Abstract
This paper reviews the oscillation wavelength stabilization of a semiconductor laser using an atomic absorption line that is an accurate and stable wavelength reference. The strong absorption lines of cesium and rubidium atoms have been used as wavelength references for semiconductor laser wavelength stabilization because these lines are in the oscillation wavelength range of a semiconductor laser. A saturated absorption spectroscopy method has been applied to the stabilization because it provides a narrow Doppler free absorption spectrum as the wavelength reference. Wavelength stabilization under high speed modulation is required for coherent optical communication. On the other hand, wavelength stabilization without any frequency modulation is required for application fields which need a narrow oscillation linewidth. The wavelength stabilization using an atomic absorption line satisfies these requirements by using some control electronic circuits and/or magneto-optic effects, i.e., the Zeeman and the Faraday effects.
