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Title: Two-frequency acousto-optic modulator driver to improve the beam pointing stability during intensity ramps

Abstract

We report on a scheme to improve the pointing stability of the first order beam diffracted by an acousto-optic modulator (AOM). Due to thermal effects inside the crystal, the angular position of the beam can change by as much as 1 mrad when the radio-frequency power in the AOM is reduced to decrease the first order beam intensity. This is done, for example, to perform forced evaporative cooling in ultracold atom experiments using far-off-resonant optical traps. We solve this problem by driving the AOM with two radio frequencies f{sub 1} and f{sub 2}. The power of f{sub 2} is adjusted relative to the power of f{sub 1} to keep the total power constant. Using this, the beam displacement is decreased by a factor of 20. The method is simple to implement in existing experimental setups, without any modification of the optics.

Authors:
; ; ; ; ; ; ;  [1]
  1. 5. Physikalisches Institut, Universitaet Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart (Germany)
Publication Date:
OSTI Identifier:
20953407
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 78; Journal Issue: 4; Other Information: DOI: 10.1063/1.2720725; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ATOMS; BEAMS; CRYSTALS; DIFFRACTION; EVAPORATION; EVAPORATIVE COOLING; LASERS; MODULATION; OPTICS; RADIATION PRESSURE; RADIOWAVE RADIATION; STABILITY; TEMPERATURE DEPENDENCE

Citation Formats

Froehlich, B., Lahaye, T., Kaltenhaeuser, B., Kuebler, H., Mueller, S., Koch, T., Fattori, M., and Pfau, T. Two-frequency acousto-optic modulator driver to improve the beam pointing stability during intensity ramps. United States: N. p., 2007. Web. doi:10.1063/1.2720725.
Froehlich, B., Lahaye, T., Kaltenhaeuser, B., Kuebler, H., Mueller, S., Koch, T., Fattori, M., & Pfau, T. Two-frequency acousto-optic modulator driver to improve the beam pointing stability during intensity ramps. United States. doi:10.1063/1.2720725.
Froehlich, B., Lahaye, T., Kaltenhaeuser, B., Kuebler, H., Mueller, S., Koch, T., Fattori, M., and Pfau, T. Sun . "Two-frequency acousto-optic modulator driver to improve the beam pointing stability during intensity ramps". United States. doi:10.1063/1.2720725.
@article{osti_20953407,
title = {Two-frequency acousto-optic modulator driver to improve the beam pointing stability during intensity ramps},
author = {Froehlich, B. and Lahaye, T. and Kaltenhaeuser, B. and Kuebler, H. and Mueller, S. and Koch, T. and Fattori, M. and Pfau, T.},
abstractNote = {We report on a scheme to improve the pointing stability of the first order beam diffracted by an acousto-optic modulator (AOM). Due to thermal effects inside the crystal, the angular position of the beam can change by as much as 1 mrad when the radio-frequency power in the AOM is reduced to decrease the first order beam intensity. This is done, for example, to perform forced evaporative cooling in ultracold atom experiments using far-off-resonant optical traps. We solve this problem by driving the AOM with two radio frequencies f{sub 1} and f{sub 2}. The power of f{sub 2} is adjusted relative to the power of f{sub 1} to keep the total power constant. Using this, the beam displacement is decreased by a factor of 20. The method is simple to implement in existing experimental setups, without any modification of the optics.},
doi = {10.1063/1.2720725},
journal = {Review of Scientific Instruments},
number = 4,
volume = 78,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}