The direct fourth harmonic generation (FHG) is theoretically demonstrated based on quasi-phase-matching (QPM) configuration in periodically poled lithium tantalate (PPLT). The wavelength dependence of the period of FHG QPM gratings is calculated. Bandwidths of fundamental wavelength, temperature, and incident angle are also studied. A very wide bandwidth, as large as 119.5 nm, of fundamental wavelength near 3699 nm is found with the QPM period of 9.442 ?m and the crystal length of 1 cm.
© 2005 Chinese Optics Letters
Wei Xie, Xianfeng Chen, Like He, Yuping Chen, and Yuxing Xia, "Theoretical study of quasi-phase-matching fourth harmonic generation in periodically poled lithium tantalate," Chin. Opt. Lett. 2, 664-666 (2004)