Practical Broad-Band Tuning of Dye Lasers by Solvent Shifting

Susan M Grenci,Ahmed H Zewail,George R Bird,Brian W Keelan

doi:10.1155/lc.6.361

Abstract

We have operated a dye laser over a broad wavelength range (593.8–667.0 nm) by shifting the dye emission profile with incremental changes of solvent composition. This was accomplished with the laser operating continuously, and only minor adjustment of the laser optics was required. Solvent tuning was facilitated by the critical dependence of the optimum laser wavelength on concentration of the second solvent. Using the known solvent-sensitive laser dye 9-diethylaminobenzo[a]phenoxaz-5-one (DBP), 87% of the tuning range from pure xylenes to pure methanol was covered by cumulative addition of 24 vol. % methanol to the starting xylenes solution. The optimum dye concentration was found to be independent of solvent composition, so that maximum laser power could be maintained by mixing equimolar dye solutions in the two solvents. These results establish the practicality of solvent-tuning as a method of conducting laser experiments over a broad wavelength range.

Highlights

In this paper we explore the practicality of tuning a dye laser over a broad range of wavelengths by incrementally varying solvent composition
Tion of optimal power and wide band tuning in a continuous dye laser experiment. It is important for practical solvent tuning that the spectral shift of the dye occurs continuously as solvent composition is changed, unlike the effect of chemical alteration of the chromophore
A wide tuning range can be covered by the addition of a modest volume of the second solvent, so the laser can be operated continuously during the solvent changes

Summary

Introduction

In this paper we explore the practicality of tuning a dye laser over a broad range of wavelengths by incrementally varying solvent composition. This method has been suggested earlier by the G&tingen group, and Halstead and Reeves[2] have optimized a coumarin dye for emission f Work by S.M.G. described completed at Rutgers University; present address: E.I. DuPont Co., Photoproducts Division, P.O. Box 267, Brevard, North Carolina 28712. $ Visiting Professor at California Institute ofTechnology; permanent address: Department of Chemistry, Rutgers University, New Brunswick, New Jersey 08903; author for correspondence.

Results

Discussion

Conclusion