EXTERNAL-CAVITY FREQUENCY-STABILIZATION OF VISIBLE AND INFRARED SEMICONDUCTOR-LASERS FOR HIGH-RESOLUTION SPECTROSCOPY

We have shown that external cavity stabilization can be a straightforward and powerful technique for converting diode lasers of poor spectral quality into useful tools for high precision laser spectroscopy. The method requires an anti-reflection coating on one facet of the diode laser but, contrary to popular belief, this is not difficult and does not require any specialized equipment. We describe a coating procedure which can be used with standard commercial diode lasers. We have demonstrated the external cavity method using diodes at a variety of visible and infrared wavelengths. Details are given for a visible laser centered at 670 nm.