Abstract

Red-green tunable lasers are required for a range of applications in dermatology, remote sensing, and surf zone imaging. Here we report the demonstration of an efficient route to tunability in this region based upon frequency-doubling of a pulsed Nd:YAG pumped $\text{LiF}:{\text{F}}_2^{–}$ color center laser in non-critically phase-matched (NCPM) lithium triborate (LBO). By optimizing both the $\text{LiF}:{\text{F}}_2^{–}$ laser and frequency-doubling stages, we obtain substantially higher overall optical-optical conversion efficiencies than previously reported^1,2 for this route. A two-stage conversion efficiency of > 20% from 1064 nm to broadly tunable visible light is realized. In comparison with competing schemes for tunable visible laser light, the approach reported here eliminates the strict spatial and spectral requirements that OPOs place on the pump laser, and overcomes the restricted longevity and poor beam quality of solid state dye lasers.

© 2000 IEEE