Intracavity laser spectroscopy: propagation of absorption data through optical fibers

The propagation of achromatic visible laser radiation through optical fibers is examined for a quasi-cw dye laser designed to record absorption by intracavity laser spectroscopy (ILS). The wavelength and intensity characteristics of the ILS laser output and any superimposed intracavity absorption features are preserved quantitatively for propagation through an extracavity single-mode optical fiber. Feedback from the front surface of the optical fiber and its associated optics can modify the ILS laser output. Two optical configurations which give no noticeable modifications to the IS data propagated through the optical fiber are described. Applications of ILS for remote sensing, sensitive detection of extracavity feedback effects, and characterization of extracavity interferometric signals are indicated.