have a common reference frame and non-inertial accelerations are effectively rejected as common mode noise in the differential measurement of the gravity gradient. As a result, the dual atom interferometer-based gravity gradiometer allows gravity measurements on a moving platform, while achieving the same long-term stability of the best atomic clocks. In the laboratory-based prototype (Figure 2), the cesium atoms used in each atom interferometer are initially collected and cooled in two separate magneto-optic traps (MOTs). Each MOT, consisting of three orthogonal pairs of counter-propagating laser beams centered on a quadrupole magnetic field, collects up to 10(exp 9) atoms. These atoms are then launched vertically as in an atom fountain by switching off the magnetic field and introducing a slight frequency shift between pairs of lasers to create a moving

  7. Atomic-position Localization Via Dual Measurement

    CERN Document Server

    Nha, H; Chang, J S; An, K; Nha, Hyunchul; Lee, Jai-Hyung; Chang, Joon-Sung; An, Kyungwon

    2002-01-01

    We study localization of atomic position when a three-level atom interacts with a quantized standing-wave field in the Ramsey interferometer setup. Both the field quadrature amplitude and the atomic internal state are measured to obtain the atomic position information. It is found that this dual measurement scheme produces an interference pattern superimposed on a diffraction-like pattern in the atomic position distribution, where the former pattern originates from the state-selective measurement and the latter from the field measurement. The present scheme results in a better resolution in the position localization than the field-alone measurement schemes. We also discuss the measurement-correlated mechanical action of the standing-wave field on the atom in the light of Popper's test.

  8. Phase locking a clock oscillator to a coherent atomic ensemble

    CERN Document Server

    Kohlhaas, R; Cantin, E; Aspect, A; Landragin, A; Bouyer, P

    2015-01-01

    The sensitivity of an atomic interferometer increases when the phase evolution of its quantum superposition state is measured over a longer interrogation interval. In practice, a limit is set by the measurement process, which returns not the phase, but its projection in terms of population difference on two energetic levels. The phase interval over which the relation can be inverted is thus limited to the interval $[-\\pi/2,\\pi/2]$; going beyond it introduces an ambiguity in the read out, hence a sensitivity loss. Here, we extend the unambiguous interval to probe the phase evolution of an atomic ensemble using coherence preserving measurements and phase corrections, and demonstrate the phase lock of the clock oscillator to an atomic superposition state. We propose a protocol based on the phase lock to improve atomic clocks under local oscillator noise, and foresee the application to other atomic interferometers such as inertial sensors.

  9. Michelson interferometer for precision angle measurement.

    Science.gov (United States)

    Ikram, M; Hussain, G

    1999-01-01

    An angle-measuring technique based on an optical interferometer is reported. The technique exploits a Michelson interferometric configuration in which a right-angle prism and a glass strip are introduced into a probe beam. Simultaneous rotation of both components along an axis results in an optical path difference between the reference and the probe beams. In a second arrangement two right-angle prisms and glass strips are introduced into two beams of a Michelson interferometer. The prisms and the strips are rotated simultaneously to introduce an optical path difference between the two beams. In our arrangement, optimization of various parameters makes the net optical path difference between the two beams approximately linear for a rotation as great as +/-20 degrees . Results are simulated that show an improvement of 2-3 orders of magnitude in error and nonlinearity compared with a previously reported technique.

  10. Adaptive DFT-based Interferometer Fringe Tracking

    Science.gov (United States)

    Wilson, Edward; Pedretti, Ettore; Bregman, Jesse; Mah, Robert W.; Traub, Wesley A.

    2004-01-01

    An automatic interferometer fringe tracking system has been developed, implemented, and tested at the Infrared Optical Telescope Array (IOTA) observatory at Mt. Hopkins, Arizona. The system can minimize the optical path differences (OPDs) for all three baselines of the Michelson stellar interferometer at IOTA. Based on sliding window discrete Fourier transform (DFT) calculations that were optimized for computational efficiency and robustness to atmospheric disturbances, the algorithm has also been tested extensively on off-line data. Implemented in ANSI C on the 266 MHz PowerPC processor running the VxWorks real-time operating system, the algorithm runs in approximately 2.0 milliseconds per scan (including all three interferograms), using the science camera and piezo scanners to measure and correct the OPDs. The adaptive DFT-based tracking algorithm should be applicable to other systems where there is a need to detect or track a signal with an approximately constant-frequency carrier pulse.

  11. Line-imaging Fabry-Perot interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, A.R.; Warnes, R.H.; Hemsing, W.F.; Whittemore, G.R.

    1990-01-01

    A method for measuring the velocity history of a line element on a shock-loaded solid has been demonstrated. Light from single-frequency laser is focused through a cylindrical lens to a line on a moving target. The return Doppler-shifted image is passed through a Fabry-Perot interferometer. Because only specific combinations of incident light angle and frequency can pass through the interferometer the output is an incomplete image of the moving target appearing as a set of fringes. This image is focused onto an electronic streak camera and swept in time. The fringe pattern changes with time as the target surface moves, allowing determination of velocity for each point on the target that forms a fringe. Because the velocity can only be measured at the fringe positions, it is necessary to use an interpolating polynomial to obtain a continuous function of time and velocity along the sampled lien. 9 refs., 7 figs.

  12. Interferometer for Low-Uncertainty Vector Metrology

    Science.gov (United States)

    Toland, Ronald W.; Leviton, Douglas B.

    2006-01-01

    A simplified schematic diagram of a tilt-sensing unequal-path interferometer set up to measure the orientation of the normal vector of one surface of a cube mounted on a structure under test is described herein. This interferometer has been named a "theoferometer" to express both its interferometric nature and the intention to use it instead of an autocollimating theodolite. The theoferometer optics are mounted on a plate, which is in turn mounted on orthogonal air bearings for near-360 rotation in azimuth and elevation. Rough alignment of the theoferometer to the test cube is done by hand, with fine position adjustment provided by a tangent arm drive using linear inchwormlike motors.

  13. The upgraded S18 neutron interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Bruckner, G. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)]|[Atominstitut der Oesterreichischen Universitaeten, Vienna (Austria)

    1999-11-01

    The instrument S18, the perfect-crystal neutron interferometer was reopened in October 1998. The instrument, which was dismantled during the reactor shutdown, has been set up again within the last two years. The upgraded version allows more advanced neutron optics experiments for fundamental, nuclear and condensed-matter physics. The instrument also takes advantage of the new super-mirror guide which provides considerably higher intensities. Several types of large perfect-crystal interferometers are available for different applications. A new multipurpose monochromator allows the use of a wide wavelength range and the configuration of the system as an advanced high-resolution Bonse-Hart small-angle scattering camera. Another instrument option is the use of completely polarised beams which are obtained using permanent magnetic prism deflection. An additional third analyser axis permits novel post-selection experiments concerning momentum distribution and polarisation analysis of the interfering beams. (author) 11 refs., 2 figs.

  14. Thermal-noise-limited underground interferometer CLIO

    CERN Document Server

    Agatsuma, Kazuhiro; Fujimoto, Masa-Katsu; Kawamura, Seiji; Kuroda, Kazuaki; Miyakawa, Osamu; Miyoki, Shinji; Ohashi, Masatake; Suzuki, Toshikazu; Takahashi, Ryutaro; Tatsumi, Daisuke; Telada, Souichi; Uchiyama, Takashi; Yamamoto, Kazuhiro

    2009-01-01

    We report on the current status of CLIO (Cryogenic Laser Interferometer Observatory), which is a prototype interferometer for LCGT (Large scale Cryogenic Gravitational-wave Telescope). LCGT is a Japanese next-generation interferometric gravitational wave detector featuring the use of cryogenic mirrors and a quiet underground site. The main purpose of CLIO is to demonstrate a reduction of the mirror thermal noise by cooling the sapphire mirrors. CLIO is located in an underground site of the Kamioka mine, 1000 m deep from the mountain top, to verify its advantages. After a few years of commissioning work, we have achieved a thermal-noise-limited sensitivity at room temperature. One of the main results of noise hunting was the elimination of thermal noise caused by a conductive coil-holder coupled with a pendulum through magnets.

  15. Future Gravitational Wave Detectors Based on Atom Interferometry

    CERN Document Server

    Geiger, Remi

    2016-01-01

    We present the perspective of using atom interferometry for gravitational wave (GW) detection in the mHz to about 10 Hz frequency band. We focus on light-pulse atom interferometers which have been subject to intense developments in the last 25 years. We calculate the effect of the GW on the atom interferometer and present in details the atomic gradiometer configuration which has retained more attention recently. The principle of such a detector is to use free falling atoms to measure the phase of a laser, which is modified by the GW. We highlight the potential benefits of using atom interferometry compared to optical interferometry as well as the challenges which remain for the realization of an atom interferometry based GW detector. We present some of the important noise sources which are expected in such detectors and strategies to cirucumvent them. Experimental techniques related to cold atom interferometers are briefly explained. We finally present the current progress and projects in this rapidly evolvin...

  16. Temperature insensitive fiber optic interferometer and applications

    OpenAIRE

    Murphy, Kent A.

    1989-01-01

    A method of modifying a uÌ ber optic fused biconical tapered coupler to produce a relatively temperature insensitive Michelson interferometer is presented. The modification was accomplished by cleaving the coupler after the minimum taper region and polishing, perpendicular to the endface, to a point just short of the interaction region. This allows one of the two fiber cores, which are within micrometers of each other with their claddings fused together, to be coated at its end...

  17. First Colombian Solar Radio Interferometer: current stage

    Science.gov (United States)

    Guevara Gómez, J. C.; Martínez Oliveros, J. C.; Calvo-Mozo, B.

    2017-10-01

    Solar radio astronomy is a fast developing research field in Colombia. Here, we present the scientific goals, specifications and current state of the First Colombian Solar Radio Interferometer consisting of two log-periodic antennas covering a frequency bandwidth op to 800 MHz. We describe the importance and benefits of its development to the radioastronomy in Latin America and its impact on the scientific community and general public.

  18. Photonic Crystal Fiber Interferometer for Dew Detection

    OpenAIRE

    Mathew, Jinesh; Semenova, Yuliya; Farrell, Gerald

    2012-01-01

    A novel method for dew detection based on photonic crystal fiber (PCF) interferometer that operates in reflection mode is presented in this paper. The fabrication of the sensor head is simple since it only involves cleaving and fusion splicing. The sensor shows good sensitivity to dew formation with a large wavelength peak shift of the interference pattern at the onset of dew formation. The device’s response to ambient humidity and temperature are also studied and reported in this paper. From...

  19. Measurement of small vibration by laser interferometer

    Institute of Scientific and Technical Information of China (English)

    QIAN Menglu; LIU Hewei

    2003-01-01

    The method and experimental results of measuring a small vibrating displacement by laser interferometer are introduced in this paper. The dynamic response of a new kind of tiny piezoelectric driver is detected. Results show that this kind of PZN-PZT tiny driver not only has high voltage-displacement sensitivity, but also its frequency response approaches to 1 kHz.Therefore this kind of piezoelectric driver can be used widely in many fields.

  20. Hybrid photonic chip interferometer for embedded metrology

    Science.gov (United States)

    Kumar, P.; Martin, H.; Maxwell, G.; Jiang, X.

    2014-03-01

    Embedded metrology is the provision of metrology on the manufacturing platform, enabling measurement without the removal of the work piece. Providing closer integration of metrology upon the manufacturing platform can lead to the better control and increased throughput. In this work we present the development of a high precision hybrid optical chip interferometer metrology device. The complete metrology sensor system is structured into two parts; optical chip and optical probe. The hybrid optical chip interferometer is based on a silica-on-silicon etched integrated-optic motherboard containing waveguide structures and evanescent couplers. Upon the motherboard, electro-optic components such as photodiodes and a semiconductor gain block are mounted and bonded to provide the required functionality. The key structure in the device is a tunable laser module based upon an external-cavity diode laser (ECDL). Within the cavity is a multi-layer thin film filter which is rotated to select the longitudinal mode at which the laser operates. An optical probe, which uses a blazed diffracting grating and collimating objective lens, focuses light of different wavelengths laterally over the measurand. Incident laser light is then tuned in wavelength time to effectively sweep an `optical stylus' over the surface. Wavelength scanning and rapid phase shifting can then retrieve the path length change and thus the surface height. We give an overview of the overall design of the final hybrid photonic chip interferometer, constituent components, device integration and packaging as well as experimental test results from the current version now under evaluation.

  1. Coherence and information in a fiber interferometer

    CERN Document Server

    Kellerer, Aglaé; Lacour, Sylvestre

    2016-01-01

    We present an experiment based on a fibered Mach-Zehnder interferometer. The aim is to familiarize students with fibered optics and interferometry, and to improve their understanding of optical amplification. The laboratory project has two parts: in a first part, the students modulate the optical path of the interferometer to study the spectra of light sources via Fourier Transform Spectroscopy. In a second part, an optical amplifier is placed in one or both arms of the interferometer. The set-up uses monomode, polarization-maintaining fibers that propagate light of 1.5 $\\mu$m wavelength. In this article, we describe the set-up and the analysis of the measurements, and we present results from student reports. All components are part of standard optical catalogues. Even though the experiment is based on fibered optics, it is robust to manipulation (it is however relatively expensive $\\sim \\pounds 15\\,000$): We describe our efforts to protect the components from damage. This experiment is now offered as a 2-wee...

  2. Model-based phase-shifting interferometer

    Science.gov (United States)

    Liu, Dong; Zhang, Lei; Shi, Tu; Yang, Yongying; Chong, Shiyao; Miao, Liang; Huang, Wei; Shen, Yibing; Bai, Jian

    2015-10-01

    A model-based phase-shifting interferometer (MPI) is developed, in which a novel calculation technique is proposed instead of the traditional complicated system structure, to achieve versatile, high precision and quantitative surface tests. In the MPI, the partial null lens (PNL) is employed to implement the non-null test. With some alternative PNLs, similar as the transmission spheres in ZYGO interferometers, the MPI provides a flexible test for general spherical and aspherical surfaces. Based on modern computer modeling technique, a reverse iterative optimizing construction (ROR) method is employed for the retrace error correction of non-null test, as well as figure error reconstruction. A self-compiled ray-tracing program is set up for the accurate system modeling and reverse ray tracing. The surface figure error then can be easily extracted from the wavefront data in forms of Zernike polynomials by the ROR method. Experiments of the spherical and aspherical tests are presented to validate the flexibility and accuracy. The test results are compared with those of Zygo interferometer (null tests), which demonstrates the high accuracy of the MPI. With such accuracy and flexibility, the MPI would possess large potential in modern optical shop testing.

  3. Manipulation of quantum states in a memory cell: controllable Mach-Zehnder interferometer

    Science.gov (United States)

    Losev, A. S.; Golubeva, T. Yu; Golubev, Yu M.

    2017-05-01

    In this article, we consider the possibility of manipulation of quantum signals, ensured by the use of the tripod-type atomic memory cell. We show that depending on a configuration of driving fields at the writing and reading, such a cell allows the signal to both be stored and transformed. It is possible to provide the operation of the memory cell in a Mach-Zehnder interferometer mode passing two successive pulses at the input. We proposed a procedure of partial signal readout that provides entanglement between the retrieved light and the atomic ensemble. Thus, we have shown that a tripod atomic cell is a promising candidate to implement quantum logical operations, including two-qubit ones, which can be performed on the basis of only one cell.

  4. Observing the average momentum flow lines of particles in a double slit interferometer

    Science.gov (United States)

    Morley, Joel; Edmunds, Peter; Barker, Peter; Hiley, Basil; Flack, Rob; Monachello, Vincenzo; Experimental Weak Values Team

    2016-05-01

    The 1988 work on weak values by Aharonov et al., introduced a new kind of quantum variable. This created new perspectives when it came to the limits of quantum uncertainty. More recently, Kocsis et al. had used these techniques experimentally, claiming to have reconstructed the trajectories of photons after passing through an interferometer. This was done without destroying the interference pattern, an act apparently forbidden by standard quantum mechanics. We aim to replicate Kocsis' experiment using atoms. A ready made magneto-optical trap can routinely cool and trap, metastable argon atoms to the mK range. The ultra-cold temperatures offers particles with a large De Broglie wavelength. Here we present our intended method of reconstructing the atom's trajectories, while maintaining the interference pattern, as they fall below the slits. Thanks to the John E. Fetzer Memorial Fund.

  5. Atom chip gravimeter

    Science.gov (United States)

    Schubert, Christian; Abend, Sven; Gebbe, Martina; Gersemann, Matthias; Ahlers, Holger; Müntinga, Hauke; Matthias, Jonas; Sahelgozin, Maral; Herr, Waldemar; Lämmerzahl, Claus; Ertmer, Wolfgang; Rasel, Ernst

    2016-04-01

    1552-1557 (QUANTUS-IV-Fallturm) and by the Deutsche Forschungsgemeinschaft in the framework of the SFB 1128 geo-Q. [1] P. Berg et al., Composite-Light-Pulse Technique for High-Precision Atom Interferometry, Phys. Rev. Lett., 114, 063002, 2015. [2] A. Peters et al., Measurement of gravitational acceleration by dropping atoms, Nature 400, 849, 1999. [3] D. Schlippert et al., Quantum Test of the Universality of Free Fall, Phys. Rev. Lett., 112, 203002, 2014. [4] A. Louchet-Chauvet et al., The influence of transverse motion within an atomic gravimeter, New J. Phys. 13, 065026, 2011. [5] Q. Bodart et al., A cold atom pyramidal gravimeter with a single laser beam, Appl. Phys. Lett. 96, 134101, 2010. [6] H. Müntinga et al., Interferometry with Bose-Einstein Condensates in Microgravity, Phys. Rev. Lett., 110, 093602, 2013. [7] T. Kovachy et al., Matter Wave Lensing to Picokelvin Temperatures, Phys. Rev. Lett. 114, 143004, 2015. [8] J. Rudolph et al., A high-flux BEC source for mobile atom interferometers, New J. Phys. 17, 065001, 2015.

  6. Differential phase extraction in an atom gradiometer

    CERN Document Server

    Santos, Franck Pereira dos

    2015-01-01

    We present here a method for the extraction of the differential phase of an atom gradiometer that exploits the correlation of the vibration signal measured by an auxiliary classical sensor, such as a seismometer or an accelerometer. We show that sensitivities close to the quantum projection noise limit can be reached, even when the vibration noise induces phase fluctuations larger than 2$\\pi$. This method doesn't require the correlation between the atomic and classical signals to be perfect and allows for an exact determination of the differential phase, with no bias. It can also be applied to other configurations of differential interferometers, such as for instance gyrometers, conjugate interferometers for the measurement of the fine structure constant, or differential accelerometers for tests of the equivalence principle or detection of gravitational waves.

  7. Refractometric sensor based on all-fiber coaxial Michelson interferometers

    Science.gov (United States)

    Barrios, Paola; Sáez-Rodríguez, David; Rodríguez, Amparo; Cruz, José L.; Díez, Antonio; Andrés, Miguel V.

    2009-05-01

    All-fiber coaxial Michelson interferometers are compact and very stable interferometers that can be dipped directly into water solutions for chemical and biological sensing. The sensitivity of the cladding mode to the surrounding medium can be exploited to use the interferometer as a compact fiber refractometer. Several interferometers have been fabricated and characterized as glucose sensors. A first series of devices were designed to work at 1550 nm, while a second series was prepared to work at 850 nm. Thus, the second series of interferometers enables the use of compact, robust and low cost optical spectrum analyzers. In our present experiments, the length of the fiber that forms the interferometer was within the range 1-10 cm. When the shift of the spectrum maxima were measured as a function of the glucose concentration, a slope of 350 pm/% was achieved. The use of the 850 nm sensor heads as a portable sensor system to monitor sewage treatment plants is shown.

  8. A Michelson-type Radio Interferometer for University Education

    CERN Document Server

    Koda, Jin; Hasegawa, Tetsuo; Hayashi, Masahiko; Shafto, Gene; Slechta, Jeff; Metchev, Stanimir

    2016-01-01

    We report development of a simple and affordable radio interferometer suitable as an educational laboratory experiment. With the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the future generation of astronomers. This interferometer provides the hands-on experience needed to fully understand the basic concepts of interferometry. The design of this interferometer is based on the Michelson & Pease stellar optical interferometer, but operates at a radio wavelength (~11 GHz; ~2.7cm); thus the requirement for optical accuracy is much less stringent. We utilize a commercial broadcast satellite dish and feedhorn. Two flat side mirrors slide on a ladder, providing baseline coverage. This interferometer resolves and measures the diameter of the Sun, a nice daytime experiment which can be carried out even in marginal weather (i.e., partial cloud cover). Commercial broadcast satellites provide convenient point sources for comparison to the Su...

  9. Two-interferometer fiber optic sensor with disturbance localization

    Science.gov (United States)

    Kondrat, M.; Szustakowski, M.; Ciurapinski, W.; Zyczkowski, M.

    2006-09-01

    We present investigation results of a new generation of the fiber optic perimeter sensor in a Sagnac and Michelson interferometers configuration. This sensor can detect a potential intruder and determine its position along a protected zone. We propose a localization method that makes use of the inherent properties of both interferometers. After demodulation of signals from both interferometers, the obtained amplitude characteristic of the Sagnac interferometer depends on position of a disturbance along the interferometer, while amplitude characteristic of the Michelson interferometer do not depend on this position. So, quotient of both demodulated characteristics makes it possible to localize the disturbance. Arrangement of a laboratory model of the sensor and its signal processing scheme is also presented. During research of the laboratory model of the sensor, it was possible to detect the position of the disturbance with resolution of about 40m along the 6-km long sensor.

  10. Development of stable monolithic wide-field Michelson interferometers

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-01

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10-6/° C near 550nm, which corresponds to ˜800m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations.

  11. Development of stable monolithic wide-field Michelson interferometers.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-20

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations.

  12. Special topics in infrared interferometry. [Michelson interferometer development

    Science.gov (United States)

    Hanel, R. A.

    1985-01-01

    Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented.

  13. Modelling of interference pattern produced by Michelson interferometer

    Science.gov (United States)

    Glebov, Victor; Lashmanov, Oleg

    2016-04-01

    Using of Michelson interferometer is shown in the field of measurement of periodical displacements of the con-trolled object. The foundations of optical interferometry are presented. The features of Michelson interferometer are described. The mathematical model of interference pattern produced by Michelson interferometer is created. It takes in consideration such parameters as the angles at which the mirrors are located and the lengths of two optical paths.

  14. Analysis of a four-mirror-cavity enhanced Michelson interferometer.

    Science.gov (United States)

    Thüring, André; Lück, Harald; Danzmann, Karsten

    2005-12-01

    We investigate the shot-noise-limited sensitivity of a four-mirror-cavity enhanced Michelson interferometer. The intention of this interferometer topology is the reduction of thermal lensing and the impact of the interferometers contrast although transmissive optics are used with high circulating powers. The analytical expressions describing the light fields and the frequency response are derived. Although the parameter space has 11 dimensions, a detailed analysis of the resonance feature gives boundary conditions allowing systematic parameter studies.

  15. Heterodyne Interferometer for Triggering Gas-Puff PRSs

    Science.gov (United States)

    2007-11-02

    completion of the Phase I effort. They are: "* Implement a heterodyne interferometer in a Michelson format using fiber optic components. "* Interface the...of single-mode fiber cable. These fibers represent the two legs of a Michelson interferometer . One fiber is terminated in a reflector and is the...independently through the same fiber to the interferometer head. They are subject to identical stresses and, therefore, incur identical phase noise which cancels

  16. HCN Laser Interferometer on the EAST Superconducting Tokamak

    Institute of Scientific and Technical Information of China (English)

    XU Qiang; GAO Xiang; JIE Yinxian; LIU Haiqing; SHI Nan; CHENG Yongfei; TONG Xingde

    2008-01-01

    A single-channel far-infrared (FIR) laser interferometer was developed to measure the line averaged electron density on the EAST tokamak. The structure of the single-channel FIR laser interferometer is described in detail. The evolution of density sawtooth oscillation was measured by means the FIR laser interferometer, and was identified by electron cyclotron emission (ECE) signals and soft X-ray intensity. The discharges with and without sawtooth were compared with each other in the Hugill diagram.

  17. Terrestrial Planet Finder Interferometer: Architecture, Mission Design, and Technology Development

    Science.gov (United States)

    Henry, Curt

    2004-01-01

    This slide presentation represents an overview progress report about the system design and technology development of two interferometer concepts studied for the Terrestrial Planet Finder (TPF) project. The two concepts are a structurally-connected interferometer (SCI) intended to fulfill minimum TPF science goals and a formation-flying interferometer (FFI) intended to fulfill full science goals. Described are major trades, analyses, and technology experiments completed. Near term plans are also described. This paper covers progress since August 2003

  18. Analysis of a four-mirror-cavity enhanced Michelson interferometer

    OpenAIRE

    Thüring, A.; Lück, H.; Danzmann, K.

    2005-01-01

    We investigate the shot noise limited sensitivity of a four-mirror cavity enhanced Michelson interferometer. The intention of this interferometer topology is the reduction of thermal lensing and the impact of the interferometers contrast although transmissive optics are used with high circulating powers. The analytical expressions describing the light fields and the frequency response are derived. Although the parameter space has 11 dimensions, a detailed analysis of the resonance feature giv...

  19. Ultrashort-pulse lasers based on the Sagnac interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Bezrodnyi, V.I.; Prokhorenko, V.I.; Tikhonov, E.A.; Shpak, M.T.; Iatskiv, D.IA.

    1988-01-01

    Results of experimental studies carried out on passively mode-locked and synchronously pumped ultrashort-pulse lasers with cavities based on the Sagnac interferometer are reported. It is shown that the use of the interferometer makes it possible to substantially improve the principal parameters of the ultrashort-pulse laser, such as repeatability, stability, spatial-angular characteristics, and the frequency tuning range. In particular, results are presented for YAG:Nd(3+) and dye lasers with Sagnac interferometers. 10 references.

  20. Observation of Atom-Wave Beats Using a Kerr Modulator for Atom Waves.

    Science.gov (United States)

    Décamps, B; Gillot, J; Vigué, J; Gauguet, A; Büchner, M

    2016-02-01

    A phase modulation puts the atom in a coherent superposition of quantum states with different kinetic energies. We have detected the interference of such modulated waves at the output of our atom interferometer, and we have observed beats at the difference of the modulation frequencies and its harmonics, in good agreement with theory. The phase modulations were produced by a Kerr phase modulator, i.e., by the propagation of the atom wave in a time-dependent electric field. An extension of this technique to electron interferometry should open the way to very high temporal resolution in electron microscopy.

  1. Tunable diode laser control by a stepping Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Valentin, A.; Nicolas, C.; Henry, L.; Mantz, A.W.

    1987-01-01

    A tunable diode laser beam is sent through a Michelson interferometer and is locked to a fringe of the diode laser interferometer pattern by controlling the diode laser polarization current. The path difference change of the Michelson interferometer is controlled step by step by a stabilized He--Ne red laser. When the interferometer path differences increases or decreases, the polarization current of the diode is forced to change in order to preserve the interference order of the diode beam. At every step the diode frequency is accurately fixed and its phase noise significantly reduced.

  2. Quantum heat engines based on electronic Mach-Zehnder interferometers

    Science.gov (United States)

    Hofer, Patrick P.; Sothmann, Björn

    2015-05-01

    We theoretically investigate the thermoelectric properties of heat engines based on Mach-Zehnder interferometers. The energy dependence of the transmission amplitudes in such setups arises from a difference in the interferometer arm lengths. Any thermoelectric response is thus of purely quantum-mechanical origin. In addition to an experimentally established three-terminal setup, we also consider a two-terminal geometry as well as a four-terminal setup consisting of two interferometers. We find that Mach-Zehnder interferometers can be used as powerful and efficient heat engines which perform well under realistic conditions.

  3. Two-path plasmonic interferometer with integrated detector

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, Gregory Conrad; Shaner, Eric A.; Aizin, Gregory

    2016-03-29

    An electrically tunable terahertz two-path plasmonic interferometer with an integrated detection element can down convert a terahertz field to a rectified DC signal. The integrated detector utilizes a resonant plasmonic homodyne mixing mechanism that measures the component of the plasma waves in-phase with an excitation field that functions as the local oscillator in the mixer. The plasmonic interferometer comprises two independently tuned electrical paths. The plasmonic interferometer enables a spectrometer-on-a-chip where the tuning of electrical path length plays an analogous role to that of physical path length in macroscopic Fourier transform interferometers.

  4. SHIMS -- A Spatial Heterodyne Interferometer for Methane Sounding Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project develops the Spatial Heterodyne Interferometer for Methane Sounding (SHIMS), a lightweight, compact, robust spectrometer system for remote sensing of...

  5. Electromagnetically induced transparency-based gas detector design using Michelson interferometer

    Science.gov (United States)

    Abbasian, Karim; Abdollahi, Mohammad Hossein

    2013-05-01

    In this paper, we have designed an all-optical controllable gas detector by doping 3-level Λ type nanocrystals in the moving arms' mirror of Michelson interferometer and used electromagnetically induced transparency (EIT) phenomenon to change its refractive index. By this means, we have created a controllable phase difference between light beams in two arms of the Michelson interferometer, where reflection phase of the EIT-based mirror changes about π radiant. Also, the signal reflection from EIT-based mirror changes between 0% and 100% approximately, while the second arm's signal is reflected completely. This EIT-based mirror's refractive index change can be a good alternative for conventional Michelson interferometer-based gas detector with one mechanical moving arm mirror (Undergraduate Instrumental Analysis, 6th edn. Marcel Dekker, New York, 2005), where long response time and unfix moving speed were its main drawbacks. While, in this scheme, not only these disadvantages are removed but also the response time can reach the electron transient time between the atomic energy levels. Then, by this all-optical tunable gas detector, we have achieved many modifications such as response time in sub-nanoseconds, high resolution, and high accuracy, or less cross sensitivity to other gas species.

  6. A hybrid two-component Bose-Einstein condensate interferometer for measuring magnetic field gradients

    Science.gov (United States)

    Xu, Fei; Huang, Jiahao; Liu, Quan

    2017-03-01

    We have proposed a scheme to detect magnetic field gradients via an interferometer based on a double-well two-component Bose-Einstein condensate (BEC). Utilizing a sequence of quantum control operations on both external and internal degree of the BEC, one can extract the magnetic field gradients by measuring either the population in one component or the fidelity between the final external state and the initial ground state. Our scheme can be implemented by current experimental techniques of manipulating ultracold atoms.

  7. The matter-wave laser interferometer gravitation antenna (MIGA: New perspectives for fundamental physics and geosciences

    Directory of Open Access Journals (Sweden)

    Canuel B.

    2014-01-01

    Full Text Available We are building a hybrid detector of new concept that couples laser and matter-wave interferometry to study sub Hertz variations of the strain tensor of space-time and gravitation. Using a set of atomic interferometers simultaneously manipulated by the resonant optical field of a 200 m cavity, the MIGA instrument will allow the monitoring of the evolution of the gravitational field at unprecedented sensitivity, which will be exploited both for geophysical studies and for Gravitational Waves (GWs detection. This new infrastructure will be embedded into the LSBB underground laboratory, ideally located away from major anthropogenic disturbances and benefitting from very low background noise.

  8. Laser-Free Cold-Atom Gymnastics

    Science.gov (United States)

    Gould, Harvey; Feinberg, Benedict; Munger, Charles T., Jr.; Nishimura, Hiroshi

    2017-01-01

    We have performed beam transport simulations on ultra cold (2 μK) and cold (130 μK) neutral Cs atoms in the F = M = + 4 (magnetic weak-field seeking) ground state. We use inhomogeneous magnetic fields to focus and accelerate the atoms. Acceleration of neutral atoms by an inhomogeneous magnetic field was demonstrated by Stern and Gerlach in 1922. In the simulations, a two mm diameter cloud of atoms is released to fall under gravity. A magnetic coil focuses the falling atoms. After falling 41 cm, the atoms are reflected in the magnetic fringe field of a solenoid. They return to their starting height, about 0.7 s later, having passed a second time through the focusing coil. The simulations show that > 98 % of ultra cold Cs atoms and > 70 % of cold Cs atoms will survive at least 15 round trips (assuming perfect vacuum). More than 100 simulations were run to optimize coil currents and focusing coil diameter and height. Simulations also show that atoms can be launched into a fountain. An experimental apparatus to test the simulations, is being constructed. This technique may find application in atomic fountain clocks, interferometers, and gravitometers, and may be adaptable for use in microgravity. It may also work with Bose-Einstein condensates of paramagnetic atoms.

  9. AGILIS: Agile Guided Interferometer for Longbaseline Imaging Synthesis. Demonstration and concepts of reconfigurable optical imaging interferometers

    Science.gov (United States)

    Woillez, Julien; Lai, Olivier; Perrin, Guy; Reynaud, François; Baril, Marc; Dong, Yue; Fédou, Pierre

    2017-06-01

    Context. In comparison to the radio and sub-millimetric domains, imaging with optical interferometry is still in its infancy. Due to the limited number of telescopes in existing arrays, image generation is a demanding process that relies on time-consuming reconfiguration of the interferometer array and super-synthesis. Aims: Using single mode optical fibres for the coherent transport of light from the collecting telescopes to the focal plane, a new generation of interferometers optimized for imaging can be designed. Methods: To support this claim, we report on the successful completion of the `OHANA Iki project: an end-to-end, on-sky demonstration of a two-telescope interferometer, built around near-infrared single mode fibres, carried out as part of the `OHANA project. Results: Having demonstrated that coherent transport by single-mode fibres is feasible, we explore the concepts, performances, and limitations of a new imaging facility with single mode fibres at its heart: Agile Guided Interferometer for Longbaseline Imaging Synthesis (AGILIS). Conclusions: AGILIS has the potential of becoming a next generation facility or a precursor to a much larger project like the Planet Formation Imager (PFI).

  10. Overcoming loss of contrast in atom interferometry due to gravity gradients

    CERN Document Server

    Roura, Albert; Schleich, Wolfgang P

    2014-01-01

    Long-time atom interferometry is instrumental to various high-precision measurements of fundamental physical properties, including tests of the equivalence principle. Due to rotations and gravity gradients, the classical trajectories characterizing the motion of the wave packets for the two branches of the interferometer do not close in phase space, an effect which increases significantly with the interferometer time. The relative displacement between the interfering wave packets in such open interferometers leads to a fringe pattern in the density profile at each exit port and a loss of contrast in the oscillations of the integrated particle number as a function of the phase shift. Paying particular attention to gravity gradients, we present a simple mitigation strategy involving small changes in the timing of the laser pulses which is very easy to implement. A useful representation-free description of the state evolution in an atom interferometer is introduced and employed to analyze the loss of contrast an...

  11. Representation-free description of light-pulse atom interferometry including non-inertial effects

    CERN Document Server

    Kleinert, Stephan; Roura, Albert; Schleich, Wolfgang P

    2015-01-01

    Light-pulse atom interferometers rely on the wave nature of matter and its manipulation with coherent laser pulses. They are used for precise gravimetry and inertial sensing as well as for accurate measurements of fundamental constants. Reaching higher precision requires longer interferometer times which are naturally encountered in microgravity environments such as drop-tower facilities, sounding rockets and dedicated satellite missions aiming at fundamental quantum physics in space. In all those cases, it is necessary to consider arbitrary trajectories and varying orientations of the interferometer set-up in non-inertial frames of reference. Here we provide a versatile representation-free description of atom interferometry entirely based on operator algebra to address this general situation. We show how to analytically determine the phase shift as well as the visibility of interferometers with an arbitrary number of pulses including the effects of local gravitational accelerations, gravity gradients, the ro...

  12. Three Cavity Tunable MEMS Fabry Perot Interferometer

    Directory of Open Access Journals (Sweden)

    Narayanswamy Sivakumar

    2007-12-01

    Full Text Available In this paper a four-mirror tunable micro electro-mechanical systems (MEMSFabry Perot Interferometer (FPI concept is proposed with the mathematical model. Thespectral range of the proposed FPI lies in the infrared spectrum ranging from 2400 to 4018(nm. FPI can be finely tuned by deflecting the two middle mirrors (or by changing the threecavity lengths. Two different cases were separately considered for the tuning. In case one,tuning was achieved by deflecting mirror 2 only and in case two, both mirrors 2 and 3 weredeflected for the tuning of the FPI.

  13. Sagnac interferometer for photothermal deflection spectroscopy.

    Science.gov (United States)

    Shiokawa, Naoyuki; Mizuno, Yuki; Tsuchiya, Harumasa; Tokunaga, Eiji

    2012-07-01

    Photothermal deflection spectroscopy is combined with a Sagnac interferometer to enhance the sensitivity of the absorption measurement by converting the photothermal beam deflection effect into the light intensity change by the interference effect. Because of stable light interference due to the common path, the signal intensity can be amplified without increasing the noise by extending the optical path length between a sample and a photodetector. The sensitivity is further improved by the use of focusing optics and double-pass geometry. This makes photothermal deflection spectroscopy applicable to any kind of material in the whole visible region with a xenon lamp for excitation and water or air as a deflection medium.

  14. Automatic alignment of a Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Barone, F.; Di Fiore, L.; Milano, L.; Russo, G.; Solimeno, S. (Inst. Nazionale di Fisica Nucleare, Napoli (IT))

    1992-04-01

    This paper describes the control system for the automatic control of a very large dual-wave Michelson interferometer to be used in the VIRGO experiment, a gravitational wave search in the band 10 to 3000 Hz. The system is mainly based on a VME bus architecture for the local controls, on which numeric control system based on digital filters are implemented. The authors describe these control systems, and the way they are linked together to form the global control system, in a hierarchical configuration.

  15. In-fiber Michelson interferometer inclinometer

    Science.gov (United States)

    da Silveira, C. R.; Jorge, P. A. S.; Costa, J. W. A.; Giraldi, M. T. M. R.; Santos, J. L.; Frazão, O.

    2015-09-01

    This work describes an in-fiber Michelson interferometer inclinometer which is sensitive to curvature applied in the tapered region. The performance of this inclinometer is evaluated by calculating the variation of the fringe visibility near the 1550 nm spectral range as a function of the tilt angle. It is presented the results of four experimental measurements and calculated the average and standard deviation of those measurements. The results indicate a good response of the sensor within the angular range between 3° and 6°. The average of those four measurements is around -0.15/° and the greatest standard deviation is about 5.5%.

  16. Interferometer -based Technology for Optical Nanoscale Inspection

    Directory of Open Access Journals (Sweden)

    Ryabko M.

    2014-02-01

    Full Text Available We demonstrate the interferometer-based approach for nanoscale grating Critical Dimension (CD measurements and prove the possibility to achieve no worse than 10 nm accuracy of measurements for 100 nm pitch gratings. The approach is based on phase shift measurement of light fields specularly reflected from periodical pattern and adjacent substrate with subsequent comparison between experimental and simulation results. RCWA algorithm is used to fit the measured results and extract the CD value. It is shown that accuracy of CD value measurement depends rather on the grating’s CD/pitch ratio than its CD value

  17. Data Flow System for the VLT Interferometer

    Science.gov (United States)

    Ballester, P.; Licha, T.; Percheron, I.; Sabet, C.

    2006-07-01

    A milestone on the accuracy of angular measurements is reached with each new instrument on the VLT interferometer: about 10 milliarcsec for MIDI (N Band), 1 milliarcsec for AMBER (JHK bands) and, later, the ultimate goal of 10 microarcsec for the PRIMA imaging and astrometry facility. Extracting the science information from these measurements requires a unified understanding of the data obtained by modelling, homogeneous calibration of large datasets and robust data reduction methods. We describe in this poster the operational tools provided for observation preparation, pipeline processing, and data quality control.

  18. Using ACT arrays as Intensity Interferometers

    CERN Document Server

    Le Bohec, S

    2005-01-01

    The Narrabri intensity interferometer was successfully used until 1974 to observe 32 stars, all brighter than B=+2.5, among which some were found to have an angular diameter as small as 0.41+/-0.03 milli-arc-seconds (mas). The technique was then abandoned in favor of Michelson interferometry. Here we consider the technical feasibility and scientific potential of implementing intensity interferometry on Imaging Air Cherenkov Telescope arrays. The scientific motivations are varied, including stellar diameter measurements and investigations of the circumstellar environment. Long baselines and short wavelengths are easily accesible to this technique, making it uniquely suited for some applications.

  19. Neutral wind results from TIMED Doppler interferometer

    Science.gov (United States)

    Killeen, T.; Gablehouse, R.; Gell, D.; Johnson, R.; Niciejewski, R.; Ortland, D.; Wu, Q.; Skinner, W.; Solomon, S.; Kafkalidis, J.

    2003-04-01

    Since the launch of the NASA Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite in December 2001, the TIMED Doppler Interferometer (TIDI) has been collecting lower thermosphere and mesospheric data for over a year. After adjustments to the spectral sampling scheme and operational mode, the instrument has been optimized. Efforts have also been made to improve the instrument performance. Preliminary neutral winds from O2 (0-0) have been analyzed. Tidal features and their seasonal variation are shown clearly in the wind data, which are quantitatively consistent with model prediction. We will report our progress on these efforts.

  20. Adaptive Holographic Fiber-Optic Interferometer

    Science.gov (United States)

    Kozhevnikov, Nikolai M.; Lipovskaya, Margarita J.

    1990-04-01

    Interaction of phase-modulated light beams in photorefractive local inertial responce media was analysed. Interaction of this type allows to registrate phase-modulated signals adaptively under low frequency phase disturbtion. The experiments on multimode fiber-optic interferometer with demodulation element based on photorefractive bacteriorhodopsin-doped polimer film are described. As the writing of dynamic phase hologram is an inertial process the signal fluctuations with the frequencies up to 100 Hz can be canceled. The hologram efficiencies are enough to registrate high frequency phase shifts ~10-4 radn.

  1. Low cost Michelson-Morley interferometer

    Science.gov (United States)

    Pathare, Shirish; Kurmude, Vikrant

    2016-11-01

    The Michelson-Morley interferometer is an important and challenging experiment in many undergraduate as well as post-graduate physics laboratories. The apparatus required for this experiment is costly and delicate to handle. It also requires considerable skill to obtain a set of sharp fringes. This frontline presents a low cost (~US50) design of the experiment, which can be easily fabricated in any undergraduate laboratory. It is easy to handle as well as any part of this set up being easily replaced in case of any damage.

  2. Mach-Zehnder interferometer for movement monitoring

    Science.gov (United States)

    Vasinek, Vladimir; Cubik, Jakub; Kepak, Stanislav; Doricak, Jan; Latal, Jan; Koudelka, Petr

    2012-06-01

    Fiber optical interferometers belong to highly sensitive equipments that are able to measure slight changes like distortion of shape, temperature and electric field variation and etc. Their great advantage is that they are insensitive on ageing component, from which they are composed of. It is in virtue of herewith, that there are evaluated no changes in optical signal intensity but number interference fringes. To monitor the movement of persons, eventually to analyze the changes in state of motion we developed method based on analysis the dynamic changes in interferometric pattern. We have used Mach- Zehnder interferometer with conventional SM fibers excited with the DFB laser at wavelength of 1550 nm. It was terminated with optical receiver containing InGaAs PIN photodiode. Its output was brought into measuring card module that performs on FFT of the received interferometer signal. The signal rises with the composition of two waves passing through single interferometer arm. The optical fiber SMF 28e in one arm is referential; the second one is positioned on measuring slab at dimensions of 1x2m. A movement of persons around the slab was monitored, signal processed with FFT and frequency spectra were evaluated. They rose owing to dynamic changes of interferometric pattern. The results reflect that the individual subjects passing through slab embody characteristic frequency spectra, which are individual for particular persons. The scope of measuring frequencies proceeded from zero to 10 kHz. It was also displayed in experiments that the experimental subjects, who walked around the slab and at the same time they have had changed their state of motion (knee joint fixation), embodied characteristic changes in their frequency spectra. At experiments the stability of interferometric patterns was evaluated as from time aspects, so from the view of repeated identical experiments. Two kinds of balls (tennis and ping-pong) were used to plot the repeatability measurements and

  3. Atomic Interferometry with Detuned Counter-Propagating Electromagnetic Pulses

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Ming -Yee [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-09-05

    Atomic fountain interferometry uses atoms cooled with optical molasses to 1 μK, which are then launched in a fountain mode. The interferometer relies on the nonlinear Raman interaction of counter-propagating visible light pulses. We present models of these key transitions through a series of Hamiltonians. Our models, which have been verified against special cases with known solutions, allow us to incorporate the effects of non-ideal pulse shapes and realistic laser frequency or wavevector jitter.

  4. Light-pulse atom interferometric device

    Science.gov (United States)

    Biedermann, Grant; McGuinness, Hayden James Evans; Rakholia, Akash; Jau, Yuan-Yu; Schwindt, Peter; Wheeler, David R.

    2016-03-22

    An atomic interferometric device useful, e.g., for measuring acceleration or rotation is provided. The device comprises at least one vapor cell containing a Raman-active chemical species, an optical system, and at least one detector. The optical system is conformed to implement a Raman pulse interferometer in which Raman transitions are stimulated in a warm vapor of the Raman-active chemical species. The detector is conformed to detect changes in the populations of different internal states of atoms that have been irradiated by the optical system.

  5. Atom chip based generation of entanglement for quantum metrology

    CERN Document Server

    Riedel, Max F; Li, Yun; Hänsch, Theodor W; Sinatra, Alice; Treutlein, Philipp

    2010-01-01

    Atom chips provide a versatile `quantum laboratory on a microchip' for experiments with ultracold atomic gases. They have been used in experiments on diverse topics such as low-dimensional quantum gases, cavity quantum electrodynamics, atom-surface interactions, and chip-based atomic clocks and interferometers. A severe limitation of atom chips, however, is that techniques to control atomic interactions and to generate entanglement have not been experimentally available so far. Such techniques enable chip-based studies of entangled many-body systems and are a key prerequisite for atom chip applications in quantum simulations, quantum information processing, and quantum metrology. Here we report experiments where we generate multi-particle entanglement on an atom chip by controlling elastic collisional interactions with a state-dependent potential. We employ this technique to generate spin-squeezed states of a two-component Bose-Einstein condensate and show that they are useful for quantum metrology. The obser...

  6. New technologies for exoplanet detection with mid-IR interferometers

    Directory of Open Access Journals (Sweden)

    Ksendzov A.

    2011-07-01

    Full Text Available This paper provides an overview of technology development for the Terrestrial Planet Finder Interferometer (TPF-I. TPF-I is a mid-infrared space interferometer being designed with the capability of detecting Earth-like planets in the habitable zones around nearby stars.

  7. A possible approach to improve sensitivity of Michelson interferometer

    CERN Document Server

    Fu, J

    2006-01-01

    We propose a possible approach to achieve an 1/N sensitivity of Michelson interferometer by using a properly designed random phase modulation. Although, the $\\sqrt{N}$ precision improvement might not be achieved due to the complication of the random phase modulation, it can help interferometers such as LIGO to reach higher sensitivity.

  8. Michelson interferometer based interleaver design using classic IIR filter decomposition.

    Science.gov (United States)

    Cheng, Chi-Hao; Tang, Shasha

    2013-12-16

    An elegant method to design a Michelson interferometer based interleaver using a classic infinite impulse response (IIR) filter such as Butterworth, Chebyshev, and elliptic filters as a starting point are presented. The proposed design method allows engineers to design a Michelson interferometer based interleaver from specifications seamlessly. Simulation results are presented to demonstrate the validity of the proposed design method.

  9. A 3D translation stage calibrated with Michelson interferometers

    Science.gov (United States)

    Lin, Hui-Hung; Hung, Kuo-Kai; Wang, Lu-Yu; Su, Wei-Hung

    2016-09-01

    A 3D translation stage which meets the requirement of the next-generation lithography is proposed. The Michelson interferometer is used to evaluate the moving distance for this 3-dimensional translation stage. With the help of Michelson interferometer, accuracy in the order of nanometers is desirable.

  10. Numerical simulation and experimental verification of extended source interferometer

    Science.gov (United States)

    Hou, Yinlong; Li, Lin; Wang, Shanshan; Wang, Xiao; Zang, Haijun; Zhu, Qiudong

    2013-12-01

    Extended source interferometer, compared with the classical point source interferometer, can suppress coherent noise of environment and system, decrease dust scattering effects and reduce high-frequency error of reference surface. Numerical simulation and experimental verification of extended source interferometer are discussed in this paper. In order to provide guidance for the experiment, the modeling of the extended source interferometer is realized by using optical design software Zemax. Matlab codes are programmed to rectify the field parameters of the optical system automatically and get a series of interferometric data conveniently. The communication technique of DDE (Dynamic Data Exchange) was used to connect Zemax and Matlab. Then the visibility of interference fringes can be calculated through adding the collected interferometric data. Combined with the simulation, the experimental platform of the extended source interferometer was established, which consists of an extended source, interference cavity and image collection system. The decrease of high-frequency error of reference surface and coherent noise of the environment is verified. The relation between the spatial coherence and the size, shape, intensity distribution of the extended source is also verified through the analysis of the visibility of interference fringes. The simulation result is in line with the result given by real extended source interferometer. Simulation result shows that the model can simulate the actual optical interference of the extended source interferometer quite well. Therefore, the simulation platform can be used to guide the experiment of interferometer which is based on various extended sources.

  11. Silicon Carbide Mounts for Fabry-Perot Interferometers

    Science.gov (United States)

    Lindemann, Scott

    2011-01-01

    Etalon mounts for tunable Fabry- Perot interferometers can now be fabricated from reaction-bonded silicon carbide structural components. These mounts are rigid, lightweight, and thermally stable. The fabrication of these mounts involves the exploitation of post-casting capabilities that (1) enable creation of monolithic structures having reduced (in comparison with prior such structures) degrees of material inhomogeneity and (2) reduce the need for fastening hardware and accommodations. Such silicon carbide mounts could be used to make lightweight Fabry-Perot interferometers or could be modified for use as general lightweight optical mounts. Heretofore, tunable Fabry-Perot interferometer structures, including mounting hardware, have been made from the low-thermal-expansion material Invar (a nickel/iron alloy) in order to obtain the thermal stability required for spectroscopic applications for which such interferometers are typically designed. However, the high mass density of Invar structures is disadvantageous in applications in which there are requirements to minimize mass. Silicon carbide etalon mounts have been incorporated into a tunable Fabry-Perot interferometer of a prior design that originally called for Invar structural components. The strength, thermal stability, and survivability of the interferometer as thus modified are similar to those of the interferometer as originally designed, but the mass of the modified interferometer is significantly less than the mass of the original version.

  12. An X-ray BBB Michelson interferometer.

    Science.gov (United States)

    Sutter, John P; Ishikawa, Tetsuya; Kuetgens, Ulrich; Materlik, Gerhard; Nishino, Yoshinori; Rostomyan, Armen; Tamasaku, Kenji; Yabashi, Makina

    2004-09-01

    A new X-ray Michelson interferometer based on the BBB interferometer of Bonse and Hart and designed for X-rays of wavelength approximately 1 A was described in a previous paper. Here, a further test carried out at the SPring-8 1 km beamline BL29XUL is reported. One of the BBB's mirrors was displaced by a piezo to introduce the required path-length difference. The resulting variation of intensity with piezo voltage as measured by an avalanche photodiode could be ascribed to the phase variation resulting from the path-length change, with a small additional contribution from the change of the position of the lattice planes of the front mirror relative to the rest of the crystal. This 'Michelson fringe' interpretation is supported by the observed steady movement across the output beam of the interference fringes produced by a refractive wedge when the piezo voltage was ramped. The front-mirror displacement required for one complete fringe at the given wavelength is only 0.675 A; therefore, a quiet environment is vital for operating this device, as previous experiments have shown.

  13. Michelson interferometer for the piezoelectric coefficient measurements

    Directory of Open Access Journals (Sweden)

    Muensit, S.

    2002-01-01

    Full Text Available The present work has described the Michelson interferometer which is capable of measuring the vibrational amplitudes in a sub-angstrom range. In the system, a He-Ne laser is used as a monochromatic source of light and a photodiode as a detector to convert an optical signal into an electronic one. Lock-in detections of the electronic signals are applied to relate the vibrational amplitudes to the wavelength of the laser beam. A feedback circuit is introduced in order to stabilize the sensitivity of the interferometric system. With this setup, a mechanical displacement referred to a change in thickness of a vibrating sample can be measured and the corresponding piezoelectric coefficient, i.e. the ratio of the change in sample thickness to the applied voltage, evaluated. In order to check the performance of the system, measurements on lithium niobate (LiNbO3 have been made and its piezoelectric coefficient d33 was confirmed with 2% accuracy. The piezoelectric coefficient d33 for lead zirconate titanate (PZT ceramics was, therefore, determined by this interferometer and found to be 270 pm/V.

  14. Retrievals with the Infrared Atmospheric Sounding Interferometer

    Science.gov (United States)

    Zhou, Daniel K.; Liu, Xu; Larar, Allen M.; Smith, William L.; Taylor, Jonathan P.; Schlussel, Peter; Strow, L. Larrabee; Calbet, Xavier; Mango, Stephen A.

    2007-01-01

    The Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite was launched on October 19, 2006. The Joint Airborne IASI Validation Experiment (JAIVEx) was conducted during April 2007 mainly for validation of the IASI on the MetOp satellite. IASI possesses an ultra-spectral resolution of 0.25/cm and a spectral coverage from 645 to 2760/cm. Ultraspectral resolution infrared spectral radiance obtained from near nadir observations provide atmospheric, surface, and cloud property information. An advanced retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. Preliminary retrievals of atmospheric soundings, surface properties, and cloud optical/microphysical properties with the IASI observations during the JAIVEx are obtained and presented. These retrievals are further inter-compared with those obtained from airborne FTS system, such as the NPOESS Airborne Sounder Testbed Interferometer (NAST-I), dedicated dropsondes, radiosondes, and ground based Raman Lidar. The capabilities of satellite ultra-spectral sounder such as the IASI are investigated.

  15. The Millimeter-wave Bolometric Interferometer (MBI)

    Science.gov (United States)

    Gault, Amanda C.; Ade, P. A. R.; Bierman, E.; Bunn, E. F.; Hyland, P. O.; Keating, B. G.; Korotkov, A. L.; Malu, S. S.; O'Sullivan, C.; Piccirillo, L.; Timbie, P. T.; Tucker, G. S.

    2009-01-01

    We report on the design and tests of a prototype of the Millimeter-wave Bolometric Interferometer (MBI). MBI is designed to make sensitive measurements of the polarization of the cosmic microwave background (CMB). It combines the differencing capabilities of an interferometer with the high sensitivity of bolometers at millimeter wavelengths. The prototype, which we call MBI-4, views the sky directly through four corrugated horn antennas. MBI ultimately will have 1000 antennas. These antennas have low sidelobes and nearly symmetric beam patterns, so spurious instrumental polarization from reflective optics is avoided. The MBI-4 optical band is defined by filters with a central frequency of 90 GHz. The set of baselines, determined by placement of the four antennas, results in sensitivity to CMB polarization fluctuations over the multipole range l = 150 - 270. The signals are combined with a Fizeau beam combiner and interference fringes are detected by an array of spiderweb bolometers. In order to separate the visibility signals from the total power detected by each bolometer, the phase of the signal from each antenna is modulated by a ferrite-based waveguide phase shifter. Initial tests and observations have been made at Pine Bluff Observatory (PBO) outside Madison, WI. This work was supported by NASA grants NAG5-12758, NNX07AG82G, the Rhode Island Space Grant and the Wisconsin Space Grant.

  16. The Millimeter-Wave Bolometric Interferometer

    Science.gov (United States)

    Korotkov, Andrei; Ade, P. A.; Ali, S.; Bierman, E.; Bunn, E. F.; Calderon, C.; Gault, A. C.; Hyland, P. O.; Keating, B. G.; Kim, J.; Malu, S. S.; Mauskopf, P. D.; Murphy, J. A.; O'Sullivan, C.; Piccirillo, L.; Timbie, P. T.; Tucker, G. S.; Wandelt, B. D.

    2006-12-01

    We report on the status of the Millimeter-Wave Bolometric Interferometer (MBI), an instrument designed for polarization measurements of the cosmic microwave background (CMB). MBI combines the differencing capabilities of an interferometer with the high sensitivity of bolometers. The design of the ground-based four-channel version of the instrument with 7-degree-FOV corrugated horns (MBI-4) and first measurements results are discussed. Corrugated horn antennas with low sidelobes and nearly symmetric beam patterns minimize spurious instrumental polarization. The MBI-4 optical band is limited by filters with a central frequency of 90 GHz. The antenna separation is chosen so the instrument is sensitive over the multipole range l=150-270. In MBI-4, the signals from antennas are combined with a quasi-optical Fizeau beam combiner and interference fringes are detected by an array of spider-web bolometers with NTD germanium thermistors. In order to separate the visibility signals from the total power detected by each bolometer, the phase of the signal from each antenna is modulated by a ferrite-based waveguide phase shifter. First observations will be from the Pine Bluff Observatory outside Madison, WI. The project is supported by NASA.

  17. Monolithic interferometer for high precision radial velocity measurements

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Wang, Ji; Lee, Brian

    2009-08-01

    In high precision radial velocity (RV) measurements for extrasolar planets searching and studies, a stable wide field Michelson interferometer is very critical in Exoplanet Tracker (ET) instruments. Adopting a new design, monolithic interferometers are homogenous and continuous in thermal expansion, and field compensation and thermal compensation are both satisfied. Interferometer design and fabrication are decrypted in details. In performance evaluations, field angle is typically 22° and thermal sensitivity is typically -1.7 x 10-6/°C, which corresponds to ~500 m/s /°C in RV scale. In interferometer stability monitoring using a wavelength stabilized laser source, phase shift data was continuously recorded for nearly seven days. Appling a frequent calibration every 30 minutes as in typical star observations, the interferometer instability contributes less than 1.4 m/s in RV error, in a conservative estimation.

  18. Atomic energy

    CERN Multimedia

    1996-01-01

    Interviews following the 1991 co-operation Agreement between the Department of Atomic Energy (DAE) of the Government of India and the European Organization for Nuclear Research (CERN) concerning the participation in the Large Hadron Collider Project (LHC) . With Chidambaram, R, Chairman, Atomic Energy Commission and Secretary, Department of Atomic Energy, Department of Atomic Energy (DAE) of the Government of India and Professor Llewellyn-Smith, Christopher H, Director-General, CERN.

  19. Atom chips

    CERN Document Server

    Reichel, Jakob

    2010-01-01

    This book provides a stimulating and multifaceted picture of a rapidly developing field. The first part reviews fundamentals of atom chip research in tutorial style, while subsequent parts focus on the topics of atom-surface interaction, coherence on atom chips, and possible future directions of atom chip research. The articles are written by leading researchers in the field in their characteristic and individual styles.

  20. Vortex array laser beam generation from a Dove prism-embedded unbalanced Mach-Zehnder interferometer.

    Science.gov (United States)

    Chu, Shu-Chun; Yang, Chao-Shun; Otsuka, Kenju

    2008-11-24

    This paper proposes a new scheme for generating vortex laser beams from a laser. The proposed system consists of a Dove prism embedded in an unbalanced Mach-Zehnder interferometer configuration. This configuration allows controlled construction of p x p vortex array beams from Ince-Gaussian modes, IG(e) (p,p) modes. An incident IG(e)(p,p) laser beam of variety order p can easily be generated from an end-pumped solid-state laser system with an off-axis pumping mechanism. This study simulates this type of vortex array laser beam generation, analytically derives the vortex positions of the resulting vortex array laser beams, and discusses beam propagation effects. The resulting vortex array laser beam can be applied to optical tweezers and atom traps in the form of two-dimensional arrays, or used to study the transfer of angular momentum to micro particles or atoms (Bose-Einstein condensate).

  1. Atomic polarizabilities

    Energy Technology Data Exchange (ETDEWEB)

    Safronova, M. S. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Mitroy, J. [School of Engineering, Charles Darwin University, Darwin NT 0909 (Australia); Clark, Charles W. [Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, Gaithersburg, Maryland 20899-8410 (United States); Kozlov, M. G. [Petersburg Nuclear Physics Institute, Gatchina 188300 (Russian Federation)

    2015-01-22

    The atomic dipole polarizability governs the first-order response of an atom to an applied electric field. Atomic polarization phenomena impinge upon a number of areas and processes in physics and have been the subject of considerable interest and heightened importance in recent years. In this paper, we will summarize some of the recent applications of atomic polarizability studies. A summary of results for polarizabilities of noble gases, monovalent, and divalent atoms is given. The development of the CI+all-order method that combines configuration interaction and linearized coupled-cluster approaches is discussed.

  2. Atomic vapor spectroscopy in integrated photonic structures

    CERN Document Server

    Ritter, Ralf; Pernice, Wolfram; Kübler, Harald; Pfau, Tilman; Löw, Robert

    2015-01-01

    We investigate an integrated optical chip immersed in atomic vapor providing several waveguide geometries for spectroscopy applications. The narrow-band transmission through a silicon nitride waveguide and interferometer is altered when the guided light is coupled to a vapor of rubidium atoms via the evanescent tail of the waveguide mode. We use grating couplers to couple between the waveguide mode and the radiating wave, which allow for addressing arbitrary coupling positions on the chip surface. The evanescent atom-light interaction can be numerically simulated and shows excellent agreement with our experimental data. This work demonstrates a next step towards miniaturization and integration of alkali atom spectroscopy and provides a platform for further fundamental studies of complex waveguide structures.

  3. Thermal effects in the Input Optics of the Enhanced Laser Interferometer Gravitational-Wave Observatory interferometers.

    Science.gov (United States)

    Dooley, Katherine L; Arain, Muzammil A; Feldbaum, David; Frolov, Valery V; Heintze, Matthew; Hoak, Daniel; Khazanov, Efim A; Lucianetti, Antonio; Martin, Rodica M; Mueller, Guido; Palashov, Oleg; Quetschke, Volker; Reitze, David H; Savage, R L; Tanner, D B; Williams, Luke F; Wu, Wan

    2012-03-01

    We present the design and performance of the LIGO Input Optics subsystem as implemented for the sixth science run of the LIGO interferometers. The Initial LIGO Input Optics experienced thermal side effects when operating with 7 W input power. We designed, built, and implemented improved versions of the Input Optics for Enhanced LIGO, an incremental upgrade to the Initial LIGO interferometers, designed to run with 30 W input power. At four times the power of Initial LIGO, the Enhanced LIGO Input Optics demonstrated improved performance including better optical isolation, less thermal drift, minimal thermal lensing, and higher optical efficiency. The success of the Input Optics design fosters confidence for its ability to perform well in Advanced LIGO.

  4. Ultracold atoms on atom chips

    DEFF Research Database (Denmark)

    Krüger, Peter; Hofferberth, S.; Haller, E.

    2005-01-01

    Miniaturized potentials near the surface of atom chips can be used as flexible and versatile tools for the manipulation of ultracold atoms on a microscale. The full scope of possibilities is only accessible if atom-surface distances can be reduced to microns. We discuss experiments in this regime...

  5. VISAR (Velocity Interferometer System for Any Reflector): Line-imaging interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Hemsing, W.F.; Mathews, A.R.; Warnes, R.H.; Whittemore, G.R.

    1990-01-01

    This paper describes a Velocity Interferometer System for Any Reflector (VISAR) technique that extends velocity measurements from single points to a line. Single-frequency argon laser light was focused through a cylindrical lens to illuminate a line on a surface. The initially stationary, flat surface was accelerated unevenly during the experiment. Motion produced a Doppler-shift of light reflected from the surface that was proportional to the velocity at each point. The Doppler-shifted image of the illuminated line was focused from the surface through a push-pull VISAR interferometer where the light was split into four quadrature-coded images. When the surface accelerated, the Doppler-shift caused the interference for each point on each line image to oscillate sinusoidally. Coherent fiber optic bundles transmitted images from the interferometer to an electronic streak camera for sweeping in time and recording on film. Data reduction combined the images to yield a continuous velocity and displacement history for all points on the surface that reflected sufficient light. The technique was demonstrated in an experiment where most of the surface was rapidly driven to a saddle shape by an exploding foil. Computer graphics were used to display the measured velocity history and to aid visualization of the surface motion. 6 refs., 8 figs.

  6. A Michelson-type radio interferometer for university education

    Science.gov (United States)

    Koda, Jin; Barrett, James; Shafto, Gene; Slechta, Jeff; Hasegawa, Tetsuo; Hayashi, Masahiko; Metchev, Stanimir

    2016-04-01

    We report development of a simple and affordable radio interferometer suitable as an educational laboratory experiment. The design of this interferometer is based on the Michelson and Pease stellar optical interferometer, but instead operates at the radio wavelength of ˜11 GHz (˜2.7 cm), requiring much less stringent optical accuracy in its design and use. We utilize a commercial broadcast satellite dish and feedhorn with two flat side mirrors that slide on a ladder, providing baseline coverage. This interferometer can resolve and measure the diameter of the Sun, even on a day with marginal weather. Commercial broadcast satellites provide convenient point sources for comparison to the Sun's extended disk. The mathematical background of an adding interferometer is presented, as is its design and development, including the receiver system, and sample measurements of the Sun. Results from a student laboratory report are shown. With the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the future generation of astronomers. This interferometer provides the hands-on experience needed to fully understand the basic concepts of interferometry.

  7. TFTR Michelson interferometer electron cyclotron emission diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, F.J.; Boyd, D.A.; Cutler, R.C.; McCarthy, M.P.

    1985-05-01

    In July 1984, a Fourier transform spectrometer employing a fast-scanning Michelson interferometer began operating on TFTR. This diagnostic system can measure the electron cyclotron emission spectrum 72 times per s with a time resolution of 11 ms and a spectral resolution of 3.6 GHz. The initial operating spectral range is 75--540 GHz, which is adequate for measuring the first three cyclotron harmonics at present TFTR magnetic field levels. The range can be extended easily to 75--1080 GHz in order to accommodate increases in toroidal magnetic field or to study superthermal ECE. The measured spectra are absolutely calibrated using a liquid nitrogen cooled blackbody reference source. The second harmonic feature of each spectrum is used to calculate the absolute electron temperature profile.

  8. Distributed acoustic sensing with Michelson interferometer demodulation

    Science.gov (United States)

    Liu, Xiaohui; Wang, Chen; Shang, Ying; Wang, Chang; Zhao, Wenan; Peng, Gangding; Wang, Hongzhong

    2016-12-01

    The distributed acoustic sensing (DAS) has been extensively studied and widely used. A distributed acoustic sensing system based on the unbalanced Michelson interferometer with phase generated carrier (PGC) demodulation was designed and tested. The system could directly obtain the phase, amplitude, frequency response, and location information of sound wave at the same time and measurement at all points along the sensing fiber simultaneously. Experiments showed that the system successfully measured the acoustic signals with a phase-pressure sensitivity about-148 dB (re rad/μPa) and frequency response ripple less than 1.5 dB. The further field experiment showed that the system could measure signals at all points along the sensing fiber simultaneously.

  9. Artificial calibration source for ALMA radio interferometer

    Science.gov (United States)

    Kiuchi, Hitoshi; Hills, Richard; Whyborn, Nicholas D.; Asayama, Shinichiro; Sakamoto, Seiichi; Iguchi, Satoru; Corder, Stuartt A.

    2016-07-01

    The ALMA (Atacama Large Millimeter/submillimeter Array) radio interferometer has some different types of antennas which have a variation of gain and leakages across the primary beam of an individual antenna. We have been developing an artificial calibration source which is used for compensation of individual difference of antennas. In a high-frequency antenna, using astronomical sources to do calibration measurement would be extremely time consuming, whereas with the artificial calibration source becomes a realistic possibility. Photonic techniques are considered to be superior to conventional techniques based on electronic devices in terms of wide bandwidth and high-frequency signals. Conversion from an optical signal to a millimeter/sub-millimeter wave signal is done by a photo-mixer.

  10. Broadband interferometer observations of a triggered lightning

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The development of positive leader of an artificially triggered lightning has been analyzed based on the data of electric field change, location of radiation source and frequency spectrum obtained by using the broadband interferometer system. The results indicate that radiation from positive leader could be detected within close distance in spite of the relatively weak radiation, while the radiation from negative breakdown processes was relatively stronger.Positive leader developed with few branches, and the initial progression velocity was of the order of 10s m/s. The distribution of power spectrum by 25 MHz high pass filter indicated that the radiation frequency from positive leader maximized at 25-30 MHz, while that from negative breakdown processes maximized at 60-70 MHz.

  11. A holographic three-slit interferometer

    Institute of Scientific and Technical Information of China (English)

    王丁; LI; Jingsong

    2002-01-01

    A new type of real-time holographic three-slit interferometer is presented.It uses a calcite polarized optical element to obtain objective light and reference light to record a hologram.Its remarkable feature is to use a beam of fixed slit diffracted light as the reference light to record the lateral slit diffracted wave front,and to use also the same diffracted light as the illuminating light to reconstruct the wave front.This insures the phase distribution of the reconstructed wave front against the influence by the small natural direction drift of the laser beam and also by the tiny external vibration.The stabillity,reliability and measuring accuracy of this apparatus are improved notably.

  12. Distributed acoustic sensing with Michelson interferometer demodulation

    Science.gov (United States)

    Liu, Xiaohui; Wang, Chen; Shang, Ying; Wang, Chang; Zhao, Wenan; Peng, Gangding; Wang, Hongzhong

    2017-09-01

    The distributed acoustic sensing (DAS) has been extensively studied and widely used. A distributed acoustic sensing system based on the unbalanced Michelson interferometer with phase generated carrier (PGC) demodulation was designed and tested. The system could directly obtain the phase, amplitude, frequency response, and location information of sound wave at the same time and measurement at all points along the sensing fiber simultaneously. Experiments showed that the system successfully measured the acoustic signals with a phase-pressure sensitivity about-148 dB (re rad/μPa) and frequency response ripple less than 1.5 dB. The further field experiment showed that the system could measure signals at all points along the sensing fiber simultaneously.

  13. Probabilistic image reconstruction for radio interferometers

    CERN Document Server

    Sutter, P M; McEwen, Jason D; Bunn, Emory F; Karakci, Ata; Korotkov, Andrei; Timbie, Peter; Tucker, Gregory S; Zhang, Le

    2013-01-01

    We present a novel, general-purpose method for deconvolving and denoising images from gridded radio interferometric visibilities using Bayesian inference based on a Gaussian process model. The method automatically takes into account incomplete coverage of the uv-plane and mode coupling due to the beam. Our method uses Gibbs sampling to efficiently explore the full posterior distribution of the underlying signal image given the data. We use a set of widely diverse mock images with a realistic interferometer setup and level of noise to assess the method. Compared to results from a proxy for the CLEAN method we find that in terms of RMS error and signal-to-noise ratio our approach performs better than traditional deconvolution techniques, regardless of the structure of the source image in our test suite. Our implementation scales as O(np log np), provides full statistical and uncertainty information of the reconstructed image, requires no supervision, and provides a robust, consistent framework for incorporating...

  14. Shot Noise in a Mesoscopic Interferometer

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guang-Biao; WANG Shun-Jin; LI Lei

    2006-01-01

    The charge conductance and the shot noise in an Aharonov-Bohm interferometer with double quantum dots embedded and coupled to each other by a capacity are studied in the framework of the equation of motion of Green's flunction.From the impurity Anderson model Hamiltonian,the equations of motion of nonequilibrium Green functions are derived and solved including the effects of two body correlations under Lacrolx's approximation.Our results show that the conductance,the shot noise,and the Fano factor (the ratio of the shot noise to the Poisson noise)as functions of the magnetic flux oscillate with the period of h/e,and their oscillation behaviour is similar to the resuIts of the experiment replacing the capacitive coupling by tunnelling between the two dots.The experiment is suggested to test the results.

  15. Parallel Calibration for Sensor Array Radio Interferometers

    CERN Document Server

    Brossard, Martin; Pesavento, Marius; Boyer, Rémy; Larzabal, Pascal; Wijnholds, Stefan J

    2016-01-01

    In order to meet the theoretically achievable imaging performance, calibration of modern radio interferometers is a mandatory challenge, especially at low frequencies. In this perspective, we propose a novel parallel iterative multi-wavelength calibration algorithm. The proposed algorithm estimates the apparent directions of the calibration sources, the directional and undirectional complex gains of the array elements and their noise powers, with a reasonable computational complexity. Furthermore, the algorithm takes into account the specific variation of the aforementioned parameter values across wavelength. Realistic numerical simulations reveal that the proposed scheme outperforms the mono-wavelength calibration scheme and approaches the derived constrained Cram\\'er-Rao bound even with the presence of non-calibration sources at unknown directions, in a computationally efficient manner.

  16. New experimental results on the interference of the states of the hydrogen atom due to long-range interaction with the metal surface

    NARCIS (Netherlands)

    Kucheryaev, YA; Pal'chikov, VG; Pchelin, YA; Sokolov, YL; Yakovlev, VP

    2005-01-01

    The interference of the 2P state of the hydrogen atom due to unknown long-range interaction with the metal surface (Sokolov effect) has been studied by an atomic interferometer. In contrast to previous experiments, where an atomic beam passed through slits in metal plates, a beam in the presented ex

  17. Search for light scalar dark matter with atomic gravitational wave detectors

    CERN Document Server

    Arvanitaki, Asimina; Hogan, Jason M; Rajendran, Surjeet; Van Tilburg, Ken

    2016-01-01

    We show that gravitational wave detectors based on a type of atom interferometry are sensitive to ultralight scalar dark matter. Such dark matter can cause temporal oscillations in fundamental constants with a frequency set by the dark matter mass, and amplitude determined by the local dark matter density. The result is a modulation of atomic transition energies. This signal is ideally suited to a type of gravitational wave detector that compares two spatially separated atom interferometers referenced by a common laser. Such a detector can improve on current searches for electron-mass or electric-charge modulus dark matter by up to 10 orders of magnitude in coupling, in a frequency band complementary to that of other proposals. It demonstrates that this class of atomic sensors is qualitatively different from other gravitational wave detectors, including those based on laser interferometry. By using atomic-clock-like interferometers, laser noise is mitigated with only a single baseline. These atomic sensors ca...

  18. Stability enhancement by joint phase measurements in a single cold atomic fountain

    CERN Document Server

    Meunier, M; Geiger, R; Guerlin, C; Alzar, C L Garrido; Landragin, A

    2015-01-01

    We propose a method of joint interrogation in a single atom interferometer which overcomes the dead time between consecutive measurements in standard cold atomic fountains. The joint operation enables for a faster averaging of the Dick effect associated with the local oscillator noise in clocks and with vibration noise in cold atom inertial sensors. Such an operation allows achieving the lowest stability limit due to atom shot noise. We demonstrate a multiple joint operation in which up to five clouds of atoms are interrogated simultaneously in a single setup. The essential feature of multiple joint operation, demonstrated here for a micro-wave Ramsey interrogation, can be generalized to go beyond the current stability limit associated with dead times in present-day cold atom interferometer inertial sensors.

  19. Sensitivity of atom interferometry to ultralight scalar field dark matter

    CERN Document Server

    Geraci, Andrew A

    2016-01-01

    We discuss the use of atom interferometry as a tool to search for Dark Matter (DM) composed of ultra-light scalar fields. Previous work on ultra-light DM detection using accelerometers has considered the possibility of equivalence principle violating effects whereby gradients in the dark matter field can directly produce relative accelerations between media of differing composition. In atom interferometers, we find that time-varying phase signals from oscillatory, or dilaton-like, DM can also arise due to changes in the atom rest mass that can occur between light-pulses throughout the interferometer sequence as well as changes in the earth's gravitational field. We estimate that several orders of magnitude of unexplored phase space for light DM fields can be probed with our proposed method.

  20. Sensitivity of Atom Interferometry to Ultralight Scalar Field Dark Matter.

    Science.gov (United States)

    Geraci, Andrew A; Derevianko, Andrei

    2016-12-23

    We discuss the use of atom interferometry as a tool to search for dark matter (DM) composed of virialized ultralight fields (VULFs). Previous work on VULF DM detection using accelerometers has considered the possibility of equivalence-principle-violating effects whereby gradients in the dark matter field can directly produce relative accelerations between media of differing composition. In atom interferometers, we find that time-varying phase signals induced by coherent oscillations of DM fields can also arise due to changes in the atom rest mass that can occur between light pulses throughout the interferometer sequence as well as changes in Earth's gravitational field. We estimate that several orders of magnitude of unexplored phase space for VULF DM couplings can be probed due to these new effects.

  1. New method for gravitational wave detection with atomic sensors.

    Science.gov (United States)

    Graham, Peter W; Hogan, Jason M; Kasevich, Mark A; Rajendran, Surjeet

    2013-04-26

    Laser frequency noise is a dominant noise background for the detection of gravitational waves using long-baseline optical interferometry. Amelioration of this noise requires near simultaneous strain measurements on more than one interferometer baseline, necessitating, for example, more than two satellites for a space-based detector or two interferometer arms for a ground-based detector. We describe a new detection strategy based on recent advances in optical atomic clocks and atom interferometry which can operate at long baselines and which is immune to laser frequency noise. Laser frequency noise is suppressed because the signal arises strictly from the light propagation time between two ensembles of atoms. This new class of sensor allows sensitive gravitational wave detection with only a single baseline. This approach also has practical applications in, for example, the development of ultrasensitive gravimeters and gravity gradiometers.

  2. Detection of elastic waves using stabilized Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Hwan; So, Chul Ho; Kwon, Oh Young Yang [KRISS, Daejeon (Korea, Republic of)

    1993-11-15

    The stabilized Michelson interferometer was developed in order to measure micro-displacement due to the elastic wave propagation. The stabilizer was designed to compensate light path disturbances using the reference mirror driven by piezoelectric actuator. Using stabilizer, the effect of external vibration was reduced and interferometer was satisfied the quadrature condition. As results, the output of photodetector had maximum sensitivity and linearity. The minimum detectable displacement was 0.3 nm at the band width of 10 MHz. The epicentral displacement due to the glass capillary breaks and steel ball drop impact were measured by developed interferometer and compared with the calculated one.

  3. Using the Talbot_Lau_interferometer_parameters Spreadsheet

    Energy Technology Data Exchange (ETDEWEB)

    Kallman, Jeffrey S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-06-04

    Talbot-Lau interferometers allow incoherent X-ray sources to be used for phase contrast imaging. A spreadsheet for exploring the parameter space of Talbot and Talbot-Lau interferometers has been assembled. This spreadsheet allows the user to examine the consequences of choosing phase grating pitch, source energy, and source location on the overall geometry of a Talbot or Talbot-Lau X-ray interferometer. For the X-ray energies required to penetrate scanned luggage the spacing between gratings is large enough that the mechanical tolerances for amplitude grating positioning are unlikely to be met.

  4. EIT Based Gas Detector Design by Using Michelson Interferometer

    Science.gov (United States)

    Abbasian, K.; Rostami, A.; Abdollahi, M. H.

    2011-12-01

    Electromagnetically induced transparency (EIT) is one of the interesting phenomena of light-matter interaction which modifies matter properties for propagation of light. In other words, we can change the absorption and refractive index (RI) in neighborhood of the resonant frequency using EIT. In this paper, we have doped 3-level quantum dots in one of the Michelson Interferometer's mirror and used EIT to change its RI. So, a controllable phase difference between lights in two arms of interferometer is created. Long response time is the main drawback of Michelson interferometer based sensor, which is resolved by this technique.

  5. Monolithic Michelson Interferometer as ultra stable wavelength reference

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2010-07-01

    Ultra-stable Monolithic Michelson interferometer can be an ideal reference for highprecision applications such as RV measurement in planet searching and orbit study. The advantages include wide wavelength range, simple sinusoidal spectral format, and high optical efficiency. In this paper, we report that a monolithic Michelson interferometers has been in-house developed with minimized thermal sensitivity with compensation tuning. With a scanning white light interferometer, the thermal sensitivity is measured ~ 6x10-7/°C at 550 nm and it decreases to zero near 1000 nm. We expect the wideband wavelength reference source to be stabilized better than 0.3 m/s for RV experiments

  6. A compact, robust and versatile moiré interferometer

    Science.gov (United States)

    Mollenhauer, D. H.; Ifju, P. G.; Han, B.

    A moiré interferometer was designed and constructed based on a general system design using a reflective crossed-line diffraction grating to produce the four beams of light necessary for moiré interferometry. The design concept, basic design and tuning procedures are discussed. The important features of the interferometer, i.e. compactness, versatility, polarization insensitivity, relaxed collimation requirements, low laser power and remote optics, are addressed. Several such interferometers have been constructed and successfully applied to engineering problems. These include examining the displacement fields surrounding drilled and preformed holes in composite laminates loaded in tension, and the evaluation of nonhomogeneous behavior in textile composites.

  7. Fourier-transform and global contrast interferometer alignment methods

    Science.gov (United States)

    Goldberg, Kenneth A.

    2001-01-01

    Interferometric methods are presented to facilitate alignment of image-plane components within an interferometer and for the magnified viewing of interferometer masks in situ. Fourier-transforms are performed on intensity patterns that are detected with the interferometer and are used to calculate pseudo-images of the electric field in the image plane of the test optic where the critical alignment of various components is being performed. Fine alignment is aided by the introduction and optimization of a global contrast parameter that is easily calculated from the Fourier-transform.

  8. A new topology for the control of complex interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Rabeling, David S; Gossler, Stefan; Cumpston, Jeffrey; Gray, Malcolm B; McClelland, David E [Centre for Gravitational Physics, Faculty of Science, Australian National University, Canberra, 0200 (Australia)

    2006-04-21

    We discuss a new control topology which will generate control signals for the output optics of complex interferometers operating on a pure dark fringe. Our system, which involves the injection of a modulated control field through the output port of the interferometer, is also compatible with the use of squeezed light. We discuss this topology in the context of the control of an interferometer featuring a variable reflectivity signal recycling mirror and present results from a coupled cavity geometry to demonstrate some of the features.

  9. Atom-Interferometry Constraints on Dark Energy

    Science.gov (United States)

    Mueller, Holger

    2016-03-01

    If dark energy is a light scalar field, it might interact with normal matter. The interactions, however, are suppressed in some leading models, which are thus compatible with current cosmological observations as well as solar-system and laboratory studies. Such suppression typically relies on the scalar's interaction with macroscopic amounts of ordinary matter, but can be bypassed by studying the interaction with individual particles. Using an atom interferometer, we have placed tight constraints on so-called chameleon models, ruling out interaction parameters βM > 4 ×104 . This limit is improved by 2.5 orders of magnitude relative to previous experiments. We have already increased the sensitivity of our interferometer hundredfold and are expecting a new constraint soon. Purpose-built experiments in the lab or on the international space station will completely close the gap and rule out out chameleons and other theories, such as axions, dark photons, symmetrons or f (R) gravity.

  10. The manipulation of atoms and bio-molecules by laser light

    CERN Document Server

    Chu, S

    1998-01-01

    A brief history of the laser cooling and trapping of atoms developed over the past 15 years will be presented. The cooling and trapping technology is already being applied in numerous areas of science and engineering. Applications to be discussed include atomic clocks, atom interferometers, as well as studies in polymer dynamics and protein motion. The talk also includes a video tape of DNA molecules being moved with optical tweezers.

  11. Theoretical analysis on x-ray cylindrical grating interferometer

    CERN Document Server

    Cong, Wenxiang; Wang, Ge

    2015-01-01

    Grating interferometer is a state of art x-ray imaging approach, which can simultaneously acquire information of x-ray attenuation, phase shift, and small angle scattering. This approach is very sensitive to micro-structural variation and offers superior contrast resolution for biological soft tissues. The present grating interferometer often uses flat gratings, with serious limitations in the field of view and the flux of photons. The use of curved gratings allows perpendicular incidence of x-rays on the gratings, and gives higher visibility over a larger field of view than a conventional interferometer with flat gratings. In the study, we present a rigorous theoretical analysis of the self-imaging of curved transmission gratings based on Rayleigh-Sommerfeld diffraction. Numerical simulations have demonstrated the self-imaging phenomenon of cylindrical grating interferometer. The theoretical results are in agreement with the results of numerical simulations.

  12. Web-based Teaching Radio Interferometer for Africa

    Science.gov (United States)

    Carignan, Claude; Libert, Yannick

    2016-10-01

    This presentation describes the web-based Teaching Radio Interferometer being built on the campus of the University of Cape Town, in South Africa, to train the future users of the African VLBI (Very Long Baseline Interferometry) Network (AVN).

  13. Performance evaluation of a thermal Doppler Michelson interferometer system.

    Science.gov (United States)

    Mani, Reza; Dobbie, Steven; Scott, Alan; Shepherd, Gordon; Gault, William; Brown, Stephen

    2005-11-20

    The thermal Doppler Michelson interferometer is the primary element of a proposed limb-viewing satellite instrument called SWIFT (Stratospheric Wind Interferometer for Transport studies). SWIFT is intended to measure stratospheric wind velocities in the altitude range of 15-45 km. SWIFT also uses narrowband tandem etalon filters made of germanium to select a line out of the thermal spectrum. The instrument uses the same technique of phase-stepping interferometry employed by the Wind Imaging Interferometer onboard the Upper Atmosphere Research Satellite. A thermal emission line of ozone near 9 microm is used to detect the Doppler shift due to winds. A test bed was set up for this instrument that included the Michelson interferometer and the etalon filters. For the test bed work, we investigate the behavior of individual components and their combination and report the results.

  14. Increasing the Sensitivity of the Michelson Interferometer through Multiple Reflection

    Science.gov (United States)

    Youn, Woonghee

    Michelson interferometry has been one of the most famous and popular optical interference system for analyzing optical components and measuring optical metrology properties. Typical Michelson interferometer can measure object displacement with wavefront shapes to one half of the laser wavelength. As testing components and devices size reduce to micro and nano dimension, Michelson interferometer sensitivity is not suitable. The purpose of this study is to design and develop the Michelson interferometer using the concept of multiple reflections. This thesis proposes a new and novel design for a multiple reflection interferometer, where the number of reflections does not affect the quality of the interference. Theoretically we show that more than 1000 reflections can be achieved. Experimental results of greater than 100 reflections are presented in this thesis.

  15. Novel double path shearing interferometer in corneal topography measurements

    Science.gov (United States)

    Licznerski, Tomasz J.; Jaronski, Jaroslaw; Kosz, Dariusz

    2005-09-01

    The paper presents an approach for measurements of corneal topography by use of a patent pending double path shearing interferometer (DPSI). Laser light reflected from the surface of the cornea is divided and directed to the inputs of two interferometers. The interferometers use lateral shearing of wavefronts in two orthogonal directions. A tilt of one of the mirrors in each interferometric setup perpendicularly to the lateral shear introduces parallel carrier frequency fringes at the output of each interferometer. There is orthogonal linear polarization of the laser light used in two DPSI. Two images of fringe patters are recorded by a high resolution digital camera. The obtained fringe patterns are used for phase difference reconstruction. The phase of the wavefront was reconstructed by use of algorithms for a large grid based on discrete integration. The in vivo method can also be used for tear film stability measurement, artificial tears and contact lens tests.

  16. Two-interferometers fiber optic sensor for disturbance localization

    Science.gov (United States)

    Zyczkowski, Marek; Ciurapinski, Wieslaw; Kondrat, Marcin

    2005-09-01

    Initial researches of Two-interferometers Fibre Optic Sensor for Disturbance Localization will be presented. The sensor is typically susceptible to environmentally induced mechanical perturbation at low frequencies. The presented sensor consists of two interferometers: Sagnac and Michelson. The Sagnac transfer function is proportional to the product of two factors: firstly the rate of change, dφ/dt, of the optical signal, induced at a point by external disturbance, and secondly the distance between the disturbance point and the Sagnac coil centre. The second interferometer transfer function gives an output proportional to φ. So, if we determine a pulsation ω of the mechanical disturbance from both interferometers output signals, we will be able to localize point where the mechanical disturbance takes place along the fibre by means of simple division of these transfer function. A laboratory arrangement of the sensor and the results of numerical signal processing are also shown.

  17. Development of Methods Precision Length Measurement Using Transported Laser Interferometer

    Science.gov (United States)

    Lavrov, E. A.; Epikhin, V. M.; Mazur, M. M.; Suddenok, Y. A.; Shorin, V. N.

    The paper shows the results of a comparison of a developed transported laser interferometer (TLI) with a measurement interferometer XL-80 Renishaw at the distance 0-60 meters. Testings of a breadboard model of the TLI showed that a difference between the travel measurements of the two interferometers does not exceed 6 μm. The mean value of the difference of indications between the TLI and a Renishaw travel measurer at the distance near 58 m approximately equals to 0,5 μm. Root-mean square deviation of the indications of the interferometers approximately equals to 3 μm. At comparison of the sections with the same name between the TLI and the Renishaw travel measurer, measured at different days, a repeatability of the results for the sections with the same name is noted.

  18. Broadband detuned Sagnac interferometer for future generation gravitational wave astronomy

    CERN Document Server

    Voronchev, N V; Danilishin, S L

    2015-01-01

    Broadband suppression of quantum noise below the Standard Quantum Limit (SQL) becomes a top-priority problem for the future generation of large-scale terrestrial detectors of gravitational waves, as the interferometers of the Advanced LIGO project, predesigned to be quantum-noise-limited in the almost entire detection band, are phased in. To this end, among various proposed methods of quantum noise suppression or signal amplification, the most elaborate approach implies a so-called *xylophone* configuration of two Michelson interferometers, each optimised for its own frequency band, with a combined broadband sensitivity well below the SQL. Albeit ingenious, it is a rather costly solution. We demonstrate that changing the optical scheme to a Sagnac interferometer with weak detuned signal recycling and frequency dependent input squeezing can do almost as good a job, as the xylophone for significantly lower spend. We also show that the Sagnac interferometer is more robust to optical loss in filter cavity, used f...

  19. A naturally stable Sagnac-Michelson nonlinear interferometer

    CERN Document Server

    Lukens, Joseph M; Pooser, Raphael C

    2016-01-01

    Interferometers measure a wide variety of dynamic processes by converting a phase change into an intensity change. Nonlinear interferometers, making use of nonlinear media in lieu of beamsplitters, promise substantial improvement in the quest to reach the ultimate sensitivity limits. Here we demonstrate a new nonlinear interferometer utilizing a single parametric amplifier for mode mixing---conceptually, a nonlinear version of the conventional Michelson interferometer with its arms collapsed together. We observe up to 99.9\\% interference visibility and find evidence for noise reduction based on phase-sensitive gain. Our configuration utilizes fewer components than previous demonstrations and requires no active stabilization, offering new capabilities for practical nonlinear interferometric-based sensors.

  20. Do laser interferometers absorb energy from gravitational waves ?

    CERN Document Server

    Ma, Yiqiu; Zhao, Chunnong; Kells, William

    2014-01-01

    In this paper we discuss the energy interaction between gravitational waves and laser interferom- eter gravitational wave detectors. We show that the widely held view that the laser interferometer gravitational wave detector absorbs no energy from gravitational waves is only valid under the approximation of a frequency-independent optomechanical coupling strength and a pump laser without detuning with respect to the resonance of the interferometer. For a strongly detuned interferometer, the optical-damping dynamics dissipates gravitational wave energy through the interaction between the test masses and the optical ?eld. For a non-detuned interferometer, the frequency-dependence of the optomechanical coupling strength causes a tiny energy dissipation, which is proved to be equivalent to the Doppler friction raised by Braginsky et.al.

  1. Decoupling of a Neutron Interferometer from Temperature Gradients

    CERN Document Server

    Saggu, Parminder; Arif, Muhammad; Cory, David; Haun, Robert; Heacock, Ben; Huber, Michael; Li, Ke; Nsofini, Joachim; Sarenac, Dusan; Shahi, Chandra; Skavysh, Vladimir; Snow, William; Werner, Samuel; Young, Albert; Pushin, Dmitriy

    2016-01-01

    Neutron interferometry enables precision measurements that are typically operated within elaborate, multi-layered facilities which provide substantial shielding from environmental noise. These facilities are necessary to maintain the coherence requirements in a perfect crystal neutron interferometer which is extremely sensitive to local environmental conditions such as temperature gradients across the interferometer, external vibrations, and acoustic waves. The ease of operation and breadth of applications of perfect crystal neutron interferometry would greatly benefit from a mode of operation which relaxes these stringent isolation requirements. Here, the INDEX Collaboration and National Institute of Standards and Technology demonstrates the functionality of a neutron interferometer in vacuum and characterize the use of a compact vacuum chamber enclosure as a means to isolate the interferometer from spatial temperature gradients and time-dependent temperature fluctuations. The vacuum chamber is found to have...

  2. Phase shift in atom interferometry due to spacetime curvature

    CERN Document Server

    Asenbaum, Peter; Kovachy, Tim; Brown, Daniel D; Hogan, Jason M; Kasevich, Mark A

    2016-01-01

    We present a single-source dual atom interferometer and utilize it as a gradiometer for precise gravitational measurements. The macroscopic separation between interfering atomic wave packets (as large as 16 cm) reveals the interplay of recoil effects and gravitational curvature from a nearby Pb source mass. The gradiometer baseline is set by the laser wavelength and pulse timings, which can be measured to high precision. Using a long drift time and large momentum transfer atom optics, the gradiometer reaches a resolution of $3 \\times 10^{-9}$ s$^{-2}$ per shot and measures a 1 rad phase shift induced by the source mass.

  3. Fiber Fabry-Perot interferometer with controllable temperature sensitivity.

    Science.gov (United States)

    Zhang, Xinpu; Peng, Wei; Zhang, Yang

    2015-12-01

    We proposed a fiber taper based on the Fabry-Perot (FP) interferometer structure with controllable temperature sensitivity. The FP interferometer is formed by inserting a segment of tapered fiber tip into the capillary and subsequently splicing the other end of the capillary to a single-mode fiber (SMF), the tapered fiber endface, and the spliced face form the FP cavity. Through controlling the inserted tapered fiber length, a series of FP interferometers were made. Because the inserted taper tip has the degree of freedom along the fiber axial, when the FP interferometer is subjected to temperature variation, the thermal expansion of the fiber taper tip will resist the FP cavity length change caused by the evolution of capillary length, and we can control the temperature sensitivity by adjusting the inserted taper length. In this structure, the equivalent thermal expansion coefficient of the FP interferometer can be defined; it was used to evaluate the temperature sensitivity of the FP interferometer, which provides an effective method to eliminate the temperature effect and to enhance other measurement accuracy. We fabricated the FP interferometers and calibrated their temperature characters by measuring the wavelength shift of the resonance dips in the reflection spectrum. In a temperature range of 50°C to 150°C, the corresponding temperature sensitivities can be controlled between 0 and 1.97 pm/°C when the inserted taper is between 75 and 160 μm. Because of its controllable temperature sensitivity, ease of fabrication, and low cost, this FP interferometer can meet different temperature sensitivity requirements in various application areas, especially in the fields which need temperature insensitivity.

  4. Fiber in-line Michelson Interferometer for refractive index sensing

    Science.gov (United States)

    Liao, C. R.; Wang, D. N.; Wang, Min; Yang, Minghong; Wang, Yiping

    2013-09-01

    A fiber in-line Michelson interferometer based on open micro-cavity is demonstrated, which is fabricated by femtosecond laser micromachining and thin film coating technique. In refractive index sensing, this interferometer operates in a reflection mode of detection, exhibits compact sensor head, good mechanical reliability, wide operation range and high sensitivity of 975nm/RIU (refractive index unit) at the refractive index value of 1.484.

  5. Optical inclinometer based on fibre-taper-modal Michelson interferometer

    Science.gov (United States)

    Amaral, L. M. N.; Frazão, O.; Santos, J. L.; Lobo Ribeiro, A. B.

    2010-09-01

    An inclinometer sensor based on optical fibre-taper-modal Michelson interferometer is demonstrated. The magnitude of the tilt (bending angle of the fibre taper interferometer) is obtained by passive interferometric interrogation based on the generation of two quadrature phase-shifted signals from two fibre Bragg gratings. Optical phase-to-rotation sensitivity of 1.13 rad/degree with a 14 mrad/√Hz resolution is achieved.

  6. Overview and Status of Advanced Interferometers for Gravitational Wave Detection

    OpenAIRE

    Grote, Hartmut

    2016-01-01

    The world-wide network of km-scale laser interferometers is aiming at the detection of gravitational waves of astrophysical origin. The second generation of these instruments, called advanced detectors has been, or is in the process of being completed, and a first observational run with the Advanced LIGO interferometers has been performed late in 2015. The basic functionality of advanced detectors is discussed, along with specific features and status updates of the individual projects.

  7. Overview and Status of Advanced Interferometers for Gravitational Wave Detection

    Science.gov (United States)

    Grote, H.

    2016-05-01

    The world-wide network of km-scale laser interferometers is aiming at the detection of gravitational waves of astrophysical origin. The second generation of these instruments, called advanced detectors has been, or is in the process of being completed, and a first observational run with the Advanced LIGO interferometers has been performed late in 2015. The basic functionality of advanced detectors is discussed, along with specific features and status updates of the individual projects.

  8. Applications of monolithic fiber interferometers and actively controlled fibers

    OpenAIRE

    Rugeland, Patrik

    2013-01-01

    The objective of this thesis was to develop applications of monolithic fiber devices and actively controlled fibers. A special twin-core fiber known as a ‘Gemini’ fiber was used to construct equal arm-length fiber interferometers, impervious to temperature and mechanical perturbations. A broadband add/drop multiplexer was constructed by inscribing fiber Bragg gratings in the arms of a Gemini Mach-Zehnder interferometer. A broadband interferometric nanosecond switch was constructed from a micr...

  9. Atomic physics

    CERN Document Server

    Born, Max

    1989-01-01

    The Nobel Laureate's brilliant exposition of the kinetic theory of gases, elementary particles, the nuclear atom, wave-corpuscles, atomic structure and spectral lines, electron spin and Pauli's principle, quantum statistics, molecular structure and nuclear physics. Over 40 appendices, a bibliography, numerous figures and graphs.

  10. Atomic Calligraphy

    Science.gov (United States)

    Imboden, Matthias; Pardo, Flavio; Bolle, Cristian; Han, Han; Tareen, Ammar; Chang, Jackson; Christopher, Jason; Corman, Benjamin; Bishop, David

    2013-03-01

    Here we present a MEMS based method to fabricate devices with a small number of atoms. In standard semiconductor fabrication, a large amount of material is deposited, after which etching removes what is not wanted. This technique breaks down for structures that approach the single atom limit, as it is inconceivable to etch away all but one atom. What is needed is a bottom up method with single or near single atom precision. We demonstrate a MEMS device that enables nanometer position controlled deposition of gold atoms. A digitally driven plate is swept as a flux of gold atoms passes through an aperture. Appling voltages on four comb capacitors connected to the central plate by tethers enable nanometer lateral precision in the xy plane over 15x15 sq. microns. Typical MEMS structures have manufacturing resolutions on the order of a micron. Using a FIB it is possible to mill apertures as small as 10 nm in diameter. Assuming a low incident atomic flux, as well as an integrated MEMS based shutter with microsecond response time, it becomes possible to deposit single atoms. Due to their small size and low power consumption, such nano-printers can be mounted directly in a cryogenic system at ultrahigh vacuum to deposit clean quench condensed metallic structures.

  11. Highly stable polarization independent Mach-Zehnder interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Mičuda, Michal, E-mail: micuda@optics.upol.cz; Doláková, Ester; Straka, Ivo; Miková, Martina; Dušek, Miloslav; Fiurášek, Jaromír; Ježek, Miroslav, E-mail: jezek@optics.upol.cz [Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 77146 Olomouc (Czech Republic)

    2014-08-15

    We experimentally demonstrate optical Mach-Zehnder interferometer utilizing displaced Sagnac configuration to enhance its phase stability. The interferometer with footprint of 27×40 cm offers individually accessible paths and shows phase deviation less than 0.4° during a 250 s long measurement. The phase drift, evaluated by means of Allan deviation, stays below 3° or 7 nm for 1.5 h without any active stabilization. The polarization insensitive design is verified by measuring interference visibility as a function of input polarization. For both interferometer's output ports and all tested polarization states the visibility stays above 93%. The discrepancy in visibility for horizontal and vertical polarization about 3.5% is caused mainly by undesired polarization dependence of splitting ratio of the beam splitter used. The presented interferometer device is suitable for quantum-information and other sensitive applications where active stabilization is complicated and common-mode interferometer is not an option as both the interferometer arms have to be accessible individually.

  12. A Michelson interferometer for X-rays and thermal neutrons. Ein Michelson-Interferometer fuer Roentgenstrahlen und thermische Neutronen

    Energy Technology Data Exchange (ETDEWEB)

    Appel, A.

    1992-02-17

    The introduced interferometer consists of an LLL interferometer and a phase-displacing Bragg groove component. A part of the radiation path between the Lane mirrors in the Bragg grooves is replaced by a radiation path, whose wave number vector has a slightly different direction compared to the Lane case by the refraction correction. If the angles of incidence in the two grooves are different, then a difference in path is produced between the beams producing interference. This is the first X-ray interferometer which works like an optical Michelson interferometer. As there are no basic limits to resolution by absorption or dispersion, for example, it opens up the possibility of carrying out Fourier spectroscopy in the A wavelength range. (orig.).

  13. Composite pulses for interferometry in a thermal cold atom cloud

    CERN Document Server

    Dunning, Alexander; Bateman, James; Cooper, Nathan; Himsworth, Matthew; Jones, Jonathan A; Freegarde, Tim

    2014-01-01

    Atom interferometric sensors and quantum information processors must maintain coherence while the evolving quantum wavefunction is split, transformed and recombined, but suffer from experimental inhomogeneities and uncertainties in the speeds and paths of these operations. Several error-correction techniques have been proposed to isolate the variable of interest. Here we apply composite pulse methods to velocity-sensitive Raman state manipulation in a freely-expanding thermal atom cloud. We compare several established pulse sequences, and follow the state evolution within them. The agreement between measurements and simple predictions shows the underlying coherence of the atom ensemble, and the inversion infidelity in an 80 micro-Kelvin atom cloud is halved. Composite pulse techniques, especially if tailored for atom interferometric applications, should allow greater interferometer areas, larger atomic samples and longer interaction times, and hence improve the sensitivity of quantum technologies from inertia...

  14. Atom interferometry in the presence of an external test mass

    CERN Document Server

    Dubetsky, B; Libby, S B; Berman, P R

    2016-01-01

    The influence of an external test mass on the phase of the signal of an atom interferometer is studied theoretically. Using traditional techniques in atom optics based on the density matrix equations in the Wigner representation, we are able to extract the various contributions to the phase of the signal associated with the classical motion of the atoms, the quantum correction to this motion resulting from atomic recoil that is produced when the atoms interact with Raman field pulses, and quantum corrections to the atomic motion that occur in the time between the Raman field pulses. By increasing the effective wave vector associated with the Raman field pulses using modified field parameters, we can increase the sensitivity of the signal to the point where the quantum corrections can be measured. The expressions that are derived can be evaluated numerically to isolate the contribution to the signal from an external test mass. The regions of validity of the exact and approximate expressions are determined.

  15. Double diffraction in an atomic gravimeter

    CERN Document Server

    Malossi, Nicola; Merlet, Sébastien; Landragin, Arnaud; Santos, Franck Pereira Dos

    2009-01-01

    We demonstrate the realization of a new scheme for cold atom gravimetry based on the use of double diffraction beamsplitters recently demonstrated in \\cite{Leveque}, where the use of two retro-reflected Raman beams allows symmetric diffraction in $\\pm \\hbar k_{eff}$ momenta. Though in principle restricted to the case of zero Doppler shift, for which the two pairs of Raman beams are simultaneously resonant, we demonstrate that such diffraction pulses can remain efficient on atoms with non zero velocity, such as in a gravimeter, when modulating the frequency of one of the two Raman laser sources. We use such pulses to realize an interferometer insensitive to laser phase noise and some of the dominant systematics. This reduces the technical requirements and would allow the realization of a simple atomic gravimeter. We demonstrate a sensitivity of $1.2\\times10^{-7}g$ per shot.

  16. Magnetometer Based On Spin Wave Interferometer

    CERN Document Server

    Balynsky, M; Chiang, H; Kozhevnikov, A; Filimonov, Y; Balandin, A A; Khitun, A

    2016-01-01

    We describe magnetic field sensor based on spin wave interferometer. Its sensing element consists of a magnetic cross junction with four micro-antennas fabricated at the edges. Two of these antennas are used for spin wave excitation and two others antennas are used for the detection of the inductive voltage produced by the interfering spin waves. Two waves propagating in the orthogonal arms of the cross may accumulate significantly different phase shifts depending on the magnitude and the direction of the external magnetic field. This phenomenon is utilized for magnetic field sensing. The sensitivity has maximum at the destructive interference condition, where a small change of the external magnetic field results in a drastic increase of the inductive voltage as well as the change of the output phase. We report experimental data obtained on a micrometer scale Y3Fe2(FeO4)3 cross structure. The change of the inductive voltage near the destructive interference point exceeds 40 dB per 1 Oe. At the same time, the ...

  17. With the VLT Interferometer towards Sharper Vision

    Science.gov (United States)

    2000-05-01

    The Nova-ESO VLTI Expertise Centre Opens in Leiden (The Netherlands) European science and technology will gain further strength when the new, front-line Nova-ESO VLTI Expertise Centre (NEVEC) opens in Leiden (The Netherlands) this week. It is a joint venture of the Netherlands Research School for Astronomy (NOVA) (itself a collaboration between the Universities of Amsterdam, Groningen, Leiden, and Utrecht) and the European Southern Observatory (ESO). It is concerned with the Very Large Telescope Interferometer (VLTI). The Inauguration of the new Centre will take place on Friday, May 26, 2000, at the Gorlaeus Laboratory (Lecture Hall no. 1), Einsteinweg 55 2333 CC Leiden; the programme is available on the web. Media representatives who would like to participate in this event and who want further details should contact the Nova Information Centre (e-mail: jacques@astro.uva.nl; Tel: +31-20-5257480 or +31-6-246 525 46). The inaugural ceremony is preceded by a scientific workshop on ground and space-based optical interferometry. NEVEC: A Technology Centre of Excellence As a joint project of NOVA and ESO, NEVEC will develop in the coming years the expertise to exploit the unique interferometric possibilities of the Very Large Telescope (VLT) - now being built on Paranal mountain in Chile. Its primary goals are the * development of instrument modeling, data reduction and calibration techniques for the VLTI; * accumulation of expertise relevant for second-generation VLTI instruments; and * education in the use of the VLTI and related matters. NEVEC will develop optical equipment, simulations and software to enable interferometry with VLT [1]. The new Center provides a strong impulse to Dutch participation in the VLTI. With direct involvement in this R&D work, the scientists at NOVA will be in the front row to do observations with this unique research facility, bound to produce top-level research and many exciting new discoveries. The ESO VLTI at Paranal ESO PR Photo 14a/00

  18. ELTS, interferometers, and hypertelescopes at different wavelengths

    Science.gov (United States)

    Labeyrie, Antoine

    2008-04-01

    In the way of major new instruments for ground-based optical astronomy, maximizing the science favors a large hypertelescope. If equipped with adaptive optics and a laser guide star, it can provide direct high-resolution images of faint extra-galactic and cosmological sources. The signal/(photon noise) ratio is theoretically higher than with interferometer schemes relying upon aperture synthesis, using a few large apertures to reconstruct images. The crowding limit on complex objects, the direct-imaging field, and the dynamic range are also improved with many small apertures. The adaptive phasing of hypertelescopes, achievable on bright stars with modified wave sensing techniques such as "dispersed speckle" analysis, is also achievable on very faint sources with a modified version of a laser guide star. This makes large hypertelescopes capable of observing cosmological deep fields of faint galaxies. Pending space versions, the size of which can in principle reach hundreds and thousands of kilometers, terrestrial hypertelescopes limited in size to one or two kilometers can be built at suitable sites and used efficiently from ultra-violet to millimeter wavelengths. Some sites can allow the coupling of a hypertelescope with an ELT, an alternate option which can also be efficient for imaging deep fields with a high-resolution.

  19. The GREGOR Fabry-P\\'erot Interferometer

    CERN Document Server

    Puschmann, K G; Kneer, F; Erdogan, N Al; Balthasar, H; Bauer, S M; Beck, C; González, N Bello; Collados, M; Hahn, T; Hirzberger, J; Hofmann, A; Louis, R E; Nicklas, H; Okunev, O; Pillet, V Martínez; Popow, E; Seelemann, T; Volkmer, R; Wittmann, A D; Woche, M

    2012-01-01

    The GREGOR Fabry-P\\'erot Interferometer (GFPI) is one of three first-light instruments of the German 1.5-meter GREGOR solar telescope at the Observatorio del Teide, Tenerife, Spain. The GFPI uses two tunable etalons in collimated mounting. Thanks to its large-format, high-cadence CCD detectors with sophisticated computer hard- and software it is capable of scanning spectral lines with a cadence that is sufficient to capture the dynamic evolution of the solar atmosphere. The field-of-view (FOV) of 50" x 38" is well suited for quiet Sun and sunspot observations. However, in the vector spectropolarimetric mode the FOV reduces to 25" x 38". The spectral coverage in the spectroscopic mode extends from 530-860 nm with a theoretical spectral resolution R of about 250,000, whereas in the vector spectropolarimetric mode the wavelength range is at present limited to 580-660 nm. The combination of fast narrow-band imaging and post-factum image restoration has the potential for discovery science concerning the dynamic Su...

  20. FIRI - a Far-Infrared Interferometer

    CERN Document Server

    Helmich, Frank

    2007-01-01

    Half of the energy ever emitted by stars and accreting objects comes to us in the FIR waveband and has yet to be properly explored. We propose a powerful Far-InfraRed Interferometer mission, FIRI, to carry out high-resolution imaging spectroscopy in the FIR. This key observational capability is essential to reveal how gas and dust evolve into stars and planets, how the first luminous objects in the Universe ignited, how galaxies formed, and when super-massive black holes grew. FIRI will disentangle the cosmic histories of star formation and accretion onto black holes and will trace the assembly and evolution of quiescent galaxies like our Milky Way. Perhaps most importantly, FIRI will observe all stages of planetary system formation and recognise Earth-like planets that may harbour life, via its ability to image the dust structures in planetary systems. It will thus address directly questions fundamental to our understanding of how the Universe has developed and evolved - the very questions posed by ESA's Cos...

  1. A Quasioptical Vector Interferometer for Polarization Control

    Science.gov (United States)

    Chuss, David T.; Wollack, Edward J.; Moseley, Harvey S.; Novak, Giles

    2005-01-01

    We present a mathematical description of a Quasioptical Vector Interferometer (QVI), a device that maps an input polarization state to an output polarization state by introducing a phase delay between two linear orthogonal components of the input polarization. The advantages of such a device over a spinning wave-plate modulator for measuring astronomical polarization in the far-infrared through millimeter are: 1. The use of small, linear motions eliminates the need for cryogenic rotational bearings, 2. The phase flexibility allows measurement of Stokes V as well as Q and U, and 3. The QVI allows for both multi-wavelength and broadband modulation. We suggest two implementations of this device as an astronomical polarization modulator. The first involves two such modulators placed in series. By adjusting the two phase delays, it is possible to use such a modulator to measure Stokes Q, U, and V for passbands that are not too large. Conversely, a single QVI may be used to measure Q and V independent of frequency. In this implementation, Stokes U must be measured by rotating the instrument. We conclude this paper by presenting initial laboratory results.

  2. Hong-Ou-Mandel atom interferometry in tunnel-coupled optical tweezers

    Science.gov (United States)

    Lester, Brian; Kaufman, Adam; Reynolds, Collin; Wall, Michael; Foss-Feig, Michael; Hazzard, Kaden; Rey, Ana Maria; Regal, Cindy

    2014-05-01

    We present recent work in which we demonstrate near-complete control over all the internal and external degrees of freedom of laser-cooled 87Rb atoms trapped in sub-micron optical tweezers. Utilizing this control for two atoms in two optical tweezers, we implement a massive-particle analog of the Hong-Ou-Mandel interferometer where atom tunneling plays the role of the photon beamsplitter. The interferometer is used to probe the effect of atomic indistinguishability on the two-atom dynamics for a variety of initial conditions. These experiments demonstrate the viability of the optical tweezer platform for bottom-up generation of low-entropy quantum systems and pave the way toward the direct observation of quantum dynamics in more complex finite-sized systems.

  3. Test of the universality of free fall with atoms in different spin Orientations

    CERN Document Server

    Duan, Xiao-Chun; Deng, Xiao-Bing; Yao, Hui-Bin; Shao, Cheng-Gang; Luo, Jun; Hu, and Zhong-Kun

    2015-01-01

    We report a test of the universality of free fall (UFF) related to spin-gravity coupling effects by comparing the gravity acceleration of the $^{87}$Rb atoms in $m_F=+1$ versus that in $m_F=-1$, where the corresponding spin orientations are opposite. A Mach-Zehnder-type atom interferometer is exploited to sequentially measure the free fall acceleration of the atoms in these two sublevels, and the resultant E$\\rm{\\ddot{o}}$tv$\\rm{\\ddot{o}}$s ratio determined by this work is ${\\eta_S} =(-0.2\\pm1.5)\\times 10^{-5}$. The interferometer using atoms in $m_F=+1$ or $m_F=-1$ is highly sensitive to magnetic field inhomogeneity, which limits the current experimental precision of our UFF test. The work here provides a stepping stone for future higher precision UFF test related to different spin orientations on atomic basis.

  4. Development of a combined optical and x-ray interferometer (COXI) system for nanometrology

    Science.gov (United States)

    Yim, Noh B.; Kim, Min Seok; Eom, Cheon I.

    1998-07-01

    In the COXI (Combined Optical and X-ray Interferometer) system, optical and x-ray interferometers are combined to provide a means for the calibration of transducers with the traceability to the standards of length in the sub-nanometer region. The COXI mainly comprises a laser interferometer, an x-ray interferometer, and a precision translation stage. The laser interferometer used for the COXI instrument was a Michelson type, differential heterodyne interferometer having common optical path. A monolithic x-ray interferometer was made from a silicon single crystal. We have designed a control procedure to operate the COXI instrument for the calibration of nano-transducers and developed a phase demodulator for use with the laser interferometer. The bandwidth, phase resolution, and the measurement uncertainty of the interferometer were found 1 kHz, 0.01 degree, and 0.1 degree, respectively.

  5. One Atomic Beam as a Detector of Classical Harmonic Vibrations with Micro Amplitudes and Low Frequencies

    CERN Document Server

    Wong, Werner

    2013-01-01

    We propose a simplest detector of harmonic vibrations with micro amplitudes and low frequencies, i.e. the detector consisting of one atomic beam. Here the atomic beam is induced by a plane harmonic wave and has a classical collective harmonic vibrations, which vibrant directions are perpendicular to the wave vectors of atomic beam. Compared with the detector consisting of atomic Mach-Zehnder interferometer, the new detector has two advantages: (1) it is suitable for the detection of the harmonic vibrations induced either by a longitudinal plane harmonic wave or by a transverse plane harmonic wave; (2) the quantum noise fluctuation of the atomic beam is exactly zero.

  6. Design for a compact CW atom laser

    Science.gov (United States)

    Power, Erik; Raithel, Georg

    2011-05-01

    We present a design for a compact continuous-wave atom laser on a chip. A 2D spiral-shaped quadrupole guide is formed by two 0.5 mm × 0.5 mm wires carrying 5 A each embedded in a Si wafer; a 1.5 mm × 0.5 mm wire on the bottom layer carries -10 A, producing a horizontal B-field that pushes the guiding channel center above the chip surface. The center-to-center separation between the top wires is varied from 1.6 mm at the start of the guide to 1 mm at the end, decreasing the guide height from ~ 500 μm to ~ 25 μm above the surface as the atoms travel the 70 cm-long guide. The magnetic gradient of the guiding channel gradually increases from ~ 100 G /cm to ~ 930 G /cm . These features result in continuous surface adsorption evaporative cooling and progressive magnetic compression. Spin flip losses are mitigated by a solenoid sewn around the guide to produce a longitudinal B-field. 87Rb atoms are gravitationally loaded into the guide. A far off-resonant light shift barrier at the end of the guide traps the atoms and allows formation of a BEC. Tuning the barrier height to create a non-zero tunneling rate equal to the loading rate completes the implementation of a CW atom laser. Two options for atom interferometry are implemented on the first-generation chip (matter-wave Fabry-Perot interferometer and guide-based Mach-Zehnder interferometer). Current construction status and challenges will be discussed, along with preliminary results.

  7. General Relativistic Effects in Atom Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Savas; /Stanford U., Phys. Dept.; Graham, Peter W.; /SLAC /Stanford U., Phys. Dept.; Hogan, Jason M.; Kasevich, Mark A.; /Stanford U., Phys. Dept.

    2008-03-17

    Atom interferometry is now reaching sufficient precision to motivate laboratory tests of general relativity. We begin by explaining the non-relativistic calculation of the phase shift in an atom interferometer and deriving its range of validity. From this we develop a method for calculating the phase shift in general relativity. This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational field for application to laboratory tests of general relativity. The potentially testable relativistic effects include the non-linear three-graviton coupling, the gravity of kinetic energy, and the falling of light. We propose experiments, one currently under construction, that could provide a test of the principle of equivalence to 1 part in 10{sup 15} (300 times better than the present limit), and general relativity at the 10% level, with many potential future improvements. We also consider applications to other metrics including the Lense-Thirring effect, the expansion of the universe, and preferred frame and location effects.

  8. Kinetic Atom.

    Science.gov (United States)

    Wilson, David B.

    1981-01-01

    Surveys the research of scientists like Joule, Kelvin, Maxwell, Clausius, and Boltzmann as it comments on the basic conceptual issues involved in the development of a more precise kinetic theory and the idea of a kinetic atom. (Author/SK)

  9. Application of Thin ZnO ALD Layers in Fiber-Optic Fabry-Pérot Sensing Interferometers.

    Science.gov (United States)

    Majchrowicz, Daria; Hirsch, Marzena; Wierzba, Paweł; Bechelany, Michael; Viter, Roman; Jędrzejewska-Szczerska, Małgorzata

    2016-03-22

    In this paper we investigated the response of a fiber-optic Fabry-Pérot sensing interferometer with thin ZnO layers deposited on the end faces of the optical fibers forming the cavity. Standard telecommunication single-mode optical fiber (SMF-28) segments were used with the thin ZnO layers deposited by Atomic Layer Deposition (ALD). Measurements were performed with the interferometer illuminated by two broadband sources operating at 1300 nm and 1550 nm. Reflected interference signal was acquired by an optical spectrum analyzer while the length of the air cavity was varied. Thickness of the ZnO layers used in the experiments was 50 nm, 100 nm, and 200 nm. Uncoated SMF-28 fiber was also used as a reference. Based on the results of measurements, the thickness of the ZnO layers and the length of the cavity were selected in order to achieve good visibility. Following, the interferometer was used to determine the refractive index of selected liquids.

  10. Application of Thin ZnO ALD Layers in Fiber-Optic Fabry-Pérot Sensing Interferometers

    Directory of Open Access Journals (Sweden)

    Daria Majchrowicz

    2016-03-01

    Full Text Available In this paper we investigated the response of a fiber-optic Fabry-Pérot sensing interferometer with thin ZnO layers deposited on the end faces of the optical fibers forming the cavity. Standard telecommunication single-mode optical fiber (SMF-28 segments were used with the thin ZnO layers deposited by Atomic Layer Deposition (ALD. Measurements were performed with the interferometer illuminated by two broadband sources operating at 1300 nm and 1550 nm. Reflected interference signal was acquired by an optical spectrum analyzer while the length of the air cavity was varied. Thickness of the ZnO layers used in the experiments was 50 nm, 100 nm, and 200 nm. Uncoated SMF-28 fiber was also used as a reference. Based on the results of measurements, the thickness of the ZnO layers and the length of the cavity were selected in order to achieve good visibility. Following, the interferometer was used to determine the refractive index of selected liquids.

  11. "First Light" for the VLT Interferometer

    Science.gov (United States)

    2001-03-01

    Excellent Fringes From Bright Stars Prove VLTI Concept Summary Following the "First Light" for the fourth of the 8.2-m telescopes of the VLT Observatory on Paranal in September 2000, ESO scientists and engineers have just successfully accomplished the next major step of this large project. On March 17, 2001, "First Fringes" were obtained with the VLT Interferometer (VLTI) - this important event corresponds to the "First Light" for an astronomical telescope. At the VLTI, it occurred when the infrared light from the bright star Sirius was captured by two small telescopes and the two beams were successfully combined in the subterranean Interferometric Laboratory to form the typical pattern of dark and bright lines known as " interferometric fringes ". This proves the success of the robust VLTI concept, in particular of the "Delay Line". On the next night, the VLTI was used to perform a scientific measurement of the angular diameter of another comparatively bright star, Alpha Hydrae ( Alphard ); it was found to be 0.00929±0.00017 arcsec . This corresponds to the angular distance between the two headlights of a car as seen from a distance of approx. 35,000 kilometres. The excellent result was obtained during a series of observations, each lasting 2 minutes, and fully confirming the impressive predicted abilities of the VLTI . This first observation with the VLTI is a monumental technological achievement, especially in terms of accuracy and stability . It crucially depends on the proper combination and functioning of a large number of individual opto-mechnical and electronic elements. This includes the test telescopes that capture the starlight, continuous and extremely precise adjustment of the various mirrors that deflect the light beams as well as the automatic positioning and motion of the Delay Line carriages and, not least, the optimal tuning of the VLT INterferometer Commissionning Instrument (VINCI). These initial observations prove the overall concept for the

  12. Controlling the opto-mechanics of a cantilever in an interferometer via cavity loss

    Science.gov (United States)

    von Schmidsfeld, A.; Reichling, M.

    2015-09-01

    In a non-contact atomic force microscope, based on interferometric cantilever displacement detection, the optical return loss of the system is tunable via the distance between the fiber end and the cantilever. We utilize this for tuning the interferometer from a predominant Michelson to a predominant Fabry-Pérot characteristics and introduce the Fabry-Pérot enhancement factor as a quantitative measure for multibeam interference in the cavity. This experimentally easily accessible and adjustable parameter provides a control of the opto-mechanical interaction between the cavity light field and the cantilever. The quantitative assessment of the light pressure acting on the cantilever oscillating in the cavity via the frequency shift allows an in-situ measurement of the cantilever stiffness with remarkable precision.

  13. Controlling the opto-mechanics of a cantilever in an interferometer via cavity loss

    Energy Technology Data Exchange (ETDEWEB)

    Schmidsfeld, A. von, E-mail: avonschm@uos.de; Reichling, M., E-mail: reichling@uos.de [Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49076 Osnabrück (Germany)

    2015-09-21

    In a non-contact atomic force microscope, based on interferometric cantilever displacement detection, the optical return loss of the system is tunable via the distance between the fiber end and the cantilever. We utilize this for tuning the interferometer from a predominant Michelson to a predominant Fabry-Pérot characteristics and introduce the Fabry-Pérot enhancement factor as a quantitative measure for multibeam interference in the cavity. This experimentally easily accessible and adjustable parameter provides a control of the opto-mechanical interaction between the cavity light field and the cantilever. The quantitative assessment of the light pressure acting on the cantilever oscillating in the cavity via the frequency shift allows an in-situ measurement of the cantilever stiffness with remarkable precision.

  14. Decoupling of a neutron interferometer from temperature gradients

    Science.gov (United States)

    Saggu, P.; Mineeva, T.; Arif, M.; Cory, D. G.; Haun, R.; Heacock, B.; Huber, M. G.; Li, K.; Nsofini, J.; Sarenac, D.; Shahi, C. B.; Skavysh, V.; Snow, W. M.; Werner, S. A.; Young, A. R.; Pushin, D. A.

    2016-12-01

    Neutron interferometry enables precision measurements that are typically operated within elaborate, multi-layered facilities which provide substantial shielding from environmental noise. These facilities are necessary to maintain the coherence requirements in a perfect crystal neutron interferometer which is extremely sensitive to local environmental conditions such as temperature gradients across the interferometer, external vibrations, and acoustic waves. The ease of operation and breadth of applications of perfect crystal neutron interferometry would greatly benefit from a mode of operation which relaxes these stringent isolation requirements. Here, the INDEX Collaboration and National Institute of Standards and Technology demonstrates the functionality of a neutron interferometer in vacuum and characterize the use of a compact vacuum chamber enclosure as a means to isolate the interferometer from spatial temperature gradients and time-dependent temperature fluctuations. The vacuum chamber is found to have no depreciable effect on the performance of the interferometer (contrast) while improving system stability, thereby showing that it is feasible to replace large temperature isolation and control systems with a compact vacuum enclosure for perfect crystal neutron interferometry.

  15. Influence of separating distance between atomic sensors for gravitational wave detection

    CERN Document Server

    Tang, Biao; Zhou, Lin; Wang, Jin; Zhan, Mingsheng

    2015-01-01

    We consider a recent scheme of gravitational wave detection using atomic interferometers as inertial sensors, and reinvestigate its configuration using the concept of sensitivity functions. We show that such configuration can suppress noise without influencing the gravitational wave signal. But the suppression is insufficient for the direct observation of gravitational wave signals, so we analyse the behaviour of the different noises influencing the detection scheme. As a novel method, we study the relations between the measurement sensitivity and the distance between two interferometers, and find that the results derived from vibration noise and laser frequency noise are in stark contrast to that derived from the shot noise, which is significant for the configuration design of gravitational wave detectors using atomic interferometers.

  16. Semi-classical description of matter wave interferometers and hybrid quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Mathias

    2015-02-16

    This work considers the semi-classical description of two applications involving cold atoms. This is, on one hand, the behavior of a BOSE-EINSTEIN condensate in hybrid systems, i.e. in contact with a microscopic object (carbon nanotubes, fullerenes, etc.). On the other, the evolution of phase space distributions in matter wave interferometers utilizing ray tracing methods was discussed. For describing condensates in hybrid systems, one can map the GROSS-PITAEVSKII equation, a differential equation in the complex-valued macroscopic wave function, onto a system of two differential equations in density and phase. Neglecting quantum dispersion, one obtains a semiclassical description which is easily modified to incorporate interactions between condensate and microscopical object. In our model, these interactions comprise attractive forces (CASIMIR-POLDER forces) and loss of condensed atoms due to inelastic collisions at the surface of the object. Our model exhibited the excitation of sound waves that are triggered by the object's rapid immersion, and spread across the condensate thereafter. Moreover, local particle loss leads to a shrinking of the bulk condensate. We showed that the total number of condensed particles is decreasing potentially in the beginning (large condensate, strong mean field interaction), while it decays exponentially in the long-time limit (small condensate, mean field inetraction negligible). For representing the physics of matter wave interferometers in phase space, we utilized the WIGNER function. In semi-classical approximation, which again consists in ignoring the quantum dispersion, this representation is subject to the same equation of motion as classical phase space distributions, i.e. the LIOUVILLE equation. This implies that time evolution of theWIGNER function follows a phase space flow that consists of classical trajectories (classical transport). This means, for calculating a time-evolved distribution, one has know the initial

  17. Understanding the dramatic role of anomalous dispersion on the measurement of electron densities in plasmas using interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Nilsen, J; Johnson, W R; Iglesias, C A; Scofield, J H

    2005-07-20

    For decades the electron density of plasmas has been measured using optical interferometers. With the availability of good X-ray laser sources in the last decade interferometers have been extended into the wavelength range 14-47 nm, which has enabled researchers to probe even higher density plasmas. The data analysis assumes the index of refraction is due only to the free electrons, which makes the index less than one. Recent interferometer experiments in Al plasmas observed plasmas with index of refraction greater than one at 14 nm and brought into question the validity of the usual formula for calculating the index. In this paper we show how the anomalous dispersion from bound electrons can dominate the free electron contribution to the index of refraction in many plasmas and make the index greater than one or enhance the contribution to the index such that one would greatly overestimate the density of the plasma using interferometers. Using a new average-atom code we calculate the index of refraction in many plasmas at different temperatures for photon energies from 0 to 100 eV and compare against calculations done with OPAL. We also present examples of other plasmas that may have index of refraction greater than one at X-ray laser energies. During the next decade X-ray free electron lasers and other X-ray sources will be available to probe a wider variety of plasmas at higher densities and shorter wavelengths so understanding the index of refraction in plasmas will be even more essential.

  18. Underground atom gradiometer array for mass distribution monitoring and advanced geodesy

    Science.gov (United States)

    Canuel, B.

    2015-12-01

    After more than 20 years of fundamental research, atom interferometers have reached sensitivity and accuracy levels competing with or beating inertial sensors based on different technologies. Atom interferometers offer interesting applications in geophysics (gravimetry, gradiometry, Earth rotation rate measurements), inertial sensing (submarine or aircraft autonomous positioning), metrology (new definition of the kilogram) and fundamental physics (tests of the standard model, tests of general relativity). Atom interferometers already contributed significantly to fundamental physics by, for example, providing stringent constraints on quantum-electrodynamics through measurements of the hyperfine structure constant, testing the Equivalence Principle with cold atoms, or providing new measurements for the Newtonian gravitational constant. Cold atom sensors have moreover been established as key instruments in metrology for the new definition of the kilogram or through international comparisons of gravimeters. The field of atom interferometry (AI) is now entering a new phase where very high sensitivity levels must be demonstrated, in order to enlarge the potential applications outside atomic physics laboratories. These applications range from gravitational wave (GW) detection in the [0.1-10 Hz] frequency band to next generation ground and space-based Earth gravity field studies to precision gyroscopes and accelerometers. The Matter-wave laser Interferometric Gravitation Antenna (MIGA) presented here is a large-scale matter-wave sensor which will open new applications in geoscience and fundamental physics. The MIGA consortium gathers 18 expert French laboratories and companies in atomic physics, metrology, optics, geosciences and gravitational physics, with the aim to build a large-scale underground atom-interferometer instrument by 2018 and operate it till at least 2023. In this paper, we present the main objectives of the project, the status of the construction of the

  19. Nobel Prize in Physics 1997 "for development of methods to cool and trap atoms with laser light" : Steven Chu, Claude Cohen-Tannoudji and William D. Phillips

    CERN Multimedia

    1998-01-01

    Prof.S. Chu presents "the manipulation of atoms and bio-molecules by laser light" : a brief history of the laser cooling and trapping of atoms developed over the past 15 years will be presented. The cooling and trapping technology is already being applied in numerous areas of science and engineering. Applications to be discussed include atomic clocks, atom interferometers, as well as studies in polymer dynamics and protein motion.

  20. A laser feedback interferometer with an oscillating feedback mirror

    Institute of Scientific and Technical Information of China (English)

    Wang Zhi-Guo; Wang Fei; Xiao Guang-Zong

    2012-01-01

    A method is proposed to solve the problem of direction discrimination for laser feedback interferometers.By vibrating the feedback mirror with a small-amplitude and high-frequency sine wave,laser intensity is modulated accordingly.The modulation amplitude can be extracted using a phase sensitive detector (PSD).When the feedback mirror moves,the PSD output shows a quasi-sine waveform similar to a laser intensity interference fringe but with a phase difference of approximately ±π/2.If the movement direction of the feedback mirror changes,the phase difference sign reverses.Therefore,the laser feedback interferometer offers a potential application in displacement measurement with a resolution of 1/8 wavelength and in-time direction discrimination.Without using optical components such as polarization beam splitters and wave plates,the interferometer is very simple,easy to align,and less costly.

  1. Development of highly sensitive monolithic interferometer for infrared planet search

    Directory of Open Access Journals (Sweden)

    Jiang P.

    2011-07-01

    Full Text Available We present the design, fabrication and testing of a highly sensitive monolithic interferometer for InfraRed Exoplanet Tracker (IR-ET. This interferometer is field-compensated, thermal-stable for working in the wavelength range between 0.8 and 1.35 μm. Two arms of the interferometer creates a fixed delay of 18.0 mm, which is optimized to have the best sensitivity for radial velocity measurements of slow-rotating M dwarfs for planet detection. IR-ET is aiming to reach 3–20 m/s Doppler precision for J<10 M dwarfs in less than 15 min exposures. We plan to conduct a planet survey around hundreds of nearby M dwarfs through collaborations with Astrophysical Research Consortium scientists in 2011–2014.

  2. Scanning Michelson interferometer for imaging surface acoustic wave fields.

    Science.gov (United States)

    Knuuttila, J V; Tikka, P T; Salomaa, M M

    2000-05-01

    A scanning homodyne Michelson interferometer is constructed for two-dimensional imaging of high-frequency surface acoustic wave (SAW) fields in SAW devices. The interferometer possesses a sensitivity of ~10(-5)nm/ radicalHz , and it is capable of directly measuring SAW's with frequencies ranging from 0.5 MHz up to 1 GHz. The fast scheme used for locating the optimum operation point of the interferometer facilitates high measuring speeds, up to 50,000 points/h. The measured field image has a lateral resolution of better than 1 mu;m . The fully optical noninvasive scanning system can be applied to SAW device development and research, providing information on acoustic wave distribution that cannot be obtained by merely electrical measurements.

  3. Finesse, Frequency domain INterferomEter Simulation SoftwarE

    CERN Document Server

    Freise, Andreas; Bond, Charlotte

    2013-01-01

    Finesse is a fast interferometer simulation program. For a given optical setup, it computes the light field amplitudes at every point in the interferometer assuming a steady state. To do so, the interferometer description is translated into a set of linear equations that are solved numerically. For convenience, a number of standard analyses can be performed automatically by the program, namely computing modulation-demodulation error signals, transfer functions, shot-noise-limited sensitivities, and beam shapes. Finesse can perform the analysis using the plane-wave approximation or Hermite-Gauss modes. The latter allows computation of the properties of optical systems like telescopes and the effects of mode matching and mirror angular positions.

  4. Reprint of : Full counting statistics of Majorana interferometers

    Science.gov (United States)

    Strübi, Grégory; Belzig, Wolfgang; Schmidt, Thomas L.; Bruder, Christoph

    2016-08-01

    We study the full counting statistics of interferometers for chiral Majorana fermions with two incoming and two outgoing Dirac fermion channels. In the absence of interactions, the FCS can be obtained from the 4×4 scattering matrix S that relates the outgoing Dirac fermions to the incoming Dirac fermions. After presenting explicit expressions for the higher-order current correlations for a modified Hanbury Brown-Twiss interferometer, we note that the cumulant-generating function can be interpreted such that unit-charge transfer processes correspond to two independent half-charge transfer processes, or alternatively, to two independent electron-hole conversion processes. By a combination of analytical and numerical approaches, we verify that this factorization property holds for a general SO(4) scattering matrix, i.e. for a general interferometer geometry.

  5. A nanofabricated, monolithic, path-separated electron interferometer

    CERN Document Server

    Agarwal, Akshay; Hobbs, Richard; van Dyck, Dirk; Berggren, Karl K

    2016-01-01

    We report a self-aligned, monolithic electron interferometer, consisting of two 45 nm thick silicon layers separated by 20 $\\mu$m. This interferometer was fabricated from a single crystal silicon cantilever on a transmission electron microscope grid by gallium focused ion-beam milling. Using this interferometer, we demonstrate beam path-separation, and obtain interference fringes in a Mach-Zehnder geometry, in an unmodified 200 kV transmission electron microscope. The fringes have a period of 0.32 nm, which corresponds to the $\\left[\\bar{1}\\bar{1}1\\right]$ lattice planes of silicon, and a maximum contrast of 15 %. This design can potentially be scaled to millimeter-scale, and used in electron holography. It can also be applied to perform fundamental physics experiments, such as interaction-free measurement with electrons.

  6. The POLIS interferometer for ponderomotive squeezed light generation

    Science.gov (United States)

    Calloni, Enrico; Conte, Andrea; De Laurentis, Martina; Naticchioni, Luca; Puppo, Paola; Ricci, Fulvio

    2016-07-01

    POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.

  7. Effect of beam quality on tilt measurement using cyclic interferometer

    Science.gov (United States)

    Pretheesh Kumar, V. C.; Ganesan, A. R.; Joenathan, C.; Somasundaram, U.

    2016-08-01

    Accurate measurement of angles is extremely important in various metrological applications. Interferometry has always been an excellent technique for accurate measurements. Several methods have been proposed for accurate tilt measurement using interferometric techniques. Almost all of them use the Michelson configuration which is extremely sensitive to environmental vibrations and turbulences. We know that a cyclic interferometer is extremely stable. Even though it is not sensitive to displacement changes, it is twice sensitive to tilt compared to that of a Michelson interferometer. We have enhanced the sensitivity to measure tilt using multiple reflections in a cyclic interferometer. Since the input beam is collimated, we have studied the effect of aberration of the input beam on the accuracy of tilt measurement. Experimental results on this study are presented in this paper.

  8. The POLIS interferometer for ponderomotive squeezed light generation

    Energy Technology Data Exchange (ETDEWEB)

    Calloni, Enrico [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Conte, Andrea [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); De Laurentis, Martina, E-mail: martina.delaurentis@na.infn.it [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Naticchioni, Luca [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); Puppo, Paola [INFN, Sezione di Roma1 (Italy); Ricci, Fulvio [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy)

    2016-07-11

    POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.

  9. Development of compact cold-atom sensors for inertial navigation

    CERN Document Server

    Battelier, B; Fouché, L; Chichet, L; Antoni-Micollier, L; Porte, H; Napolitano, F; Lautier, J; Landragin, A; Bouyer, P

    2016-01-01

    Inertial sensors based on cold atom interferometry exhibit many interesting features for applications related to inertial navigation, particularly in terms of sensitivity and long-term stability. However, at present the typical atom interferometer is still very much an experiment---consisting of a bulky, static apparatus with a limited dynamic range and high sensitivity to environmental effects. To be compliant with mobile applications further development is needed. In this work, we present a compact and mobile experiment, which we recently used to achieve the first inertial measurements with an atomic accelerometer onboard an aircraft. By integrating classical inertial sensors into our apparatus, we are able to operate the atomic sensor well beyond its standard operating range, corresponding to half of an interference fringe. We report atom-based acceleration measurements along both the horizontal and vertical axes of the aircraft with one-shot sensitivities of $2.3 \\times 10^{-4}\\,g$ over a range of $\\sim 0...

  10. Atom Interferometry for Detection of Gravitational Waves: Progress and Prospects

    Science.gov (United States)

    Hogan, Jason

    2015-04-01

    Gravitational wave astronomy promises to provide a new window into the universe, collecting information about astrophysical systems and cosmology that is difficult or impossible to acquire by other methods. Detector designs based on atom interferometry offer a number of advantages over traditional approaches, including access to conventionally inaccessible frequency ranges and substantially reduced antenna baselines. Atomic physics techniques also make it possible to build a gravitational wave detector with a single linear baseline, potentially offering advantages in cost and design flexibility. In support of these proposals, recent progress in long baseline atom interferometry has enabled observation of matter wave interference with atomic wavepacket separations exceeding 10 cm and interferometer durations of more than 2 seconds. These results are obtained in a 10-meter drop tower incorporating large momentum transfer atom optics. This approach can provide ground-based proof-of-concept demonstrations of many of the technical requirements of both terrestrial and satellite gravitational wave detectors.

  11. Gravitational wave detection using atom interferometry

    Science.gov (United States)

    Hogan, Jason

    2016-05-01

    The advent of gravitational wave astronomy promises to provide a new window into the universe. Low frequency gravitational waves below 10 Hz are expected to offer rich science opportunities both in astrophysics and cosmology, complementary to signals in LIGO's band. Detector designs based on atom interferometry have a number of advantages over traditional approaches in this band, including the possibility of substantially reduced antenna baseline length in space and high isolation from seismic noise for a terrestrial detector. In particular, atom interferometry based on the clock transition in group II atoms offers tantalizing new possibilities. Such a design is expected to be highly immune to laser frequency noise because the signal arises strictly from the light propagation time between two ensembles of atoms. This would allow for a gravitational wave detector with a single linear baseline, potentially offering advantages in cost and design flexibility. In support of these proposals, recent progress in long baseline atom interferometry in a 10-meter drop tower has enabled observation of matter wave interference with atomic wavepacket separations exceeding 50 cm and interferometer durations of more than 2 seconds. This approach can provide ground-based proof-of-concept demonstrations of many of the technical requirements of both terrestrial and satellite gravitational wave detectors.

  12. Atomic theories

    CERN Document Server

    Loring, FH

    2014-01-01

    Summarising the most novel facts and theories which were coming into prominence at the time, particularly those which had not yet been incorporated into standard textbooks, this important work was first published in 1921. The subjects treated cover a wide range of research that was being conducted into the atom, and include Quantum Theory, the Bohr Theory, the Sommerfield extension of Bohr's work, the Octet Theory and Isotopes, as well as Ionisation Potentials and Solar Phenomena. Because much of the material of Atomic Theories lies on the boundary between experimentally verified fact and spec

  13. Parallel Wavefront Analysis for a 4D Interferometer

    Science.gov (United States)

    Rao, Shanti R.

    2011-01-01

    This software provides a programming interface for automating data collection with a PhaseCam interferometer from 4D Technology, and distributing the image-processing algorithm across a cluster of general-purpose computers. Multiple instances of 4Sight (4D Technology s proprietary software) run on a networked cluster of computers. Each connects to a single server (the controller) and waits for instructions. The controller directs the interferometer to several images, then assigns each image to a different computer for processing. When the image processing is finished, the server directs one of the computers to collate and combine the processed images, saving the resulting measurement in a file on a disk. The available software captures approximately 100 images and analyzes them immediately. This software separates the capture and analysis processes, so that analysis can be done at a different time and faster by running the algorithm in parallel across several processors. The PhaseCam family of interferometers can measure an optical system in milliseconds, but it takes many seconds to process the data so that it is usable. In characterizing an adaptive optics system, like the next generation of astronomical observatories, thousands of measurements are required, and the processing time quickly becomes excessive. A programming interface distributes data processing for a PhaseCam interferometer across a Windows computing cluster. A scriptable controller program coordinates data acquisition from the interferometer, storage on networked hard disks, and parallel processing. Idle time of the interferometer is minimized. This architecture is implemented in Python and JavaScript, and may be altered to fit a customer s needs.

  14. White light interferometer: applications in research and industry

    Science.gov (United States)

    Bandyopadhyay, Sujit

    2015-06-01

    Applications of interferometer are countless both in the research and commercial world. Laser sources offer precise measurements of relative path difference between two interfering beams. An exciting example is LIGO (laser Interferometer for Gravitational Observatory), which is aiming to resolve length change as small as 10-19 m over a 4 km length for detection of gravitational waves. However, laser is a disadvantage for microscopic imaging and surface topography applications usually required in semiconductor industry. A different approach for microscopy is to use white light in place of laser. White light due to its limited temporal coherence offers a multitude of benefits for imaging applications. An immediate benefit from white light is the sharp localisation of interference fringe that makes the 3D topography construction or OCT (Optical Coherence Topography) realisable using a Scanning White Light Interferometer (SWLI) imager. In Mirau Mode, SWLI performs high resolution imaging; whereas in Michelson mode Fourier Transform Spectroscopy (FTS) is realised. SWLI can easily be modified into PUPS (Pupil Plane SWLI) for Ellipsometry. Superimposing Michelson Interferometer known as VISAR (Velocity Interferometer System for Any reflector) can form interference fringes even in presence of wide angle light scattered from a moving illuminated object. This paper describes work undertaken at Nanometrics (UK) on simulation of SWLI fringes including high Numerical Aperture (NA) applications, thin film characterisation, OCT generation and Zemax modelling of compact dispersion-free vibration-immune Fourier-Transformed spectrometer. VISAR as a modified Mach-Zehnder Interferometer is also discussed based on the work at Rutherford-Appleton laboratory (UK).

  15. Interferometer-Controlled Optical Tweezers Constructed for Nanotechnology and Biotechnology

    Science.gov (United States)

    Decker, Arthur J.

    2002-01-01

    A new method to control microparticles was developed in-house at the NASA Glenn Research Center in support of the nanotechnology project under NASA's Aerospace Propulsion and Power Base Research Program. A prototype interferometer-controlled optical tweezers was constructed to manipulate scanning probe microscope (SPM) tips. A laser beam passed through a Mach-Zehnder interferometer, and a microscope objective then produced an optical trap from the coaxial beams. The trap levitated and generated the coarse motion of a 10-mm polystyrene sphere used to simulate a SPM tip. The interference between the beams provided fine control of the forces and moments on the sphere. The interferometer included a piezoelectric-scanned mirror to modulate the interference pattern. The 10-mm sphere was observed to oscillate about 1 mm as the mirror and fringe pattern oscillated. The prototype tweezers proved the feasibility of constructing a more sophisticated interferometer tweezers to hold and manipulate SPM tips. The SPM tips are intended to interrogate and manipulate nanostructures. A more powerful laser will be used to generate multiple traps to hold nanostructures and SPM tips. The vibrating mirror in the interferometer will be replaced with a spatial light modulator. The modulator will allow the optical phase distribution in one leg of the interferometer to be programmed independently at 640 by 480 points for detailed control of the forces and moments. The interference patterns will be monitored to measure the motion of the SPM tips. Neuralnetwork technology will provide fast analysis of the interference patterns for diagnostic purposes and for local or remote feedback control of the tips. This effort also requires theoretical and modeling support in the form of scattering calculations for twin coherent beams from nonspherical particles.

  16. Real-time drift error compensation in a self-reference frequency-scanning fiber interferometer

    Science.gov (United States)

    Tao, Long; Liu, Zhigang; Zhang, Weibo; Liu, Zhe; Hong, Jun

    2017-01-01

    In order to eliminate the fiber drift errors in a frequency-scanning fiber interferometer, we propose a self-reference frequency-scanning fiber interferometer composed of two fiber Michelson interferometers sharing common optical paths of fibers. One interferometer defined as reference interferometer is used to monitor the optical path length drift in real time and establish a measurement fixed origin. The other is used as a measurement interferometer to acquire the information from the target. Because the measured optical path differences of the reference and measurement interferometers by frequency-scanning interferometry include the same fiber drift errors, the errors can be eliminated by subtraction of the former optical path difference from the latter optical path difference. A prototype interferometer was developed in our research, and experimental results demonstrate its robustness and stability.

  17. Sinusoidal Phase-Modulating Fabry-Perot Interferometer for Angular Displacement Measurement

    Institute of Scientific and Technical Information of China (English)

    Caini Zhang; Xiangzhao Wang

    2003-01-01

    In this paper, a sinusoidal phase-modulating Fabry-Perot interferometer is proposed to measure angular displacement.The usefulness of the interferometer is demonstrated by simulations and experiments.

  18. Sinusoidal Phase-Modulating Fabry-Perot Interferometer for Angular Displacement Measurement

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, a sinusoidal phase-modulating Fabry-Perot interferometer is proposed to measure angular displacement. The usefulness of the interferometer is demonstrated by simulations and experiments.

  19. The Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Design and Performance Prediction of the Wind and Temperature Instrument on the Ionospheric Connection Explorer (ICON)

    Science.gov (United States)

    Marr, K. D.; Englert, C. R.; Harlander, J.; Brown, C. M.; Stephan, A. W.; Makela, J. J.; Harding, B. J.; Stevens, M. H.; Immel, T. J.

    2014-12-01

    The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) is one of four instruments on the NASA Ionospheric Connection Explorer (ICON). MIGHTI will measure the global distribution of horizontal, neutral winds and temperatures over an altitude range that is not readily accessible to in-situ probes (90-300km). Thermospheric winds will be obtained from Doppler shift measurements of the atomic oxygen green (λ=557.7nm) and red (λ=630.0nm) emission lines. Lower thermospheric temperatures will be determined from the spectral shape of the molecular oxygen atmospheric emission band around λ=762nm. Two identical MIGHTI interferometers, oriented on the spacecraft to view a common atmospheric volume, obtain orthogonal line of sight wind information. Both instruments use the Doppler Asymmetric Spatial Heterodyne (DASH) approach with low order Echelle gratings optimized for the red, green, and near infrared wavelengths detected by MIGHTI. We will present the MIGHTI instrument design, including the driving instrument parameters and performance estimates. In particular, we will show the MIGHTI interferometer design and first laboratory test results using a prototype interferometer.

  20. Detection of Elastic Waves Using Stabilized Michelson Interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. H.; Kwon, O. Y. [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); So, C. H. [Dong Sin University, Gwangju (Korea, Republic of)

    1994-01-15

    The stabilized Michelson interferometer was developed in order to measure micro dynamic displacement at the surface of solids due to elastic wave propagation. The stabilizer was designed to compensate light path disturbances using a reference mirror driven by piezoelectric actuator. Using stabilizer, the effect of external vibration was reduced and the quadrature condition was satisfied. As the results, the output of photodetector had maximum sensitivity and linearity. The minimum detectable displacement was 0.3nm at the band width of 10 MHz. The epicentral displacements due to the glass capillary breaks and the steel ball drop impact were measured using the developed interferometer and the results were compared with the calculated one

  1. A reconfigurable optofluidic Michelson interferometer using tunable droplet grating.

    Science.gov (United States)

    Chin, L K; Liu, A Q; Soh, Y C; Lim, C S; Lin, C L

    2010-04-21

    This paper presents a novel optofluidic Michelson interferometer based on droplet microfluidics used to create a droplet grating. The droplet grating is formed by a stream of plugs in the microchannel with constant refractive index variation. It has a real-time tunability in the grating period through varying the flow rates of the liquids and index variation via different combinations of liquids. The optofluidic Michelson interferometer is highly sensitive and is suitable for the measurement of biomedical and biochemical buffer solutions. The experimental results show that it has a sensitivity of 66.7 nm per refractive index unit (RIU) and a detection range of 0.086 RIU.

  2. Photoacoustic Tomography using a Michelson Interferometer with Quadrature Phase Detection

    CERN Document Server

    Speirs, Rory W

    2013-01-01

    We present a pressure sensor based on a Michelson interferometer, for use in photoacoustic tomography. Quadrature phase detection is employed allowing measurement at any point on the mirror surface without having to retune the interferometer, as is typically required by Fabry-Perot type detectors. This opens the door to rapid full surface detection, which is necessary for clinical applications. Theory relating acoustic pressure to detected acoustic particle displacements is used to calculate the detector sensitivity, which is validated with measurement. Proof-of-concept tomographic images of blood vessel phantoms have been taken with sub-millimeter resolution at depths of several millimeters.

  3. Time Delay Properties of a Fabry-Perot Interferometer

    Institute of Scientific and Technical Information of China (English)

    YUAN Shi; MAN Wei-Ning; YU Jin; GAO Jin-Yue

    2001-01-01

    The time delay properties of a Fabry-Perot interferometer are investigated. We found that the group velocity of light through a Fabry-Perot interferometer can be reduced to 10-4 of the light speed in vacuum and the time delay is 210ns, when the reflectivity is 0.999 and the distance between two mirrors is 1 cm. The system is analogous to the recently proposed one-dimensional photonic band-gap structures with a defect [Zhu et al. Opt.Commun. 174(2000)139].

  4. Near-infrared spectral imaging Michelson interferometer for astronomical applications

    Science.gov (United States)

    Wells, C. W.; Potter, A. E.; Morgan, T. H.

    1980-01-01

    The design and operation of an imaging Michelson interferometer-spectrometer used for near-infrared (0.8 micron to 2.5 microns) spectral imaging are reported. The system employs a rapid scan interferometer modified for stable low resolution (250/cm) performance and a 42 element PbS linear detector array. A microcomputer system is described which provides data acquisition, coadding, and Fourier transformation for near real-time presentation of the spectra of all 42 scene elements. The electronic and mechanical designs are discussed and telescope performance data presented.

  5. An active interferometer-stabilization scheme with linear phase control

    DEFF Research Database (Denmark)

    Vardhan Krishnamachari, Vishnu; Andresen, Esben Ravn; Potma, Eric Olaf

    2006-01-01

    We report a simple and robust computer-based active interferometer stabilization scheme which does not require modulation of the interfering beams and relies on an error signal which is linearly related to the optical path difference. In this setup, a non-collinearly propagating reference laser...... beam stabilizes the interference output of the laser light propagating collinearly through the interferometer. This stabilization scheme enables adjustable phase control with 20 ms switching times in the range from 0.02π radians to 6π radians at 632.8 nm....

  6. High-Visibility Photonic Crystal Fiber Interferometer as Multifunctional Sensor

    Directory of Open Access Journals (Sweden)

    Joel Villatoro

    2013-02-01

    Full Text Available A photonic crystal fiber (PCF interferometer that exhibits record fringe contrast (~40 dB is demonstrated along with its sensing applications. The device operates in reflection mode and consists of a centimeter-long segment of properly selected PCF fusion spliced to single mode optical fibers. Two identical collapsed zones in the PCF combined with its modal properties allow high-visibility interference patterns. The interferometer is suitable for refractometric and liquid level sensing. The measuring refractive index range goes from 1.33 to 1.43 and the maximum resolution is ~1.6 × 10−5.

  7. Rational choices for the wavelengths of a two color interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Jobes, F.C.

    1995-07-01

    If in a two color interferometer for plasma density measurements, the two wavelengths are chosen to have a ratio that is a rational number, and if the signals from each of the wavelengths are multiplied in frequency by the appropriate integer of the rational number and then heterodyned together, the resultant signal will have all effects of component motion nulled out. A phase measurement of this signal will have only plasma density information in it. With CO{sub 2} lasers, it is possible to find suitable wavelength pairs which are close enough to rational numbers to produce an improvement of about 100 in density resolution, compared to standard two color interferometers.

  8. Sensing Atomic Motion from the Zero Point to Room Temperature with Ultrafast Atom Interferometry

    CERN Document Server

    Johnson, K G; Mizrahi, J; Wong-Campos, J D; Monroe, C

    2015-01-01

    We sense the motion of a trapped atomic ion using a sequence of state-dependent ultrafast momentum kicks. We use this atom interferometer to characterize a nearly-pure quantum state with $n=1$ phonon and accurately measure thermal states ranging from near the zero-point energy to $\\bar{n}\\sim 10^4$, with the possibility of extending at least 100 times higher in energy. The complete energy range of this method spans from the ground state to far outside of the Lamb-Dicke regime, where atomic motion is greater than the optical wavelength. These interferometric techniques are useful for characterizing ultrafast entangling gates between multiple trapped ions, and may also be used for sensing electromagnetic fields over a wide dynamic range.

  9. Results from a multi aperture Fizeau interferometer ground testbed: demonstrator for a future space-based interferometer

    Science.gov (United States)

    Baccichet, Nicola; Caillat, Amandine; Rakotonimbahy, Eddy; Dohlen, Kjetil; Savini, Giorgio; Marcos, Michel

    2016-08-01

    In the framework of the European FP7-FISICA (Far Infrared Space Interferometer Critical Assessment) program, we developed a miniaturized version of the hyper-telescope to demonstrate multi-aperture interferometry on ground. This setup would be ultimately integrated into a CubeSat platform, therefore providing the first real demonstrator of a multi aperture Fizeau interferometer in space. In this paper, we describe the optical design of the ground testbed and the data processing pipeline implemented to reconstruct the object image from interferometric data. As a scientific application, we measured the Sun diameter by fitting a limb-darkening model to our data. Finally, we present the design of a CubeSat platform carrying this miniature Fizeau interferometer, which could be used to monitor the Sun diameter over a long in-orbit period.

  10. Observation of spectral interference for any path difference in an interferometer

    CERN Document Server

    Salazar-Serrano, Luis Jose; Torres, Juan P

    2014-01-01

    We report the experimental observation of spectral interference in a Michelson interferometer, regardless of the relationship between the temporal path difference introduced between the arms of the interferometer and the spectral width of the input pulse. This observation is possible by introducing the polarization degree of freedom into a Michelson interferometer using a typical weak value amplification scenario.

  11. Representation-free description of light-pulse atom interferometry including non-inertial effects

    Energy Technology Data Exchange (ETDEWEB)

    Kleinert, Stephan, E-mail: stephan.kleinert@uni-ulm.de [Institut für Quantenphysik and Center for Integrated Quantum Science and Technology (IQST), Universität Ulm, Albert-Einstein-Allee 11, D-89081 Ulm (Germany); Kajari, Endre; Roura, Albert [Institut für Quantenphysik and Center for Integrated Quantum Science and Technology (IQST), Universität Ulm, Albert-Einstein-Allee 11, D-89081 Ulm (Germany); Schleich, Wolfgang P. [Institut für Quantenphysik and Center for Integrated Quantum Science and Technology (IQST), Universität Ulm, Albert-Einstein-Allee 11, D-89081 Ulm (Germany); Texas A& M University Institute for Advanced Study (TIAS), Institute for Quantum Science and Engineering (IQSE) and Department of Physics and Astronomy, Texas A& M University College Station, TX 77843-4242 (United States)

    2015-12-30

    Light-pulse atom interferometers rely on the wave nature of matter and its manipulation with coherent laser pulses. They are used for precise gravimetry and inertial sensing as well as for accurate measurements of fundamental constants. Reaching higher precision requires longer interferometer times which are naturally encountered in microgravity environments such as drop-tower facilities, sounding rockets and dedicated satellite missions aiming at fundamental quantum physics in space. In all those cases, it is necessary to consider arbitrary trajectories and varying orientations of the interferometer set-up in non-inertial frames of reference. Here we provide a versatile representation-free description of atom interferometry entirely based on operator algebra to address this general situation. We show how to analytically determine the phase shift as well as the visibility of interferometers with an arbitrary number of pulses including the effects of local gravitational accelerations, gravity gradients, the rotation of the lasers and non-inertial frames of reference. Our method conveniently unifies previous results and facilitates the investigation of novel interferometer geometries.

  12. Correlation functions formed by a femtosecond pulse interferometer

    NARCIS (Netherlands)

    Cui, M.; Bhattacharya, N.; Urbach, H.P.; Van den berg, S.A.

    2008-01-01

    We experimentally demonstrate that a stabilized femtosecond frequency comb can be applied as a tool for distance measurement. The scheme is based on optical interference between individual pulses in a Michelson type interferometer. The cross-correlation functions between individual pulses with a dis

  13. A Coaxial Cable Fabry-Perot Interferometer for Sensing Applications

    Directory of Open Access Journals (Sweden)

    Ming Luo

    2013-11-01

    Full Text Available This paper reports a novel coaxial cable Fabry-Perot interferometer for sensing applications. The sensor is fabricated by drilling two holes half-way into a coaxial cable. The device physics was described. The temperature and strain responses of the sensor were tested. The measurement error was calculated and analyzed.

  14. Research on beam splitting prism in laser heterodyne interferometer

    Science.gov (United States)

    Fu, Xiu-hua; Xiong, Shi-fu; Kou, Yang; Pan, Yong-gang; Chen, Heng; Li, Zeng-yu; Zhang, Chuan-xin

    2014-08-01

    With the rapid development of optical testing technology, laser heterodyne interferometer has been used more and more widely. As the testing precision requirements continue to increase, the technical prism is an important component of heterodyne interference. The research utilizing thin film technology to improve optical performance of interferometer has been a new focus. In the article, based on the use requirements of interferometer beam splitting prism, select Ta2O5 and SiO2 as high and low refractive index materials respectively, deposit on substrate K9. With the help of TFCalc design software and Needle method, adopting electron gun evaporation and ion assisted deposition, the beam splitting prism is prepared successfully and the ratio of transmittance and reflectance for this beam splitting prism in 500~850 nm band, incident angle 45 degree is 8:2. After repeated tests, solved the difference problem of film deposition process parameters ,controlled thickness monitoring precision effectively and finally prepared the ideal beam splitting prism which is high adhesion and stable optics properties. The film the laser induced damage threshold and it meet the requirements of heterodyne interferometer for use.

  15. Measurement of Refractive Index Using a Michelson Interferometer.

    Science.gov (United States)

    Fendley, J. J.

    1982-01-01

    Describes a novel and simple method of measuring the refractive index of transparent plates using a Michelson interferometer. Since it is necessary to use a computer program when determining the refractive index, undergraduates could be given the opportunity of writing their own programs. (Author/JN)

  16. Broadband and tuned signal recycling with a simple michelson interferometer.

    Science.gov (United States)

    Gray, M B; Stevenson, A J; Bachor, H A; McClelland, D E

    1998-09-01

    We present experimental data on the frequency response of both broadband and tuned signal recycling with a benchtop Michelson interferometer. These data are in excellent agreement with our simple theoretical model. We use in-line modulation to give a control system that provides a high degree of orthogonality between the two servo loops.

  17. Quantitative Phase Determination by Using a Michelson Interferometer

    Science.gov (United States)

    Pomarico, Juan A.; Molina, Pablo F.; D'Angelo, Cristian

    2007-01-01

    The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as…

  18. The Navy Precision Optical Interferometer for SSA Applications: An Update

    Science.gov (United States)

    2014-09-01

    optical interferometers are operating on a routine basis, the Georgia State Center for High Angular Resolution Astronomy (CHARA) located on Mt. Wilson CA...ends etc., involves a new series of observing campaigns, starting this coming middle of October, during the glinting season . We expect to be able to

  19. Fiber-optic Michelson interferometer using an optical power divider.

    Science.gov (United States)

    Imai, M; Ohashi, T; Ohtsuka, Y

    1980-10-01

    A fiber-optic interferometer consisting of a multimode fiber-optical power divider was constructed in the Michelson arrangement and applied to measure a micrometer-order displacement of the vibrating object based on an optical homodyne technique. Improvement in the sensitivity of the apparatus is discussed from the viewpoint of increasing the minimum detectable beat signal.

  20. Sub-angstrom surface metrology with a virtual reference interferometer

    Science.gov (United States)

    Freischlad, Klaus

    2012-09-01

    Non-contact, 3D optical interferometric profilers provide detailed topography measurements of super-smooth surfaces such as hard disk substrates and super-polished optics. However, the contribution of the interferometer system to the measurement can be significant for surfaces with an RMS roughness of one Angstrom and below. Special care must be taken to minimize random noise as well as to remove the systematic instrument error from the measured data. While the random noise can be addressed by low-noise design and averaging of measurements, the systematic instrument error is more difficult to eliminate. In this paper an interferometer configuration is presented that eliminates the mid to higher spatial frequencies from the reference beam. This configuration is called a virtual-reference interferometer, since there is no physical surface in focus conjugate to the test surface. This provides very smooth systematic instrument errors with essentially no contribution in the mid to high spatial frequencies of surface waviness and roughness. The virtual-reference interferometer has a midsize measurement area of 20x20 mm, is fully compensated for white light, extended source illumination, and enables data acquisition for both phase shifting and coherence scanning modes. Current performance data show a residual systematic tool waviness error of < 0.2 Angstrom RMS, with potential for improvement. Efficient stitching of subaperture measurements accommodates high resolution roughness and waviness maps of test surfaces up to 150 mm x100 mm.

  1. A compact high-sensitivity heterodyne interferometer for industrial metrology

    Science.gov (United States)

    Schuldt, Thilo; Gohlke, Martin; Weise, Dennis; Peters, Achim; Johann, Ulrich; Braxmaier, Claus

    2008-04-01

    For translation and tilt metrology, we developed a compact fiber-coupled polarizing heterodyne interferometer which is based on a highly symmetric design where both, measurement and reference beam have similar optical pathlengths and the same frequency and polarization. The method of differential wavefront sensing is implemented for tilt measurement. With this setup we reached noise levels below 5 pm/square root of Hz; Hz in translation and below 10 nrad/square root of Hz; in tilt measurement, both for frequencies above 10-2 Hz. While this setup is developed with respect to the requirements of the LISA (Laser Interferometer Space Antenna) space mission, we here present the current status of its adoption to industrial applications. We currently design a very compact and quasi-monolithic setup of the interferometer sensor head based on ultra-low expansion glass material. The resulting compact and robust sensor head can be used for nano-positioning control. We also plan to implement a scan of the measurement beam over the surface under investigation enabling high resolution 3D profilometry and surface property measurements (i. e. roughness, evenness and roundness). The dedicated low-noise (piezo-electric actuator in the measurement beam of the interferometer will be realized using integrated micro-system technology and can either be implemented in one or two dimensions.

  2. Dual interferometer for dynamic measurement of corneal topography

    Science.gov (United States)

    Micali, Jason D.; Greivenkamp, John E.

    2016-08-01

    The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface, where the majority of refraction takes place in the eye. A significant component of vision quality is determined by the shape of the cornea and stability of the tear film. A dual interferometer system for measuring the dynamic corneal topography is designed, built, verified, and qualified by testing on human subjects. The system consists of two coaligned simultaneous phase-shifting polarization-splitting Twyman-Green interferometers. The primary interferometer measures the surface of the tear film while the secondary interferometer tracks the absolute position of the cornea, which provides enough information to reconstruct the absolute shape of the cornea. The results are high-resolution and high-accuracy surface topography measurements of the in vivo tear film and cornea that are captured at standard camera frame rates.

  3. Measurement and Calibration of PSD with Phase-shifting Interferometers

    Science.gov (United States)

    Lehan, J. P.

    2008-01-01

    We discuss the instrumental aspects affecting the measurement accuracy when determining PSD with phase shifting interferometers. These include the source coherence, optical train effects, and detector effects. The use of a carefully constructed calibration standard will also be discussed. We will end with a recommended measurement and data handling procedure.

  4. Development of Monolithic Michelson Interferometer for RV measurement in IR

    Science.gov (United States)

    Wang, Ji; Wan, Xiaoke; Ge, Jian C.

    2010-07-01

    We present a fixed delay interferometer to be installed in IR-ET (Infra-Red Exoplanets Tracker). We introduce the design, fabrication and testing processes. In particular, we present a new methodology of computing the fundamental limit of radial velocity (RV) measurement given by photon noise for DFDI (Dispersed Fixed Delay Interferometer) method as opposed to conventional echelle method. The new method is later used to determine the optical path difference (OPD) of the IR-ET interferometer. In addition, we introduce a novel method of monitoring the stability of the interferometer for IR-ET in broad-band using fourier-transform white-light scanning interferometry technique. The new method can be potentially expanded and applied to thermo-optic effect measurement if temperature control system is introduced into the experiment. The thermal response of the optical system is 3500 m/s/°C. We find that the RV calibration precision of 'Bracketing' method is 1.74 m/s without temperature control.

  5. Dual-frequency laser displacement and angle interferometer

    Science.gov (United States)

    Zhao, Shijie; Wei, Haoyun; Li, Yan

    2014-11-01

    Traditional laser angular interferometers based on a Michelson Interferometer or its modifications have the same principle: changing the angle displacement to an optical path difference. However, measuring the angular error of stage travels is a dynamic process. The main trouble is lack of displacement information and need to be solved urgently. A obvious method is using two dual-frequency interferometers to get the displacement and angular. In this paper, a new kind of displacement and angle interferometer (DIAI) is introduced. In this DIAI, displacement and angular are measured simultaneously by special optical path. The DIAI consists of a stabilized orthogonal polarization dualfrequency laser, a monolithic prism and additional optical and electronic components. The dual-frequency laser is divided into reference light and measurement light by a beam-splitting prism. The measurement light spatially separated into horizontal polarized light and vertical polarized light by the polarization splitting prism. Changing by a fixed 45°- tilted reflector, the vertical polarized light is parallel to the horizontal polarized light. These parallel lights reflected by two corner cube retroreflectors at a moving target. Compared with the reference light, the displacement and angular are measured. Different from the traditional method, there is only one reference corner cube retroreflector in this system. Thus, the angular measurement accuracy is better. The accuracy of the DIAI is better than +/-0.25 arcsec in comparison with an autocollimator.

  6. The USNO/NRL Green Bank interferometer program

    Science.gov (United States)

    Klepczynski, W. J.; Kaplan, G. H.; Mccarthy, D. D.; Josties, F. J.; Branham, R. L.; Johnston, K. J.; Spencer, J. S.

    1980-01-01

    Application of the connected-element radio interferometer of the National Radio Astronomy Observation in Green Bank, West Virginia to the determination of improved source coordinates, astronomical constants, and variations in Earth rotation parameters is discussed. It is concluded that because of the brevity and discontinuity of the data so far no reliable conclusions regarding the accuracy of the data can be drawn.

  7. Determination of transfer function of COPE correlation interferometer instrument

    Science.gov (United States)

    Twitty, J.; Kindle, E. C.

    1976-01-01

    The comparison of theoretical and instrument response functions and its use as a procedure for determining the transfer function of the COPE correlation interferometer are summarized. Data show qualitative agreement can be obtained when discrepancies between theory and instrument are investigated and instrument components are analyzed in detail. Data were obtained using a set of calibration data and computer algorithms.

  8. Variable Free Spectral Range Spherical Mirror Fabry-Perot Interferometer

    CERN Document Server

    Kerner, K; Yashchuk, V V; Budker, D; Kerner, Katherine; Rochester, Simon M.; Yashchuk, Valeriy V.

    2003-01-01

    A spherical Fabry-Perot interferometer with adjustable mirror spacing is used to produce interference fringes with frequency separation (c/2L)/N, N=2-15. The conditions for observation of these fringes are derived from the consideration of the eigenmodes of the cavity with high transverse indices.

  9. Fast phase stabilization of a low frequency beat note for atom interferometry.

    Science.gov (United States)

    Oh, E; Horne, R A; Sackett, C A

    2016-06-01

    Atom interferometry experiments rely on the ability to obtain a stable signal that corresponds to an atomic phase. For interferometers that use laser beams to manipulate the atoms, noise in the lasers can lead to errors in the atomic measurement. In particular, it is often necessary to actively stabilize the optical phase between two frequency components of the beams. Typically this is achieved using a time-domain measurement of a beat note between the two frequencies. This becomes challenging when the frequency difference is small and the phase measurement must be made quickly. The method presented here instead uses a spatial interference detection to rapidly measure the optical phase for arbitrary frequency differences. A feedback system operating at a bandwidth of about 10 MHz could then correct the phase in about 3 μs. This time is short enough that the phase correction could be applied at the start of a laser pulse without appreciably degrading the fidelity of the atom interferometer operation. The phase stabilization system was demonstrated in a simple atom interferometer measurement of the (87)Rb recoil frequency.

  10. Atomic rivals

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmidt, B.

    1990-01-01

    This book is a memoir of rivalries among the Allies over the bomb, by a participant and observer. Nuclear proliferation began in the uneasy wartime collaboration of the United States, England, Canada, and Free France to produce the atom bomb. Through the changes of history, a young French chemist had a role in almost every act of this international drama. This memoir is based on Goldschmidt's own recollections, interviews with other leading figures, and 3,000 pages of newly declassified documents in Allied archives. From his own start as Marie Curie's lab assistant, Goldschmidt's career was closely intertwined with Frances complicated rise to membership in the nuclear club. As a refugee from the Nazis, he became part of the wartime nuclear energy project in Canada and found himself the only French scientist to work (although briefly) on the American atom bomb project.

  11. Atomic physics

    Energy Technology Data Exchange (ETDEWEB)

    Livingston, A.E.; Kukla, K.; Cheng, S. [Univ. of Toledo, OH (United States)] [and others

    1995-08-01

    In a collaboration with the Atomic Physics group at Argonne and the University of Toledo, the Atomic Physics group at the University of Notre Dame is measuring the fine structure transition energies in highly-charged lithium-like and helium-like ions using beam-foil spectroscopy. Precise measurements of 2s-2p transition energies in simple (few-electron) atomic systems provide stringent tests of several classes of current atomic- structure calculations. Analyses of measurements in helium-like Ar{sup 16+} have been completed, and the results submitted for publication. A current goal is to measure the 1s2s{sup 3}S{sub 1} - 1s2p{sup 3}P{sub 0} transition wavelength in helium-like Ni{sup 26+}. Measurements of the 1s2s{sup 2}S{sub 1/2} - 1s2p{sup 2}P{sub 1/2,3/2} transition wavelengths in lithium-like Kr{sup 33+} is planned. Wavelength and lifetime measurements in copper-like U{sup 63+} are also expected to be initiated. The group is also participating in measurements of forbidden transitions in helium-like ions. A measurement of the lifetime of the 1s2s{sup 3}S{sub 1} state in Kr{sup 34+} was published recently. In a collaboration including P. Mokler of GSI, Darmstadt, measurements have been made of the spectral distribution of the 2E1 decay continuum in helium-like Kr{sup 34+}. Initial results have been reported and further measurements are planned.

  12. Quantum metrology with cold atomic ensembles

    Directory of Open Access Journals (Sweden)

    Mitchell Morgan W.

    2013-08-01

    Full Text Available Quantum metrology uses quantum features such as entanglement and squeezing to improve the sensitivity of quantum-limited measurements. Long established as a valuable technique in optical measurements such as gravitational-wave detection, quantum metrology is increasingly being applied to atomic instruments such as matter-wave interferometers, atomic clocks, and atomic magnetometers. Several of these new applications involve dual optical/atomic quantum systems, presenting both new challenges and new opportunities. Here we describe an optical magnetometry system that achieves both shot-noise-limited and projection-noise-limited performance, allowing study of optical magnetometry in a fully-quantum regime [1]. By near-resonant Faraday rotation probing, we demonstrate measurement-based spin squeezing in a magnetically-sensitive atomic ensemble [2-4]. The versatility of this system allows us also to design metrologically-relevant optical nonlinearities, and to perform quantum-noise-limited measurements with interacting photons. As a first interaction-based measurement [5], we implement a non-linear metrology scheme proposed by Boixo et al. with the surprising feature of precision scaling better than the 1/N “Heisenberg limit” [6].

  13. Phase-locked laser diode interferometer: high-speed feedback control system.

    Science.gov (United States)

    Suzuki, T; Sasaki, O; Higuchi, K; Maruyama, T

    1991-09-01

    We have previously proposed a phase-locked laser diode interferometer. In that previous interferometer, however, there was substantial room for improvement in the reduction of measurement time. This reduction is achieved by using a different process for generation of the feedback signal in which the output of a chargecoupled device image sensor is used effectively. We analyze the feedback control system of the interferometer as a discrete-time system and discuss the characteristics of the interferometer. It is shown that the measurement time is much shorter than that of the interferometer proposed previously.

  14. Overview of the control system for the Keck Interferometer

    Science.gov (United States)

    Booth, Andrew J.; Eychaner, Glenn; Hovland, Erik; Johnson, Richard L., Jr.; Lupton, William; Niessner, Al; Palmer, Dean L.; Reder, Leonard J.; Rudeen, Andy C.; Smythe, Robert F.; Tsubota, Kevin

    2002-12-01

    The Keck Interferometer links the two 10m Keck Telescopes located atop Mauna Kea in Hawaii. It is the first 10m class, fully AO equipped interferometer to enter operation. Further, it is the first large interferometer designed to be handed over from a design and implementation team to a separate operations team, and be used by astronomers who are not interferometer specialists. As such it offers unique challenges in reducing an extremely complex and powerful system to an apparently simple user interface, and providing a well engineered system that can be maintained by people who did not develop it. This paper gives an overview of the control system that has been implemented for the single baseline operation of the instrument, and indicates how this will be extended to allow control of the future modes of the instrument (nulling, differential phase and astrometry). The control system has several parts. One is for control of "slow" sub-systems, which is based in the EPICS architecture, already ubiquitous at the Keck Observatory. Another, used to control hard real time sub-systems, is based on a new infrastructure developed at JPL, programmed in C++, Java, and using CORBA for communication. This infrastructure has been developed specifically with the problems of interferometric control in mind and is used in JPL's flight testbeds as well as the Keck Interferometer. Finally, a user interface and high level control layer is in development using a variety of tools including UML based modeling in the Rhapsody tool (using C++ and CORBA), Java, and Tcl/Tk for prototyping.

  15. Four beam interferometer manual: Operating instructions for the INEL diffraction Moire interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Deason, V.A.

    1993-11-01

    Moire interferometry is an interferometric method for measuring changes of in-plane geometry. It is essentially insensitive to out-of-plane topography or changes in that topography. Changes in geometry are referenced to a particular moment in time when the moire` sensor, a diffraction grating, was attached to the specimen. Distortions experienced by the specimen prior to that time are not directly detectable, although they may be inferred from specimen behavior or condition. In its most common form, moire interferometry is not well suited to large (> 50 mm square), curved (< 300 mm diameter) or high temperature (> 200 C) regions. However, various efforts have been made to handle each of these conditions. In general, the moire` process is most straightforward for flat, 25 mm diameter regions of coverage and room temperature. Much smaller or larger regions require more specialized optics, which can become very expensive. This report will discuss various aspects of moire interferometry. In particular, a new four beam (bi-axial) interferometer is described in detail. Issues involved in safety, assembly, calibration and use are fully explained.

  16. An Inexpensive Field-Widened Monolithic Michelson Interferometer for Precision Radial Velocity Measurements

    CERN Document Server

    Mahadevan, Suvrath; Fleming, Scott W; Wan, Xiaoke; DeWitt, Curtis; van Eyken, Julian C; McDavitt, Dan

    2008-01-01

    We have constructed a thermally compensated field-widened monolithic Michelson interferometer that can be used with a medium-resolution spectrograph to measure precise Doppler radial velocities of stars. Our prototype monolithic fixed-delay interferometer is constructed with off-the-shelf components and assembled using a hydrolysis bonding technique. We installed and tested this interferometer in the Exoplanet Tracker (ET) instrument at the Kitt Peak 2.1m telescope, an instrument built to demonstrate the principles of dispersed fixed delay interferometry. An iodine cell allows the interferometer drift to be accurately calibrated, relaxing the stability requirements on the interferometer itself. When using our monolithic interferometer, the ET instrument has no moving parts (except the iodine cell), greatly simplifying its operation. We demonstrate differential radial velocity precision of a few m s$^{-1}$ on well known radial velocity standards and planet bearing stars when using this interferometer. Such mon...

  17. The Atomic orbitals of the topological atom

    OpenAIRE

    Ramos-Cordoba, Eloy; Salvador Sedano, Pedro

    2013-01-01

    The effective atomic orbitals have been realized in the framework of Bader's atoms in molecules theory for a general wavefunction. This formalism can be used to retrieve from any type of calculation a proper set of orthonormalized numerical atomic orbitals, with occupation numbers that sum up to the respective Quantum Theory of Atoms in Molecules (QTAIM) atomic populations. Experience shows that only a limited number of effective atomic orbitals exhibit significant occupation numbers. These c...

  18. Low noise amplication of an optically carried microwave signal: application to atom interferometry

    CERN Document Server

    Lévèque, Thomas; Chaibi, Walid; Landragin, Arnaud

    2010-01-01

    In this paper, we report a new scheme to amplify a microwave signal carried on a laser light at $\\lambda$=852nm. The amplification is done via a semiconductor tapered amplifier and this scheme is used to drive stimulated Raman transitions in an atom interferometer. Sideband generation in the amplifier, due to self-phase and amplitude modulation, is investigated and characterized. We also demonstrate that the amplifier does not induce any significant phase-noise on the beating signal. Finally, the degradation of the performances of the interferometer due to the amplification process is shown to be negligible.

  19. Low noise amplification of an optically carried microwave signal: application to atom interferometry

    Science.gov (United States)

    Lévèque, T.; Gauguet, A.; Chaibi, W.; Landragin, A.

    2010-12-01

    In this paper, we report a new scheme to amplify a microwave signal carried on a laser light at λ=852 nm. The amplification is done via a semiconductor tapered amplifier and this scheme is used to drive stimulated Raman transitions in an atom interferometer. Sideband generation in the amplifier, due to self-phase and amplitude modulation, is investigated and characterized. We also demonstrate that the amplifier does not induce any significant phase-noise on the beating signal. Finally, the degradation of the performances of the interferometer due to the amplification process is shown to be negligible.

  20. Dynamical and non-additive atomic van der Waals phases

    CERN Document Server

    Impens, François; Neto, Paulo A Maia

    2013-01-01

    We investigate dynamical corrections to the van der Waals phase induced by the non-unitary evolution of atomic waves propagating near a perfectly conducting surface. These corrections reflect the interplay between field retardation effects and the dynamics of the external atomic degrees of freedom. The dynamical atom-surface interaction phase shift contains both local and non-local contributions. We derive the local contributions and show that they are equivalent to coarse-graining the instantaneous van der Waals potential over the time scale corresponding to the round-trip travel time of light between atom and surface. We show that the non-local phase contributions are non-additive, and propose to use this property in a multiple-path van der Waals interferometer in order to isolate them from the standard (and much larger) quasi-static van der Waals phase.

  1. Suspension of atoms and gravimetry using a pulsed standing wave

    CERN Document Server

    Hughes, K J; Sackett, C A

    2009-01-01

    Atoms from an otherwise unconfined 87Rb condensate are shown to be suspended against gravity using repeated reflections from a pulsed optical standing wave. Reflection efficiency was optimized using a triple-pulse sequence that, theoretically, provides accuracies better than 99.9%. Experimentally, up to 100 reflections are observed, leading to dynamical suspension for over 100 ms. The velocity sensitivity of the reflections can be used to determine the local gravitational acceleration. Further, a gravitationally sensitive atom interferometer was implemented using the suspended atoms, with packet coherence maintained for a similar time. These techniques could be useful for the precise measurement of gravity when it is impractical to allow atoms to fall freely over a large distance.

  2. Atom gyroscope with disordered arrays of quantum rings

    Energy Technology Data Exchange (ETDEWEB)

    Dayon, Daniel J; Toland, John R E; Search, Chris P, E-mail: csearch@stevens.ed [Department of Physics and Engineering Physics, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)

    2010-06-14

    Atom interferometry is of considerable interest in part because of the ability to interferometrically detect inertial rotations via the Sagnac effect with a potential sensitivity 10{sup 10} greater than optical gyroscopes. It has been shown recently that a coherently coupled array of identical interferometers can significantly enhance the sensitivity to rotations due to the appearance of transmission bands as a function of the inertial rotation rate {Omega}. Here we consider phase coherent transport of atomic matter waves in a chain of ring interferometers with a single occupied transverse mode in the presence of a rotation, {Omega}, and study the effect of variations in the size of the rings. We show that for randomly sized rings, the entire array functions as a highly sensitive Sagnac interferometer provided the level of random size fluctuations does not exceed a few per cent of the mean size. We also analyse how the use of individual defect states and controlled variations of the sizes in the array can be used to further enhance the sensitivity by creating narrow transmission resonances inside of a zero transmission gap.

  3. Atom Skimmers and Atom Lasers Utilizing Them

    Science.gov (United States)

    Hulet, Randall; Tollett, Jeff; Franke, Kurt; Moss, Steve; Sackett, Charles; Gerton, Jordan; Ghaffari, Bita; McAlexander, W.; Strecker, K.; Homan, D.

    2005-01-01

    Atom skimmers are devices that act as low-pass velocity filters for atoms in thermal atomic beams. An atom skimmer operating in conjunction with a suitable thermal atomic-beam source (e.g., an oven in which cesium is heated) can serve as a source of slow atoms for a magneto-optical trap or other apparatus in an atomic-physics experiment. Phenomena that are studied in such apparatuses include Bose-Einstein condensation of atomic gases, spectra of trapped atoms, and collisions of slowly moving atoms. An atom skimmer includes a curved, low-thermal-conduction tube that leads from the outlet of a thermal atomic-beam source to the inlet of a magneto-optical trap or other device in which the selected low-velocity atoms are to be used. Permanent rare-earth magnets are placed around the tube in a yoke of high-magnetic-permeability material to establish a quadrupole or octupole magnetic field leading from the source to the trap. The atoms are attracted to the locus of minimum magnetic-field intensity in the middle of the tube, and the gradient of the magnetic field provides centripetal force that guides the atoms around the curve along the axis of the tube. The threshold velocity for guiding is dictated by the gradient of the magnetic field and the radius of curvature of the tube. Atoms moving at lesser velocities are successfully guided; faster atoms strike the tube wall and are lost from the beam.

  4. Biprism Electron Interferometry with a Single Atom Tip Source

    CERN Document Server

    Schütz, Georg; Pooch, Andreas; Meier, Simon; Schneeweiss, Philipp; Rauschenbeutel, Arno; Günther, Andreas; Chang, Wei-Tse; Hwang, Ing-Shouh; Stibor, Alexander

    2013-01-01

    Experiments with electron or ion matter waves require a coherent, monochromatic and long-term stable source with high brightness. These requirements are best fulfilled by single atom tip (SAT) field emitters. The performance of an iridium covered W(111) SAT is demonstrated and analyzed for electrons in a biprism interferometer. Furthermore we characterize the emission of the SAT in a separate field electron and field ion microscope and compare it with other emitter types. A new method is presented to fabricate the electrostatic charged biprism wire that separates and combines the matter wave. In contrast to other biprism interferometers the source and the biprism size are well defined within a few nanometers. The setup has direct applications in ion interferometry and Aharonov-Bohm physics.

  5. A microwave interferometer for small and tenuous plasma density measurements.

    Science.gov (United States)

    Tudisco, O; Lucca Fabris, A; Falcetta, C; Accatino, L; De Angelis, R; Manente, M; Ferri, F; Florean, M; Neri, C; Mazzotta, C; Pavarin, D; Pollastrone, F; Rocchi, G; Selmo, A; Tasinato, L; Trezzolani, F; Tuccillo, A A

    2013-03-01

    The non-intrusive density measurement of the thin plasma produced by a mini-helicon space thruster (HPH.com project) is a challenge, due to the broad density range (between 10(16) m(-3) and 10(19) m(-3)) and the small size of the plasma source (2 cm of diameter). A microwave interferometer has been developed for this purpose. Due to the small size of plasma, the probing beam wavelength must be small (λ = 4 mm), thus a very high sensitivity interferometer is required in order to observe the lower density values. A low noise digital phase detector with a phase noise of 0.02° has been used, corresponding to a density of 0.5 × 10(16) m(-3).

  6. A microwave interferometer for small and tenuous plasma density measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tudisco, O.; Falcetta, C.; De Angelis, R.; Florean, M.; Neri, C.; Mazzotta, C.; Pollastrone, F.; Rocchi, G.; Tuccillo, A. A. [ENEA CR Frascati, Via E. Fermi 45, 00044 Frascati (Italy); Lucca Fabris, A.; Manente, M.; Ferri, F.; Tasinato, L.; Trezzolani, F. [CISAS ' G.Colombo,' Universita degli studi di Padova, Via Venezia 15, 35131 Padova (Italy); Accatino, L. [ACC Antenna and MW tech, Via Trieste 16/B, 10098 Rivoli (Italy); Pavarin, D. [Dip. di Ingegneria Industriale (DII), Universita degli Studi di Padova, Via Venezia 1, 35131 Padova (Italy); Selmo, A. [RESIA, Studio Progettazione e Realizzazione di Apparati Elettronici, via Roma 17, 37041 Albaredo d' Adige (Italy)

    2013-03-15

    The non-intrusive density measurement of the thin plasma produced by a mini-helicon space thruster (HPH.com project) is a challenge, due to the broad density range (between 10{sup 16} m{sup -3} and 10{sup 19} m{sup -3}) and the small size of the plasma source (2 cm of diameter). A microwave interferometer has been developed for this purpose. Due to the small size of plasma, the probing beam wavelength must be small ({lambda}= 4 mm), thus a very high sensitivity interferometer is required in order to observe the lower density values. A low noise digital phase detector with a phase noise of 0.02 Degree-Sign has been used, corresponding to a density of 0.5 Multiplication-Sign 10{sup 16} m{sup -3}.

  7. Fourier transform spectrometer based on Fabry-Perot interferometer.

    Science.gov (United States)

    Al-Saeed, Tarek A; Khalil, Diaa A

    2016-07-10

    We analyze the Fourier transform spectrometer based on a symmetric/asymmetric Fabry-Perot interferometer. In this spectrometer, the interferogram is obtained by recording the intensity as a function of the interferometer length. Then, we recover the spectrum by applying the discrete Fourier transform (DFT) directly on the interferogram. This technique results in spectral harmonic overlap and fictitious wavenumber components outside the original spectral range. For this purpose, in this work, we propose a second method to recover the spectrum. This method is based on expanding the DFT of the interferogram and the spectrum by a Haar or box function. By this second method, we recovered the spectrum and got rid of the fictitious spectral components and spectral harmonic overlap.

  8. Angular vibration measurement using grating and laser interferometer

    Science.gov (United States)

    Zhang, Li; Peng, Jun

    2006-06-01

    Primary angular acceleration calibration standard is developed by CIMM to generate standard rotational angle, angular velocity and angular acceleration, which are traceable to the International System of Units (SI). It can be used to calibrate angular transducers, i.e. angular accelerometer, angular velocity transducer, and rotational angle transducer to obtain amplitude sensitivity and phase shift by sinusoidal vibration. The measurement systems based on grating and laser interferometers are introduced in this paper. The measurement system based on PXI bus instrument is used to control the angular exciter, measure the output signal of the laser interferometers and the transducer to be calibrated synchronously. The methods for calculating the amplitude and phase of sinusoidal angular movement are investigated and high performance has been achieved. It shows the standard can be used in angular movement calibration in the frequency range from 0.1Hz to 200Hz.

  9. The Michelson interferometer-how to detect invisible interference patterns

    Energy Technology Data Exchange (ETDEWEB)

    Verovnik, Ivo [National Education Institute of Slovenia, Ljubljana, Slovenia (Slovenia); Likar, Andrej [Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana (Slovenia)

    2004-11-12

    In a Michelson interferometer, the contrast of the interference pattern fades away due to incoherence of light when the mirrors are not in equidistant positions. We propose an experiment where the distance between the interference fringes can be determined, even when the difference in length of the interferometer arms is far beyond the coherence length of the light, i.e. when the interference pattern disappears completely for the naked eye. We used a semiconductor laser with two photodiodes as sensors, which enabled us to follow the fluctuations of the light intensity on the screen. The distance between invisible interference fringes was determined from periodic changes of the summed fluctuating signal, obtained by changing the distance between the two sensors.

  10. Spectropolarimetric interferometer based on single-mode glass waveguides.

    Science.gov (United States)

    Qi, Zhi-Mei; Xia, Shanhong; Matsuda, Naoki

    2008-02-04

    A novel simple spectropolarimetric interferometer was developed based on single-mode potassium ion-exchanged (PIE) glass waveguides that generally have a large birefringence due to the compressive stress induced in the ion-exchanged layers. By using the spectropolarimetric interferometry, wavelength dependence of the modal birefringence of single-mode PIE waveguides was accurately obtained in a broad bandwidth, without need to measure individual modal indices. The modal birefringence decreases with increasing wavelength. The spectropolarimetric interferometer was demonstrated to be responsive to changes occurring within the penetration depth of the evanescent field. A refractive-index change of Deltan = 0.002 was easily detected in the case of a 2-cm-long interaction path length.

  11. Limiting the effects of earthquakes on gravitational-wave interferometers

    CERN Document Server

    Coughlin, Michael; Harms, Jan; Biscans, Sebastien; Buchanan, Christopher; Coughlin, Eric; Donovan, Fred; Fee, Jeremy; Gabbard, Hunter; Guy, Michelle; Mukund, Nikhil; Perry, Matthew

    2016-01-01

    Ground-based gravitational wave interferometers such as the Laser Interferometer Gravitational-wave Observatory (LIGO) are susceptible to high-magnitude teleseismic events, which can interrupt their operation in science mode and significantly reduce the duty cycle. It can take several hours for a detector to stabilize enough to return to its nominal state for scientific observations. The down time can be reduced if advance warning of impending shaking is received and the impact is suppressed in the isolation system with the goal of maintaining stable operation even at the expense of increased instrumental noise. Here we describe an early warning system for modern gravitational-wave observatories. The system relies on near real-time earthquake alerts provided by the U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA). Hypocenter and magnitude information is generally available in 5 to 20 minutes of a significant earthquake depending on its magnitude and location. The al...

  12. Detecting ultralight axion dark matter wind with laser interferometers

    CERN Document Server

    Aoki, Arata

    2016-01-01

    The ultralight axion with mass around $10^{-23}$ eV is known as a candidate of dark matter. A peculiar feature of the ultralight axion is oscillating pressure in time, which produces oscillation of gravitational potentials. Since the solar system moves through the dark matter halo at the velocity of about $v \\sim 300 \\, \\text{km} / \\text{s} = 10^{-3}$, there exists axion wind, which looks like scalar gravitational waves for us. Hence, there is a chance to detect ultralight axion dark matter with a wide mass range by using laser interferometer detectors. We calculate the detector signal induced by the oscillating pressure of the ultralight axion field, which would be detected by future laser interferometer experiments. We also argue that the detector signal can be enhanced due to the resonance in modified gravity theory explaining the dark energy.

  13. Density Measurement of Compact Toroid with Mach-Zehnder Interferometer

    Science.gov (United States)

    Laufman-Wollitzer, Lauren; Endrizzi, Doug; Brookhart, Matt; Flanagan, Ken; Forest, Cary

    2016-10-01

    Utilizing a magnetized coaxial plasma gun (MCPG) built by Tri Alpha Energy, a dense compact toroid (CT) is created and injected at high speed into the Wisconsin Plasma Astrophysics Laboratory (WiPAL) vessel. A modified Mach-Zehnder interferometer from the Line-Tied Reconnection Experiment (LTRX) provides an absolute measurement of electron density. The interferometer is located such that the beam intersects the plasma across the diameter of the MCPG drift region before the CT enters the vessel. This placement ensures that the measurement is taken before the CT expand. Results presented will be used to further analyze characteristics of the CT. Funding provided by DoE, NSF, and WISE Summer Research.

  14. The quantum bit from relativity of simultaneity on an interferometer

    CERN Document Server

    Garner, Andrew J P; Dahlsten, Oscar C O

    2014-01-01

    The patterns of fringes produced by an interferometer have always been important testbeds for our best contemporary theories of physics. Historically, interference has been used to contrast quantum mechanics to classical physics, but recently experiments have been performed that test quantum theory against even more exotic alternatives. A physically motivated family of theories are those where the state space of a two-level system is given by a sphere of arbitrary dimension. This includes classical bits, and real, complex and quaternionic quantum theory. In this paper, we consider relativity of simultaneity (that observers may disagree about the order of events at different locations) as applied to a two-armed interferometer. We show that this forbids most interference phenomena more complicated than those of standard complex quantum theory. In this sense, special relativity itself can be used to explain why physics should be described by the rules of quantum theory in this setup. Moreover, our result has con...

  15. Fiber-diffraction Interferometer using Coherent Fiber Optic Taper

    CERN Document Server

    Kihm, Hagyong

    2010-01-01

    We present a fiber-diffraction interferometer using a coherent fiber optic taper for optical testing in an uncontrolled environment. We use a coherent fiber optic taper and a single-mode fiber having thermally-expanded core. Part of the measurement wave coming from a test target is condensed through a fiber optic taper and spatially filtered from a single-mode fiber to be reference wave. Vibration of the cavity between the target and the interferometer probe is common to both reference and measurement waves, thus the interference fringe is stabilized in an optical way. Generation of the reference wave is stable even with the target movement. Focus shift of the input measurement wave is desensitized by a coherent fiber optic taper.

  16. Application of fiber interferometer in coherent Doppler lidar

    Institute of Scientific and Technical Information of China (English)

    Zongfeng Ma; Chunxi Zhang; Pan Ou; Guangming Luo; Zhaoyang Zhang

    2008-01-01

    @@ A novel coherent Doppler lidar (CDL) system based on single-mode fiber (SMF) components and instruments is presented to measure the speed of target. A fiber interferometer used in CDL system is reported.This fiber mixer is employed as a coherent receiver to resolve the shifts of signal-to-noise ratio (SNR) and mixing efficiency induced by backscattered field's wavefront error. For a certain wavelength, the maximum coupling efficiency between signal and SMF is determined by the ratio of pupil diameter to focal length of the coupling lens. The legible interference patterns and spectrum signals show that fiber interferometer is suitable to compensate for amplitude and phase vibrations. This robust coherent receiver can achieve improved CDL system performance with less transmitter power.

  17. Laser diode feedback interferometer for measurement of displacements without ambiguity

    Energy Technology Data Exchange (ETDEWEB)

    Donati, S.; Giuliani, G.; Merlo, S. [Univ. di Pavia (Italy). Dipt. di Elettronica

    1995-01-01

    The authors report what, to their knowledge, is the first example of laser feedback interferometer capable of measuring displacements of arbitrary form using a single interferometric channel. With a GaAlAs laser diode they can measure 1.2-m displacements, with interferometric resolution, simply by means of the backreflection from the surface (reflective or diffusive) under test. The operation is performed at moderate (i.e., not very weak) levels of feedback, such that a two-level hysteresis is found in the amplitude modulated signal. This is shown to allow the recovery of displacement without sign ambiguity from a single interferometric signal. Experimental results are reported, which are found to be in good agreement with the underlying theory. Performances of the developed feedback interferometer are finally presented.

  18. Laser exposure analysis for a near-infrared ocular interferometer

    Science.gov (United States)

    Primeau, Brian C.; Goldstein, Goldie L.; Greivenkamp, John E.

    2012-06-01

    Ocular interferometry has potential value in a variety of ocular measurement applications, including measuring ocular thicknesses, topography of ocular surfaces or the wavefront of the eye. Of particular interest is using interferometry for characterizing corneal shape and irregular corneal features, making this technology attractive due to its inherent accuracy and spatial resolution. A particular challenge of designing an ocular interferometer is determining safe laser exposure levels to the eye, including both the retina and anterior segment. Described here are the laser exposure standards relevant in the interferometer design and the corresponding calculations and results. The results of this work can be used to aid in the design of similar laser-based systems for ocular evaluation.

  19. Towards a FPGA-controlled deep phase modulation interferometer

    CERN Document Server

    Terán, M; Gesa, L l; Mateos, I; Gibert, F; Karnesis, N; Ramos-Castro, J; Schwarze, T S; Gerberding, O; Heinzel, G; Guzmán, F; Nofrarias, M

    2014-01-01

    Deep phase modulation interferometry was proposed as a method to enhance homodyne interferometers to work over many fringes. In this scheme, a sinusoidal phase modulation is applied in one arm while the demodulation takes place as a post-processing step. In this contribution we report on the development to implement this scheme in a fiber coupled interferometer controlled by means of a FPGA, which includes a LEON3 soft-core processor. The latter acts as a CPU and executes a custom made application to communicate with a host PC. In contrast to usual FPGA-based designs, this implementation allows a real-time fine tuning of the parameters involved in the setup, from the control to the post-processing parameters.

  20. Active multi-mode-interferometer broadband superluminescent diodes

    Science.gov (United States)

    Feifei, Wang; Peng, Jin; Ju, Wu; Yanhua, Wu; Fajie, Hu; Zhanguo, Wang

    2016-01-01

    We report a new quantum dot superluminescent diode with a new device structure. In this device, a multi-mode-interferometer configuration and a J-bend structure were monolithically integrated. Owing to the multi-mode-interferometer structure, the superluminescent diode exhibits 60% increase in output power and 43% reduction in the differential resistance compared with the uniform waveguide width superluminescent diode fabricated from the same wafer. Our device produces an emission spectrum as wide as 103.7 nm with an output power of 2.5 mW at 600 mA continue-wave injection current. This broadband emission spectrum makes the axial resolution of the optical coherence tomography system employing the superluminescent diode to 6 μm in theory, which is high enough for most tissue imaging. Project supported by the National Natural Science Foundation of China (No. 61274072) and the National High Technology Research and Development Program of China (No. 2013AA014201).

  1. Optical displacement measurement using a monolithic Michelson interferometer

    Science.gov (United States)

    Hofstetter, Daniel; Zappe, Hans P.

    1997-04-01

    Contactless optical displacement measurement has the potential for a variety of industrial and scientific applications. For highly accurate displacement measurements at distances below 1 m, interferometric methods are preferred over most other methods. This is mainly because of the good resolution and the possibility of doing the measurements in real-time. Furthermore, the use of direct bandgap semiconductor materials also enables the fabrication of a compact interferometer-based device which unites all necessary components, including the light emitter, on a single chip. In this paper, a monolithically integrated optical displacement sensor fabricated in the GaAs/AlGaAs material system is reported. This single chip microsystem is configured as a double Michelson interferometer and comprises a distributed Bragg reflector laser, photodetectors, phase shifters and waveguide couplers. In the course of this paper, we will also briefly discuss possible scientific and industrial applications of such devices.

  2. Multi-object fixed delay Michelson interferometer for astronomical observation

    Science.gov (United States)

    Zhang, Kai; Zhu, Yongtian; Wang, Lei; Chen, Yi; Wang, Liang

    2012-10-01

    Optical interferometry isn't only widely applied into optical workshop, but also makes great contribution in astronomical observation. A multi-object fixed delay Michelson interferometer commissioned to search extra-solar planet (exoplanet) is introduced here. Fixed delay of 1.9mm, which is good for stellar radial velocity measuring precision, is obtained by two interference arms with different materials. This configuration has different refractive indexes and physical characteristics so that supplies wider field of view and better thermal stability. In addition, compact interference component with three glued prisms and smart structure are the other important features. Because of vibration influence, the combination among the prisms is a direct and effective method. And the reason why make the structure as small as possible is of central obscuration under the workspace of interferometer.

  3. Comb-referenced laser distance interferometer for industrial nanotechnology

    Science.gov (United States)

    Jang, Yoon-Soo; Wang, Guochao; Hyun, Sangwon; Kang, Hyun Jay; Chun, Byung Jae; Kim, Young-Jin; Kim, Seung-Woo

    2016-08-01

    A prototype laser distance interferometer is demonstrated by incorporating the frequency comb of a femtosecond laser for mass-production of optoelectronic devices such as flat panel displays and solar cell devices. This comb-referenced interferometer uses four different wavelengths simultaneously to enable absolute distance measurement with the capability of comprehensive evaluation of the measurement stability and uncertainty. The measurement result reveals that the stability reaches 3.4 nm for a 3.8 m distance at 1.0 s averaging, which further reduces to 0.57 nm at 100 s averaging with a fractional stability of 1.5 × 10-10. The uncertainty is estimated to be in a 10-8 level when distance is measured in air due to the inevitable ambiguity in estimating the refractive index, but it can be enhanced to a 10-10 level in vacuum.

  4. Optical microfiber mode interferometer for temperature-independent refractometric sensing.

    Science.gov (United States)

    Salceda-Delgado, G; Monzon-Hernandez, D; Martinez-Rios, A; Cardenas-Sevilla, G A; Villatoro, J

    2012-06-01

    We report on a functional optical microfiber mode interferometer and its applications for absolute, temperature-insensitive refractive index sensing. A standard optical fiber was tapered down to 10 μm. The central part of the taper, i.e., the microfiber, is connected to the untapered regions with two identical abrupt transitions. The transmission spectrum of our device exhibited a sinusoidal pattern due to the beating between modes. In our interferometer the period of the pattern-an absolute parameter-depends strongly on the surrounding refractive index but it is insensitive to temperature changes. The period, hence the external index, can be accurately measured by taking the fast Fourier transform (FFT) of the detected interference pattern. The measuring refractive index range of the device here proposed goes from 1.33 to 1.428 and the maximum resolution is on the order of 3.7×10(-6).

  5. Quantum interference in an asymmetric Mach-Zehnder interferometer

    Science.gov (United States)

    Trenti, A.; Borghi, M.; Mancinelli, M.; Price, H. M.; Fontana, G.; Pavesi, L.

    2016-08-01

    A re-visitation of the well known free space Mach-Zehnder interferometer is reported here. The coexistence between one-photon and two-photons interference from collinear color entangled photon pairs is investigated. Thisarises from an arbitrarily small unbalance in the arm transmittance. The tuning of such asymmetry is reflected in dramatic changes in the coincidence detection, revealing beatings between one particle and two particle interference patterns. In particular, the role of the losses and of the intrinsic phase imperfectness of the lossy beamsplitter are explored in a single-port excited Mach-Zehnder interferometer. This configuration is especially useful for quantum optics on a chip, where the guiding geometry forces photons to travel in the same spatial mode.

  6. Spatial heterodyne spectrometer based on the Mach-Zehnder interferometer

    Science.gov (United States)

    Cai, Qisheng; Xiangli, Bin; Du, Shusong

    2015-11-01

    Spatial heterodyne spectroscopy (SHS) is a new kind of Fourier-transform spectroscopic technique capable of very high spectral resolution. In this paper, a spatial heterodyne spectrometer based on the Mach-Zehnder interferometer (MZ-SHS) is proposed. It is modified by replacing one mirror in the Mach-Zehnder interferometer with a diffraction grating. This technique retains many of the advantages of traditional SHS. Moreover, the spatial frequency of the interferogram is strictly linear with wavenumber. We describe the concept of the new MZ-SHS and elaborate the exact expression of the interferogram. Also, a design example and two kinds of imitated interferograms are presented in this paper. One is simulated in MATLAB and the other is generated in ZEMAX using ray tracing method. The retrieved spectra from these two interferograms show a good agreement with the theoretical results.

  7. Orbit analysis of a geostationary gravitational wave interferometer detector array

    CERN Document Server

    Tinto, Massimo; Kuga, Helio K; Alves, Marcio E S; Aguiar, Odylio D

    2014-01-01

    We analyze the trajectories of three geostationary satellites forming the GEOstationary GRAvitational Wave Interferometer (GEOGRAWI)~\\cite{tinto}, a space-based laser interferometer mission aiming to detect and study gravitational radiation in the ($10^{-4} - 10$) Hz band. The combined effects of the gravity fields of the Earth, the Sun and the Moon make the three satellites deviate from their nominally stationary, equatorial and equilateral configuration. Since changes in the satellites relative distances and orientations could negatively affect the precision of the laser heterodyne measurements, we have derived the time-dependence of the inter-satellite distances and velocities, the variations of the polar angles made by the constellation's three arms with respect to a chosen reference frame, and the time changes of the triangle's enclosed angles. We find that, during the time between two consecutive station-keeping maneuvers (about two weeks), the relative variations of the inter-satellite distances do not...

  8. Balanced polarization maintaining fiber Sagnac interferometer vibration sensor.

    Science.gov (United States)

    Wada, Kenji; Narui, Hirokazu; Yamamoto, Daiki; Matsuyama, Tetsuya; Horinaka, Hiromichi

    2011-10-24

    To achieve a nearly zero-delay operating point in a polarization-maintaining (PM) fiber Sagnac interferometer, two identical PM fibers were incorporated so that their two main axes were orthogonally coupled to each other. A simple fiber vibration sensor system was constructed with a light emitting diode and a balanced PM fiber Sagnac interferometer, in which one of the PM fibers was used as a sensing cable and the other as a reference cable. The vibration sensor was confirmed to be temperature-compensated and generated a phase shift per unit length and unit strain of the sensor of 4.7 milliradian/(m·με) when mechanical vibrations with 1 kHz sinusoidal and triangular waves were stably observed under an input power of 10 μW.

  9. Atom interferometry in space: thermal management and magnetic shielding.

    Science.gov (United States)

    Milke, Alexander; Kubelka-Lange, André; Gürlebeck, Norman; Rievers, Benny; Herrmann, Sven; Schuldt, Thilo; Braxmaier, Claus

    2014-08-01

    Atom interferometry is an exciting tool to probe fundamental physics. It is considered especially apt to test the universality of free fall by using two different sorts of atoms. The increasing sensitivity required for this kind of experiment sets severe requirements on its environments, instrument control, and systematic effects. This can partially be mitigated by going to space as was proposed, for example, in the Spacetime Explorer and Quantum Equivalence Principle Space Test (STE-QUEST) mission. However, the requirements on the instrument are still very challenging. For example, the specifications of the STE-QUEST mission imply that the Feshbach coils of the atom interferometer are allowed to change their radius only by about 260 nm or 2.6 × 10(-4) % due to thermal expansion although they consume an average power of 22 W. Also Earth's magnetic field has to be suppressed by a factor of 10(5). We show in this article that with the right design such thermal and magnetic requirements can indeed be met and that these are not an impediment for the exciting physics possible with atom interferometers in space.

  10. Atom interferometry in space: Thermal management and magnetic shielding

    Energy Technology Data Exchange (ETDEWEB)

    Milke, Alexander; Kubelka-Lange, André; Gürlebeck, Norman, E-mail: norman.guerlebeck@zarm.uni-bremen.de; Rievers, Benny; Herrmann, Sven [Center of Applied Space Technology and Microgravity (ZARM), University Bremen, Am Fallturm, 28359 Bremen (Germany); Schuldt, Thilo [DLR Institute for Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany); Braxmaier, Claus [Center of Applied Space Technology and Microgravity (ZARM), University Bremen, Am Fallturm, 28359 Bremen (Germany); DLR Institute for Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany)

    2014-08-15

    Atom interferometry is an exciting tool to probe fundamental physics. It is considered especially apt to test the universality of free fall by using two different sorts of atoms. The increasing sensitivity required for this kind of experiment sets severe requirements on its environments, instrument control, and systematic effects. This can partially be mitigated by going to space as was proposed, for example, in the Spacetime Explorer and Quantum Equivalence Principle Space Test (STE-QUEST) mission. However, the requirements on the instrument are still very challenging. For example, the specifications of the STE-QUEST mission imply that the Feshbach coils of the atom interferometer are allowed to change their radius only by about 260 nm or 2.6 × 10{sup −4} % due to thermal expansion although they consume an average power of 22 W. Also Earth's magnetic field has to be suppressed by a factor of 10{sup 5}. We show in this article that with the right design such thermal and magnetic requirements can indeed be met and that these are not an impediment for the exciting physics possible with atom interferometers in space.

  11. Possible Approach to Improve Sensitivity of a Michelson Interferometer

    Institute of Scientific and Technical Information of China (English)

    FU Jian; TANG Shao-Fang

    2007-01-01

    @@ We propose a possible approach to achieve a 1/N sensitivity of Michelson interferometer by using a properly designed random phase modulation. Different from other approaches, the sensitivity improvement does not depend on increasing optical powers or utilizing the quantum properties of light. Moreover the requirements for optical losses and the quantum efficiencies of photodetection systems may be lower than the quantum approaches and the sensitivity improvement is independent of frequency in all the detection bands.

  12. Dissipative Optomechanics in a Michelson--Sagnac Interferometer

    OpenAIRE

    Xuereb, A.; Schnabel, R.; Hammerer, K.

    2011-01-01

    Dissipative optomechanics studies the coupling of the motion of an optical element to the decay rate of a cavity. We propose and theoretically explore a realization of this system in the optical domain, using a combined Michelson--Sagnac interferometer, which enables a strong and tunable dissipative coupling. Quantum interference in such a setup results in the suppression of the lower motional sideband, leading to strongly enhanced cooling in the non-sideband-resolved regime. With state-of-th...

  13. Michelson interferometer null may confirm transverse Doppler Effect

    CERN Document Server

    Woodruff, Robert A

    2014-01-01

    We analyze fringe formation within Michelson-like experiments as viewed by relativistic inertial observers. Our analysis differs from previous work because we include optical misalignment of the beamsplitter of the interferometer due to the anamorphic geometry of relativistic Lorentz contraction. We conclude that inertial frame equivalence of Michelson-like experiments provide verification of the transverse Doppler Effect and exclude any model incorporating the relativistic Lorentz contraction effect.

  14. Infrared spectra of lunar soils. [using a Michelson interferometer

    Science.gov (United States)

    Aronson, J. R.; Emslie, A. G.; Smith, E. M.

    1979-01-01

    Measured data obtained by Michelson interferometer spectrometer were stored in a computer file and smoothed by being passed forward and backward through a digital four-pole low pass filter. Infrared spectra of the 10 lunar samples are presented in the format of brightness temperature versus frequency. The mol % of feldspar, pyroxene, olivine, ilmenite and ferromagnetic silicate in each sample is presented in tables. The reflectance spectra of ilmenite and enstatite are shown in graphs.

  15. Realization of an Ultrasensitive Heisenberg-Limited Interferometer

    Science.gov (United States)

    2006-07-31

    used a Monte Carlo simulation program to examine the effect of losses on this highly nonlinear detection scheme, with its experimental imple...is below since many authors do not follow the 200 word limit 14. SUBJECT TERMS quantum optics, nonlinear optics, squeezed states, Heisenberg -limited...Programs 1001 N. Emmett St. P.O. Box 400195 Charlottesville, VA 22904 -4195 Realization of an Ultrasensitive Heisenberg -Limited Interferometer REPORT

  16. Fiber inline Michelson interferometer fabricated by a femtosecond laser.

    Science.gov (United States)

    Yuan, Lei; Wei, Tao; Han, Qun; Wang, Hanzheng; Huang, Jie; Jiang, Lan; Xiao, Hai

    2012-11-01

    A fiber inline Michelson interferometer was fabricated by micromachining a step structure at the tip of a single-mode optical fiber using a femtosecond laser. The step structure splits the fiber core into two reflection paths and produces an interference signal. A fringe visibility of 18 dB was achieved. Temperature sensing up to 1000°C was demonstrated using the fabricated assembly-free device.

  17. All-fiber interferometer for chromatic dispersion measurements

    OpenAIRE

    Thévenaz, Luc; Pellaux, J. P.; Von der Weid, J. P.

    1988-01-01

    An all-fiber interferometric method for chromatic dispersion measurements in meter-length single-mode fibers is presented. In a Michelson setup the physical length of a reference fiber was varied so as to obtain adjustable optical delay. Time resolution, ease of manipulation, and mechanical isolation are considerably improved with respect to conventional interferometers. Resolution of group delay measurement and chromatic dispersion over the full 1100-1700-nm spectral range are better than 5 ...

  18. Detection of falsification of security documents using white light interferometer

    OpenAIRE

    Sugawara, Shigeru; Nakanishi, Shoichi; Itoh, Masahide; Yatagai, Toyohiko

    2010-01-01

    In order to verify the authenticity of security documents, we propose the measurement of the surface distortion of the cover film of security documents. Surface shapes of films of 31 genuine documents and 29 counterfeit documents were measured by using a white light interferometer. Differences between the surface features of a genuine security document and those of a counterfeit one were studied. Roughness and peak–valley density were the two features used to characterize the measured surface...

  19. Phase correction for a Michelson interferometer with misaligned mirrors

    Science.gov (United States)

    Goorvitch, D.

    1975-01-01

    The phase correction for a Michelson interferometer with misaligned mirrors in converging light is shown to give rise to a quadratic phase shift. In general, the calculation of a spectrum from the measured interferogram needs phase correction. Phase corrections have been well worked out for the cases of a linear phase shift and a phase that is slowly varying. The standard procedures for correcting calculated spectra need to be modified, however, to remove any phase errors resulting from misaligned mirrors.

  20. Evolved Stars: Interferometer Baby Food or Staple Diet?

    Science.gov (United States)

    Tuthill, Peter

    With their extreme red and infrared luminosities and large apparent diameters, evolved stars have nurtured generations of interferometers (beginning with Michelson's work on Betelgeuse) with unique science programs at attainable resolutions. Furthermore, the inflated photosphere and circumstellar material associated with dying stars presents complex targets with asymmetric structure on many scales encoding a wealth of poorly-understood astrophysics. A brief review the major past milestones and future prospects for interferometry's contribution to studies of circumstellar matter in evolved stars is presented.