Evaluation of optical frequency references quality - a way to efficient laser standards
- 1Akademie der Wissenschaften der Tschechischen Republik, Institut für wissenschaftliche Instrumente, Czech Academy of Sciences, Institute of Scientific Instruments
- 2Istituto Nazionale di Ricerca Metrologica, National Institute of Metrological Research
- 3Time-Space Reference Systems department (SYRTE), Paris Observatory
- 4Laboratoire de Physique des Lasers (CNRS-UMR 7538), Sorbonne Paris North University
Optical frequency references - absorption cells - represent an unique tool for laser frequency stabilization. They have an irreplaceable position in realization of laser standards, sources of light for laser interferometry – in these days the most precise dimensional measurement method. An usage of these references allows not only to reach stable laser sources, but also ensures the direct traceability of the measurement to fundamental standard. We present a development of new types of iodine absorption cells (with simplied design and technology and also cost reduction) intended mainly for less demanding systems. These references use approaches of using of new materials and technology of filling of absorption media to certain saturation pressure. Technological process is described in detail and performance of these cells is also discussed. The research was supplemented with development of novel method for evaluation of quality of the optical frequency references. This method is based on hyperfine transition lineshape measurement and overcomes difficulties and limits of traditionaly used laser induced fluorescence and absolute frequency measurement methods.