Frequency noise analysis of semiconductor lasers

摘要

For a fundamental etalon of optical frequency based on the external-cavity semiconductor laser (ECL), not only the long-term frequency stability but also the linewidth seems to be an important parameter. The linewidth broadening is dominated by fluctuations (noise) of the optical frequency. Parameters of these fluctuations and their spectral characteristics are crucial information for their suppression. We present an experimental setup for the frequency noise measurements designed for a free running 633 nm ECL with a stabilized reference He-Ne laser. We observed the corner frequency of the 1/f noise of the ECL of approx. 10 MHz. No significant spectral components over the 1/f noise corner frequency were found.