We observed cw third-harmonic generation in a periodically poled LiNbO3 crystal by cascading optimally phase-matched second-harmonic and sum-frequency generation. Other processes, such as fourth-harmonic generation, are allowed by the flexibility of quasi-phase matching. We demonstrate a divide-by-nine (1.19– 10.71-µm) frequency chain that uses only two lasers.
© 1997 Optical Society of America
O. Pfister, J. S. Wells, L. Hollberg, L. Zink, D. A. Van Baak, M. D. Levenson, and W. R. Bosenberg, "Continuous-wave frequency tripling and quadrupling by simultaneous three-wave mixings in periodically poled crystals: application to a two-step 1.19–10.71-µm frequency bridge," Opt. Lett. 22, 1211-1213 (1997)