We constructed diffusion-bonded stacks of periodically poled lithium n
iobate (PPLN). Such crystals combine the advantages of planar processi
ng used to make PPLN wafers with the power handling capability of larg
e apertures. We demonstrated an optical parametric oscillator that use
s a 3-mm-thick diffusion-bonded stack consisting of three 1-mm-thick P
PLN crystals. (C) 1998 Optical Society of America.