| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a wavelength conversion element which has excellent stability and may be easily produced by providing the end face of a wavelength conversion stage with a reflection stage in connection therewith and reflecting input light and control light by this reflection stage. SOLUTION: This element has an optical waveguide layer 41 disposed at a substrate 39 and the wavelength conversion stage 47 formed integrally therewith along this optical waveguide layer 14. The end face on the side opposite to the one end face on the side where the light of the wavelength conversion stage 47 goes in and out is provided with the reflection stage 38. The reflection stage 38 has a wavelength selection section 49, a polarization plane rotating section 51 and a reflection section 53 successively along the extension direction of the optical waveguide layer 41 from the side near the wavelength conversion stage 47. The input light transmits the polarization plane rotating section 51 twice forward (forward path) and backward (backward path). The light passes the polarization plane rotating section 51 back and forth, by which the polarization plane is rotated about 90 deg.. As a result, the polarization independence on the input light of the element is made possible.</p> |
