Laser cleaning and Raman analysis of the contamination on the optical window of a rubidium vapor cell

Patrik Gádoros; Aladár Czitrovszky; Attila Nagy; Roman Holomb; László Kocsányi; Miklós Veres

doi:10.1038/s41598-022-19645-z

Laser cleaning and Raman analysis of the contamination on the optical window of a rubidium vapor cell

Sci Rep. 2022 Sep 15;12(1):15530. doi: 10.1038/s41598-022-19645-z.

Authors

Patrik Gádoros¹, Aladár Czitrovszky², Attila Nagy², Roman Holomb^{2

3}, László Kocsányi⁴, Miklós Veres²

Affiliations

¹ Department of Atomic Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem Rkp. 3, 1111, Budapest, Hungary. gadoros.patrik@ttk.bme.hu.
² Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Konkoly Thege M. Str. 29-33, 1121, Budapest, Hungary.
³ Uzhhorod National University, Zankoveckoyi, 89a Str., Uzhhorod, 88015, Ukraine.
⁴ Department of Atomic Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem Rkp. 3, 1111, Budapest, Hungary.

Abstract

In this work, we present the laser cleaning of a Rubidium vapor cell and the Raman analysis of the contaminant material to be removed. The optical window of the vapor cell had gradually lost transparency due to the development of an opaque layer of unknown composition at the inner side during the normal operation of the cell. Laser cleaning was successfully performed by a frequency-doubled Nd:YAG laser focusing the beam inside the cell, avoiding any possible damage to the window. A single laser pulse was enough to clear away the black discoloration at the focal spot and locally restore the transparency of the window. The Raman spectra of the deposit showed peaks not yet described in the literature. Comparison with known Rubidium germanate spectra and simulation results strongly suggested that the unknown material was Rubidium silicate.