| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a wavelength conversion element, wherein conversion efficiency is heightened by making electric field peak positions of signal light and conversion light coincide with each other, and the tolerance of the width of an optical waveguide by which the signal light and conversion light can hold a single mode is made larger than those of conventional types. <P>SOLUTION: In the wavelength conversion element 10 provided with the optical waveguide 18, the optical waveguide is so constituted that a high-refractive index region 14 which is provided in a ferroelectric crystal 12, having a periodical polarization inversion structure 20 formed and having a first refractive index N1 and has a second refractive index N2; and a structural body 16, provided along a light propagation direction on an upper surface 14a of the high-refractive index region and having a third refractive index N3 are placed in a medium 11, having a fifth refractive index N5 and the first, the second, the third and the fifth refractive indices satisfy N2>N1>N5 and N1≥N3>N5. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
