Second-harmonic generation in a direct-bonded periodically poled LiNbO_3 buried waveguide

Abstract

We report the fabrication of a 12-mum -thick periodically poled LiNbO(3) planar waveguide buried in LiTaO(3) by direct bonding of precision-polished surfaces. Frequency doubling of the 1064-nm output of a cw diode-pumped Nd:YAG laser was performed in a 5.5-mm-long device with a 6.50-mum -period grating at an elevated temperature of 174 degrees C. The resultant green second-harmonic output exhibited fundamental-spatial-mode characteristics at a 4.3%W(-1) conversion efficiency.

Mode overlap analyses of propagated waves in direct bonded PPMgLN ridge waveguide

“…Direct-bonded ridge-waveguide devices have been studied to overcome these limitations described as above [3][4][5][6]. The ridge waveguide neither shows the degradation of the nonlinear coefficient nor photorefractive damage because no ion-exchange process employed in the process.…”

Fabrication of Thick Periodically-poled Lithium Niobate Crystals by Standard Electric Field Poling and Direct Bonding

“…Directbonding of various materials has been investigated for fabricating optical devices such as waveguides [8]. A buried waveguide was made by direct-hetero-bonding of lithium niobate and lithium tantalate crystals [9], and efficient SHG has been obtained with a similarly fabricated buried PPLN waveguide [10]. In this work, we utilized a similar directbonding method to make a large-aperture PPLN device for the demonstration of "slanted QPM" SHG.…”

Hysteresis-free high-temperature precise bimorph actuators produced by direct bonding of lithium niobate wafers

“…19,20 It was shown recently that the direct wafer bonding allows to increase the aperture of the periodically poled LN 21 and to produce the buried waveguides. 22 The direct bonding process is based on chemical bonds appearing between two flat surfaces without using any intermediate layers. The direct bonding of two aligned LN wafers with the opposite direction of spontaneous polarization provides an equivalent of the bidomain wafer.…”