Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
- File Type
Articles 1 - 10 of 10
Full-Text Articles in Physics
Absorption-Induced Trapping In An Anisotropic Magneto-Optical Trap, Joel A. Greenberg, M. Oria, Andrew M.C. Dawes, Daniel J. Gauthier
Absorption-Induced Trapping In An Anisotropic Magneto-Optical Trap, Joel A. Greenberg, M. Oria, Andrew M.C. Dawes, Daniel J. Gauthier
Andrew M C Dawes
We report on a simple anisotropic magneto-optical trap for neutral atoms that produces a large sample of cold atoms confined in a cylindrically-shaped volume with a high aspect ratio (100:1). Due to the large number of trapped atoms, the laser beams that propagate along the optically thick axis of the trap to cool the atoms are substantially attenuated. We demonstrate that the resulting intensity imbalance produces a net force that spatially localizes the atoms. This limits both the trap length and the total number of trapped atoms. Rotating the cooling beams by a small angle relative to the trap axis …
Distortion Management In Slow-Light Pulse Delay, Michael D. Stenner, Mark A. Neifeld, Zhaoming Zhu, Andrew M.C. Dawes, Daniel J. Gauthier
Distortion Management In Slow-Light Pulse Delay, Michael D. Stenner, Mark A. Neifeld, Zhaoming Zhu, Andrew M.C. Dawes, Daniel J. Gauthier
Andrew M C Dawes
We describe a methodology to maximize slow-light pulse delay subject to a constraint on the allowable pulse distortion. We show that optimizing over a larger number of physical variables can increase the distortion-constrained delay. We demonstrate these concepts by comparing the optimum slow-light pulse delay achievable using a single Lorentzian gain line with that achievable using a pair of closely-spaced gain lines. We predict that distortion management using a gain doublet can provide approximately a factor of 2 increase in slow-light pulse delay as compared with the optimum single-line delay. Experimental results employing Brillouin gain in optical fiber confirm our …
780 Nm Diode Lasers For Atomic Physics, Bryson Vivas, Simone Carpenter, Jenny Novak, Andrew M. C. Dawes
780 Nm Diode Lasers For Atomic Physics, Bryson Vivas, Simone Carpenter, Jenny Novak, Andrew M. C. Dawes
Andrew M C Dawes
This poster presents the results of the summer research project conducted by Bryson Vivas, Simone Carpenter, and Jenny Novak. The research was supervised by Dr. Andrew Dawes and conducted in the Photonics and Quantum Optics Lab of Pacific University.
Simultaneous Quantum-State Measurements Using Array Detection, Andrew Dawes, Mark Beck
Simultaneous Quantum-State Measurements Using Array Detection, Andrew Dawes, Mark Beck
Andrew M C Dawes
We have simultaneously measured the quantum states of two different spatial modes of the same optical beam by performing quantum-state tomography with an array detector. Both modes are well described by coherent states, but the projection of the signal onto the local oscillator mode contains a mean of 0.09 photons, while a more complicated mode has a mean of 4.3 photons. This demonstrates that for this particular mode the effective detection efficiency when using array detection is over 40 times greater than when using single detectors.
Direct Observation Of Optical Precursors In A Region Of Anomalous Dispersion, Heejeong Jeong, Andrew M.C. Dawes, Daniel J. Gauthier
Direct Observation Of Optical Precursors In A Region Of Anomalous Dispersion, Heejeong Jeong, Andrew M.C. Dawes, Daniel J. Gauthier
Andrew M C Dawes
We create optical precursors by propagating a step-modulated optical pulse through a linear resonant dielectric absorber. The field emerging from the dielectric consists of a several-nanosecond-long spike with near 100% transmission, which decays to a constant value expected from Beer’s law. This high transmission spike might be useful for imaging applications requiring penetrating optical radiation. We compare our observations to two different theories, revealing that the spike consists of both the Sommerfeld and Brillouin precursors.
All-Optical Switching With Transverse Optical Patterns, Andrew M.C. Dawes, Lucas Illing, Joel A. Greenberg, Daniel J. Gauthier
All-Optical Switching With Transverse Optical Patterns, Andrew M.C. Dawes, Lucas Illing, Joel A. Greenberg, Daniel J. Gauthier
Andrew M C Dawes
We demonstrate an all-optical switch that operates at ultra-low-light levels and exhibits several features necessary for use in optical switching networks. An input switching beam, wavelength λ, with an energy density of 10−2 photons per optical cross section [σ=λ2 / (2π)] changes the orientation of a two-spot pattern generated via parametric instability in warm rubidium vapor. The instability is induced with less than 1 mW of total pump power and generates several μWs of output light. The switch is cascadable: the device output is capable of driving multiple inputs, and exhibits transistor-like signal-level restoration with both saturated and intermediate response …
Using Transverse Optical Patterns For Ultra-Low-Light Optical Switching, Andrew M.C. Dawes
Using Transverse Optical Patterns For Ultra-Low-Light Optical Switching, Andrew M.C. Dawes
Andrew M C Dawes
All-optical devices allow improvements in the speed of optical communication and computation systems by avoiding the conversion between the optical and electronic domains. The focus of this thesis is the experimental investigation of a new type of all-optical switch that is based on the control of optical patterns formed by nonlinear interactions between light and matter. The all-optical switch consists of a pair of light beams that counterpropagate through warm rubidium vapor. These beams induce a nonlinear optical instability that gives rise to mirrorless parametric self-oscillation and generates light in the state of polarization that is orthogonal to that of …
Mode Optimization For Quantum-State Tomography With Array Detectors, Andrew M. Dawes, Mark Beck, K. Banaszek
Mode Optimization For Quantum-State Tomography With Array Detectors, Andrew M. Dawes, Mark Beck, K. Banaszek
Andrew M C Dawes
We demonstrate that it is possible to choose an optimal signal mode for state reconstruction when performing quantum-state tomography with array detectors. The mode optimization is done during the data analysis ~i.e., after all the data have been collected.! We develop theoretically a procedure for finding the mode that satisfies a criterion which is quadratic in field operators; as examples we explicitly show how to maximize the average photon number, or the amount of quadrature squeezing. We experimentally demonstrate the technique by finding the mode which maximizes the average photon number for coherent-state signal beams occupying both linear and sinusoidal …
Optical Switching With Cold Atoms, Andrew Dawes
Optical Switching With Cold Atoms, Andrew Dawes
Andrew M C Dawes
A Viewpoint on: Efficient All-Optical Switching Using Slow Light within a Hollow Fiber M. Bajcsy, S. Hofferberth, V. Balic, T. Peyronel, M. Hafezi, A. S. Zibrov, V. Vuletic, and M. D. Lukin Phys. Rev. Lett. 102, 203902 (2009) – Published May 18, 2009
Broadband Sbs Slow Light In An Optical Fiber, Zhaoming Zhu, Andrew M.C. Dawes, Daniel J. Gauthier, Lin Zhang, Alan E. Willner
Broadband Sbs Slow Light In An Optical Fiber, Zhaoming Zhu, Andrew M.C. Dawes, Daniel J. Gauthier, Lin Zhang, Alan E. Willner
Andrew M C Dawes
In this paper, we investigate slow light via stimulated Brillouin scattering (SBS) in a room temperature optical fiber that is pumped by a spectrally broadened laser. Broadening the spectrum of the pump field increases the linewidth Δωp of the Stokes amplifying resonance, thereby increasing the slow-light bandwidth. One physical bandwidth limitation occurs when the linewidth becomes several times larger than the Brillouin frequency shift ΩB so that the anti-Stokes absorbing resonance substantially cancels out the Stokes amplifying resonance and, hence, the slow-light effect. We find that partial overlap of the Stokes and anti-Stokes resonances can actually lead to an enhancement …