Abstract

Quasi-phase-matching (QPM) structure can be used for many applications such as wavelength conversion and high speed optical signal processing. Field poling technique for LiNb0 3 (LN) has been developed and various types of nonlinear optic devices using periodically poled LN (PPLN) have been demonstrated. However, some problems such as photorefractive damage and high coercive field of ~2 1 kV/mm remain in PPLN. High coercive field makes difficult to fabricate large-cross-section PPLN device. Recently, MgO-doped LiNbO₃(M gO:LN) crystal has been investigated and developed because of its higher resistance to photorefractive damage than that of LN. Also, it has a large nonlinear coefficient and a lower coercive field of ~5 kV/mm ¹ than that of L . This means that MgO:LN is a suitable material for large-cross-section QPM nonlinear optic devices in high power range. In this paper, we demonstrate field polingof3 mm-thick MgO:LN crystal and characterize the process.

© 2002 Optical Society of America