A5085150918- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Advanced Frequency and Time Standards
- Scientific Measurement and Uncertainty Evaluation
- Quantum optics and atomic interactions
- Advanced Fiber Laser Technologies
- Advanced Measurement and Metrology Techniques
- Mechanical and Optical Resonators
- Solid State Laser Technologies
- Force Microscopy Techniques and Applications
- Atomic and Molecular Physics
- Semiconductor Lasers and Optical Devices
- Geophysics and Sensor Technology
- Laser Design and Applications
- Chemical Thermodynamics and Molecular Structure
- Spectroscopy and Laser Applications
- Particle accelerators and beam dynamics
- Dark Matter and Cosmic Phenomena
- Astro and Planetary Science
- Magnetic confinement fusion research
- Optical Polarization and Ellipsometry
- Digital Filter Design and Implementation
- Hemoglobin structure and function
- Quantum and Classical Electrodynamics
- Superconducting Materials and Applications
York University
2011-2024
Fluidigm (Canada)
2017
Slow antihydrogen ($\overline{\mathrm{H}}$) is produced within a Penning trap that located quadrupole Ioffe trap, the latter intended to ultimately confine extremely cold, ground-state $\overline{\mathrm{H}}$ atoms. Observed atoms in this configuration resolve debate about whether positrons and antiprotons can be brought together form divergent magnetic fields of trap. The number detected actually increases when 400 mK turned on.
We investigate channeling oscillations in the contrast of a density grating formed by exposing sample ultracold atoms to an optical standing-wave pulse. show that these dynamics can be imprinted on echo signal associated with two-pulse atom interferometer. Experimental results are supported simple model, which describes as combination two separate physical effects, namely, matter-wave interference and classical resulting Pendell\"osung-like oscillations. discuss enhancement strength...
We demonstrate the performance of a novel LA-ICP-MS system using metal-doped PMMA film.
We describe progress toward a precise measurement of the recoil energy an atom measured using perturbative grating-echo interferometer (AI) that involves three standing-wave (sw) pulses. With this technique, perturbing sw pulse is used to shift phase excited momentum states---producing modulation in contrast interference pattern. The signal exhibits narrow fringes revive periodically at twice two-photon frequency, $2\omega_q$, as function onset time pulse. Experiments are performed samples...
We demonstrate the performance characteristics of a new class vacuum-sealed, autolocking diode laser systems and their applications to precision metrology. The is based on adaptations design that uses optical feedback from an interference filter it includes vacuum-sealed cavity, interchangeable base-plate, digital controller. A change base-plate allows operation at desired wavelengths in visible near infrared spectral range, whereas ability be tuned frequency stabilized with respect atomic,...
Echo atom interferometers have emerged as interesting alternatives to Raman for the realization of precise measurements gravitational acceleration $g$ and determination atomic fine structure through recoil frequency $\omega_q$. Here we review development different configurations echo that are best suited achieve these goals. We describe experiments utilize near-resonant excitation laser-cooled rubidium atoms by a sequence standing wave pulses measure $\omega_q$ with statistical uncertainty...
We investigate the characteristics of near resonant Bragg scattering, underlying process that produces a signal in grating-echo atom interferometer. explore how density modulation produced an atomic sample by momentum state interference and optical channeling can be optimally read out using coherently Bragg-scattered traveling-wave electric field. When both scattering processes are optimized, we report 20-fold increase efficiency. Our results suggest quantitative understanding confinement...
We have developed two configurations of an echo interferometer that rely on standing wave excitation a laser-cooled sample rubidium atoms measures acceleration. For two-pulse configuration, the signal is modulated at recoil frequency and exhibits sinusoidal chirp as function pulse spacing. three-pulse stimulated observed without modulation single frequency. The configuration less sensitive to effects vibrations magnetic field curvature leading longer experimental timescale. both atom (AI),...
We describe a compact waveguide amplifier system that is suitable for optically pumping rubidium magnetometers. The consists of an auto-locking vacuum-sealed external cavity diode laser, semiconductor tapered and pulsing unit based on acousto-optic modulator. laser utilises optical feedback from interference filter to narrow the linewidth inexpensive ~500 kHz. This output scannable over 8 GHz range (at 780 nm) can be locked without human intervention any spectral marker in expandable library...
We describe a diode laser system for precision metrology that relies on adaptations of well-known design based optical feedback from an interference filter. The head operates with interchangeable base-plate, which allows single-mode performance at distinct wavelengths 633 nm and 780 nm. Frequency drifts are effectively suppressed by using vacuum-sealed head, thereby allowing the frequency to be stabilized time-scales several hours. Using digital auto-lock controller, we show can respect...
We present a unique external cavity diode laser system that can be auto-locked with reference to atomic and molecular spectra. The vacuum-sealed head design uses an interchangeable base-plate comprised of optical elements selected for desired wavelength ranges. feedback light the is provided by narrow-band interference filter, which tuned from outside fineadjust output in vacuum. To stabilize frequency, digital controller relies either on pattern-matching algorithm stored memory, or first...
We describe a simple time-of-flight technique for measuring the magnetic moment of an optically pumped magneto-optical trap. The relies on free-expansion imaging cold atom cloud in small field gradient without need to detect spatial separation between sublevels. find that effective acceleration can be used characterize extreme state optical pumping. In general case, we show integrated displacement falling accurately modeled using rate equation simulations sublevel populations, and knowledge...
Precision measurements of gravitational acceleration g have far reaching applications in navigation and sensing as well for tests general relativity. Grating-echo atom interferometers (AIs) utilize simple setups distinctive excitation schemes that involve a single laser, do not require velocity selection. They demonstrated gravity precise to 75 parts per billion (ppb) by dropping laser-cooled atomic samples through ~ 1 cm. Here we describe progress toward realizing cold gravimeter using an...
Abstract Antihydrogen (Hbar) was first produced at CERN in 1996. Over the past decade our ATRAP collaboration has made massive progress toward goal of producing large numbers cold Hbar atoms that will be captured a magnetic gradient trap for precise comparison between atomic spectra matter and antimatter. The AD provides bunches 3 × 10 7 low energy Pbars every 100 seconds. We capture cool to 4 K, 0.1% these cryogenic Penning trap. By stacking many we are able do experiments with 5 Pbars....
We have developed a versatile pulsed laser system for high precision magnetometry. The operating wavelength of the can be configured to optically pump alkali vapors such as rubidium and cesium. consists an auto-locked, interference filter stabilized, external cavity diode (ECDL), tapered waveguide amplifier, pulsing module. auto-locking controller used by untrained operator stabilize frequency with respect library atomic, molecular, solid-state spectral markers. ECDL output amplified from 20...
We explore the sensitivity of photon echo technique for achieving precise measurements atomic lifetimes. Using short-pulse excitation rubidium vapor, we report most statistically measurement ($26.11\ifmmode\pm\else\textpm\fi{}0.03$) ns $5^{2}{P}_{3/2}$ lifetime. This statistical uncertainty 0.11% was achieved in a total data acquisition time 4 h over several weeks and rivals this system. The experiment primarily relies on heterodyne detection exploits signal-to-noise ratio coherent release...
ATRAP has made many important improvements since CERN's Antiproton Decelerator (AD) was restarted in 2006. These include substantial increases the number of positrons (e+) and antiprotons (Pbars) used to make antihydrogen (Hbar) atoms, a new technique for loading electrons (e−) that are cool Pbars e+, implementation completely new, larger more robust apparatus our second experimental zone inclusion quadrupole Ioffe trap intended coldest Hbar atoms produced. Using this we have produced large...
We characterize a new class of vacuum-sealed, auto-locked diode lasers through the Allan deviation beat note and lock signal demonstrate applications relevant to industrial gravimetry lidar transmission.
We discuss progress towards a precision measurement of the atomic recoil frequency in <sup>85</sup>Rb using an echo-type atom interferometer. report single ~ 300 ppb on timescale 50 ms.
We discuss progress toward a precise measurement of the atomic recoil frequency using grating-echo atom interferometer and non-magnetic apparatus that permits signal lifetimes approaching transit time limit.