Absorption cells for spectroscopy and etalons of optical frequencies
Absorption cells are made primarily for laser spectroscopy of gasses and to be used as references for laser frequency stabilization onto selected spectral components. The production technology of absorption cells in ISI is realized in a specialized glassmaking workshop, and the cells are custom designed mostly for national metrological institutions such as PTB in Germany, NIST in the USA and BIPM in France.
Examples and parameters of manufactured cells:
- Cells made of quartz glass with wedged windows with antireflection coated inner and outer window surfaces or with windows under the Brewster angle.
- Cells filled with superpure gasses (acetylene 13C2H2, methane, xenon, krypton) or saturated vapor of iodine, cesium, rubidium, etc. Cells filled with iodine serve as s reference for the primary etalons of (wave)length. The frequency shifts of iodine cells made at ISI are the smallest in the world (below 1 kHz of the optical frequency). The technology of the ISI allows the preparation of cells filled with various media based on application requirements.
