A method of periodically poling LiTaO, single crystal at room temperature by applying an external pulsed field is proposed. The relationship between the growth of inverted domains and switching current as well as switching time has been studied. The growth of inverted domains can be controlled by the duration of the pulsed field. The domain structure with period A>8pm has been fabricated in a 0.3mm-thick plate of LiTa03 by partial switching.

Quasi-phase-matching optical parametric and cascaded parametric processes in a two-component quasiperiodic superlattice were studied in theory and experiment. This letter demonstrates how to obtain red at 666nm and blue at 443 nm simultaneously from the superlattice using a 532nm laser as a pump through these two processes mentioned above. The result confirms that some nonlinear frequency conversion processes occurring in a high-dimension x(2) nonlinear photonic crystal may be efficiently achieved in such a one-dimension quasiperiodic optical superlattice.

An efficient generation of red light in a periodically-poled nearly-stoichiometric LiTaO3 (PPSLT) by extracavity single-pass frequency doubling of a diode-pumped, Q-switched Nd: YVO4 laser at 1342nm was realized. An average power of 1.4W of the 671nm red light is obtained at the fundamental power of, 2.8W with the conversion efficiency of 50%. The high conversion efficiency and steady output of red light indicate that the thick PPSLT is a competitive candidate for frequency conversion in order to construct a compact all-solid-state red laser.