Domain reversal of periodically poled LiNbO3 with a shorter domain inverted period

Abstract

Periodically poled LiNbO3 (PPLN) was fabricated with a 7.3 mu m domain-inverted period, a 1.5 mu m thick photoresist grating and a 3 mu m pattern open width through the electric field poling process using the liquid electrode technique. After slicing the wafers to a final dimension of 30 x 10 mm(2), the specimen was poled and then annealed. Second harmonic generation (SHG) was investigated to evaluate the domain reversal properties of the PPLN. The fundamental and second harmonic waves of a 7.3 mu m PPLN waveguide were 1087 +/- 1 nm and 544 +/- 0.5 nm, respectively. The average duty cycle of the etched PPLN was estimated to be 50.6 +/- 3.3%. For PPLN in Ti:LN waveguide with a 6.8 mu m domain-inverted period, the fundamental guided-mode wave and the radiated SHG wavelength were 1068 nm and 534 run. The SHG power increased proportionally to the square of the input pumping power. 330 mu W of SHG power was observed for a coupled power of 29 mW with a conversion efficiency of 1.138%. The average duty cycle of the etched PPLN was determined to be 50.2%. (C) 2007 Elsevier B.V. All rights reserved.