Journal of the Optical Society of America B, 18, 855, 2001
Measurement of the Hyperfine Structure of the 4d2D3/2,5/2 Levels and Isotope Shifts of the 4p2P3/2 - 4d2D3/2 and 4p2P3/2 - 4d2D5/2 Transitions in Gallium 69 and 71
S.J. Rehse, W.M. Fairbank Jr.,
and S.A. Lee
Department of Physics,
Colorado State University, Fort Collins, Colorado 80523
The hyperfine structure of the 4d2D3/2,5/2 levels of 69,71Ga has been determined. The 4p2P3/2 - 4d2D3/2 (294.50 nm) and 4p2P3/2 - 4d2D5/2 (294.45 nm) transitions were studied by laser induced fluorescence in an atomic Ga beam. The hyperfine A constant measured for the 4d2D5/2 level is 77.3+/-0.9 MHz for 69Ga and 97.9+/-0.7 MHz for 71Ga (3 sigma errors). The A constant measured for the 4d2D3/2 level is –36.3+/-2.2 MHz for 69Ga and –46.2+/-3.8 MHz for 71Ga. These measurements correct sign errors in the previous determination of these constants. For 69Ga, the hyperfine B constants measured for the 4d2D5/2 and 4d2D3/2 levels are 5.3+/-4.1 MHz and 4.6+/-4.2 MHz, respectively. The isotope shift was determined to be 114+/-8 MHz for the 4p2P3/2 - 4d2D3/2 transition and 115+/-7 MHz for the 4p2P3/2 - 4d2D5/2 transition. The lines of 71Ga are shifted to the blue. This is in agreement with previous measurement.
Applied Physics B, 70, 657, 2000
Optical Manipulation of Group III Atoms
S.J. Rehse, R.W. McGowan and S.A. Lee
Department of Physics, Colorado State University,
Fort Collins, Colorado 80523
We present details for the laser manipulation of group III atoms, specifically aluminum, gallium and indium. The practical considerations of accomplishing this manipulation are discussed and alternative schemes are presented for each species. The possibility of using such an optical technique for composition modulation during semiconductor growth for the fabrication of quantum wire and quantum dot structures is also discussed.
Applied Physics Letters, 71 (10), 1427, 8 September 1997,
Nanolithography with metastable neon atoms: Enhanced rate of contamination resist formation for nanostructure fabrication
S.J. Rehse, A. D. Glueck and S.A. Lee
Department of Physics, Colorado State University,
Fort Collins, Colorado 80523
A.B. Goulakov and C.S. Menoni
Department of Electrical Engineering, Colorado
State University, Fort Collins, Colorado 80523
D.C. Ralph
Department of Physics, Cornell University, Ithaca,
New York 14853
K.S. Johnson and M. Prentiss
Department of Physics, Harvard University, Cambridge,
Massachusetts 02138
We report a sevenfold improvement in the rate of contamination resist formation over previous experiments by using metastable neon atoms for nanolithography. Chemically assisted ion bean etching was used to transfer the resist pattern into the substrate. We demonstrate the fabrication of 50-nm-wide features in GaAs with well-defined edges and an aspect ration >2:1. These are the best resolution and highest aspect ratio features that have been achieved with metastable atom lithography. The resist formation rate by the metastable neon atoms and the etch selectivity of the contamination resist with GaAs were measured.
Physical Review A, 52 (5), 3966, November 1995
Theoretical and experimental study of the Bragg scattering of atoms from a standing light wave
David M. Giltner, Roger W. McGowan and Siu Au Lee
Department of Physics, Colorado State University,
Fort Collins, Colorado 80523
We study up to the sixth order of Bragg deflection of metastable neon atoms from a standing light wave, corresponding to a momentum transfer of 12 hbar-k. We derive an analytical result for the scattering probability, suitable for arbitrarily high Bragg order, and demonstrate its agreement with experimental results. We investigate the effect of velocity distribution on the Bragg process and show that overlapping diffraction orders can be resolved in velocity space. The prospect of using Bragg scattering as the optics in a Mach-Zender style atom interferometer with large splitting is discussed.
Physical Review Letters, 75 (14), 2638, 2 October 1995
Atom interferometer based on Bragg scattering from standing light waves
David M. Giltner, Roger W. McGowan and Siu Au Lee
Department of Physics, Colorado State University,
Fort Collins, Colorado 80523
We have constructed an atom interferometer by Bragg deflecting a collimated beam of metastable neon atoms from three parallel standing waves. Interference fringes have been observed using atoms Bragg scattered at up to the third order, giving a maximum of 6 hbar-k transverse momentum difference between the two arms of the interferometer. In the first order case we have achieved a fringe contrast of 62% and a peak to peak signal of 1700 atoms/s. We believe this to be the highest fringe contrast that has been achieve in atom interferometers.
Optics Letters, 20, 2535, 1995
Light force cooling, focusing, and nanometer-scale deposition of aluminum atoms
Roger W. McGowan, David M. Giltner, and Siu Au Lee
Department of Physics, Colorado State University,
Fort Collins, Colorado 80523
We deposited neutral-aluminum atoms in thin parallel lines to form a grating with a line separation 154.7 nm by using near-resonance laser light and direct-write optical lithography techniques. We did this by using the single-frequency closed UV transition from the second ground state 3p2P3/2(F=4) to 3d2D5/2(F=5) at 309.4 nm. The aluminum features were analyzed with an atomic force microscope.
Physical Review Letters, 70 (3), 251, 18 January 1993
New measurement of the relativistic Doppler shift in neon
Roger W. McGowan, David M. Giltner, Scott J. Sternberg
and Siu Au Lee
Department of Physics, Colorado State University,
Fort Collins, Colorado 80523
We report on a new measurement of the relativistic doppler shift in neon. We measured the frequency difference between a two-photon transition in a fast beam and a slow beam. The result is compared to the predication of special relativity. The experiment represents a more than tenfold improvement over other Doppler shift measurements and verifies the time dilation effect at an accuracy level of 2.3 ppm.
Ph.D. dissertation, Department of Physics, Colorado State University, summer 1996
Light force cooling, manipulation and nanometer-scale deposition of neutral aluminum atoms
Roger W. McGowan
Department of Physics, Colorado State University,
Fort Collins, Colorado 80523
Ph.D. dissertation, Department of Physics, Colorado State University, spring 1996
An interferometer for atoms using Bragg scattering from standing light waves
David M. Giltner
Department of Physics, Colorado State University,
Fort Collins, Colorado 80523