A calcium vapor cell for atomic spectroscopy

Abstract

A calcium vapor cell used in laser spectroscopy usually suffers from calcium coating on the cell windows. To solve the problem, we add two mirrors in the cell to reflect the laser beam, then the calcium will coat on these mirrors instead of on the windows. Calcium coating degrades the reflectivity of the mirrors at the beginning, but the mirrors become calcium mirrors after a certain period of coating and their reflectivity will not change by further calcium coating. Using this cell in a conventional saturated-absorption spectroscopy, the observed saturated-absorption peak at 657 nm is about 2.4% of the probe beam power and its linewidth is below 300 kHz. Therefore, a portable secondary calcium-wavelength standard at 657 nm having an accuracy better than 1x10(-11) is possible. In addition, our cell has a continuous working time longer than 3 d and it can be easily extended to 10 d. (C) 2002 American Institute of Physics.