Development of a Portable Optical Frequency Comb and Application to Open-Path Atmospheric Measurement

In recent years, the application of the optical frequency comb (OFC) in environmental sensing using light has attracted significant attention. However, many studies have been conducted in metrology laboratories, where temperature and vibration disturbances are controlled. Among these developments, a research group at the National Institute of Standards and Technology (NIST) in the United States has demonstrated open-path atmospheric measurements spanning several kilometres using an OFC installed inside a building [1]. They have achieved atmospheric analysis outside the laboratory using an OFC in a trailer [2], [3]. However, as the demand for atmospheric measurements in agricultural fields and industrial sites continues to grow worldwide, reports utilizing an OFC as a light source remain limited. Therefore, this study aims to develop a portable OFC system suitable for open-path atmospheric measurements.