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Articles 31 - 33 of 33

Full-Text Articles in Atomic, Molecular and Optical Physics

Reflectivity Of A Cholesteric Liquid Crystal, Justin Lawson Jan 2010

Reflectivity Of A Cholesteric Liquid Crystal, Justin Lawson

Physics

In this paper we investigate the light properties of a chiral liquid crystal or a crystal for which the director angle relative to some fixed axis changes as a function of the crystal depth. Sometimes a dopant can introduce a chirality or "twist" in a nematic liquid crystal. For such cases of non-linear depth dependence (where chirality is determined by a diffusion equation) we may use this research to work backwards from a crystal's light properties to intensity and duration of dopant exposure.


Constructing A Magneto-Optical Trap For Cold Atom Trapping, Eric S. Muckley Dec 2009

Constructing A Magneto-Optical Trap For Cold Atom Trapping, Eric S. Muckley

Physics

A magneto-optical trap, or MOT, is a device that traps atoms between three pairs of opposing perpendicular laser beams for cooling the atoms to temperatures near absolute zero. The MOT uses Doppler cooling and a magnetic quadrupole field to trap the atoms; in our case, Rb87 atoms. In the future, the MOT will be used in experiments pertaining to the advancement of quantum computing. In this paper, I explain some of the processes required for construction and operation of the MOT.


Oscillator Strength Measurements Of The 5s6s 1s0→5snp 1p1 Rydberg Transitions Of Strontium, S. U. Haq, M. A. Kalyar, M. Rafiq, R. Ali, Naveed K. Piracha, M. A. Baig Apr 2009

Oscillator Strength Measurements Of The 5s6s 1s0→5snp 1p1 Rydberg Transitions Of Strontium, S. U. Haq, M. A. Kalyar, M. Rafiq, R. Ali, Naveed K. Piracha, M. A. Baig

Physics

We report the experimentally determined oscillator strengths for the 5s6s 1S0→5snp 1P1 Rydberg transitions of strontium using two-step excitation in conjunction with a thermionic diode ion detector. The absolute photoionization cross section from the 5s6s 1S0 excited state has been determined by adjusting the polarization vector of the ionizing laser beam parallel, perpendicular, and at the magic angle with respect to that of the exciting dye laser. The measured absolute value of the photoionization cross section 0.9±0.2 Mb at the 5s threshold is used to extract the f values of the 5s6s 1 …