Laser Dyes

Abstract

Laser technology is another area in which organic dyes are beginning to find application. The first continuous laser was demonstrated in 1961 and operated in the near infrared spectrum.¹ Since then, several inorganic lasers have been developed which emit from the ultraviolet through the visible into the near and far infrared regions of the electromagnetic spectrum (Fig. 3.1.). However, the fact that these inorganic lasers emit only at very few specific wavelengths is an obvious drawback. In contrast, dye lasers cover the entire visible and near infrared spectrum from <400 nm to 1000 nm and have a far greater tunability than the inorganic lasers. In contrast to inorganic lasers, which emit very narrow bands (Fig. 3.1), dye lasers emit a broad band of radiation. This means that any lasing wavelength, whether narrow or broad, can be obtained from dye lasers by using appropriate filters (wavelength selectors). Consequently, dye lasers have become increasingly popular, especially in the field of Raman spectroscopy.^2,3