Bachelor defense by Jens Milan Nielsen

Absolute Frequency and Stability Characterization of a 1236 nm Laser - Using an optical frequency comb

In this project, an optical frequency comb was used to measure the absolute frequency of a 1236 nm laser and to characterize its frequency stability under both free-running operation and when locked to a wavelength-meter. These measurements were then used to evaluate the performance of the wavelength-meter lock. The results show that the wavelength-meter lock significantly improves the laser’s frequency stability on short time scales. However, the absolute frequency reported by the wavelength meter was found to differ from the frequency-comb measurement by at least 40 MHz. Together with the observed long-term drift, this discrepancy indicates that the wavelength meter suffers from limited absolute accuracy due to drift over time.