Light-induced atomic desorption for miniaturization of magneto-optical sensors S. Gateva 1* , M. Taslakov 1 , V. Sarova 1 , E. Mariotti 2 , S. Cartaleva 1 1 Institute of Electronics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia, Bulgaria 2 Physics Department, University of Siena, and CNISM, via Roma 56, 53100 Siena, Italy ABSTRACT An investigation of the influence of light-induced atomic desorption (LIAD) on the transmission spectra from point of view of LIAD application for miniaturization of magneto-optical sensors and anti-relaxation coatings diagnostics is reported. With reduction of the dimensions of the cells, the amplitude of the signals decreases and it can be compensated by increasing the atomic density with temperature using special high temperature anti-relaxation coatings, or by LIAD. LIAD is a non-thermal process in which atoms adsorbed at a surface are released under illumination. It is investigated in various papers and has different applications - vapor density stabilization, MOT loading, surface nanostructuring etc. In this work the dependence of the shape of the absorption spectra on the laser power and blue light power is measured and analysis of the influence of different factors is done. All measurements are performed on the Rb D2 line in 3 different vacuum cells (uncoated, paraffin coated and SC-77 coated) with a 460 nm light emitting diode illumination. The good knowledge of the factors influencing the alkali atom spectra will be useful not only for the development of new all- optical sensors, but for study atom-dielectric surface interactions and development of new all-optical methods for surface and coating diagnostics. Keywords: light induced atomic desorption, anti-relaxation coating, magneto-optical sensors miniaturization, atomic spectroscopy, alkali atoms 1. INTRODUCTION Many papers have been devoted to the development of high sensitive alkali vapor magneto-optical sensors and their miniaturization for different applications 1 . The bad consequences of the size reduction are: i) a resonance width broadening, ii) a signal amplitude decrease. For the first point, an anti-relaxation coating of the cell removes the resonance broadening due to higher atom-wall collision rates 2-5 . For the second one, the decrease in the resonance amplitude can be compensated by increasing the atomic density with the temperature of the cell using special high temperature anti-relaxation coatings 6 . An alternative way to increase the alkali atom density is by light-induced atomic desorption (LIAD) 7-9 . LIAD is a non-thermal process in which atoms adsorbed at a surface are released under illumination. It has been investigated in many dedicated works and has already a wide range of research applications, as, for example, vapor density stabilization 10 , MOT loading 11 , cluster formation control 12 . There are many parameters influencing the LIAD, among which the cell dimensions and geometry, the wavelength of the illuminating light, the alkali atom species, the cell’s history 13 . This work presents an investigation of the influence of LIAD on the transmission spectra aimed at LIAD application for miniaturization of magneto-optical sensors. All measurements are performed on the Rb D 2 line (780 nm) in 3 different vacuum cells (uncoated, paraffin coated and SC-77 coated) with a 460 nm light emitting diode illumination. The dependence of the shape of the spectra on both the 780 nm laser and blue light intensities is measured and analysis of different factors is done. The good knowledge of the features influencing the alkali atom spectrum will be useful not only for the development of new all-optical sensors, but for the study of atom-dielectric surface interactions and the development of new all-optical methods for surface and coating diagnostics. 14,15 *sgateva@ie.bas.bg; phone +359 2 9795924; fax +359 2 9753201 17th International School on Quantum Electronics: Laser Physics and Applications, edited by Tanja Dreischuh, Albena Daskalova, Proc. of SPIE Vol. 8770, 87700O © 2013 SPIE · CCC code: 0277-786X/13/$18 · doi: 10.1117/12.2014408 Proc. of SPIE Vol. 8770 87700O-1