| 摘要 |
PURPOSE:To improve the conversion efficiency by superposing a thin membrane consisting of an organic substance whose refractive index is small and which has a large non-linear optical constant on a thin film optical waveguide and constituting an inorganic single crystal substrate whose refractive index is equal to or larger than the organic substance in higher harmonic wavelength lambda on said thin film. CONSTITUTION:The title element consists of a structure where a thin membrane optical waveguide 2 is provided on a substrate 1, an organic non-linear substance whose refractive index is smaller than that of the waveguide 2 is formed as a thin membrane on said waveguide, and also, an inorganic crystal substrate 4 whose refractive index is equal or larger in a higher harmonic wavelength area is provided on its organic thin film 3. In this state, by controlling the membrane thickness of the thin membrane optical waveguide 2, phase matching is taken, and also, by obtaining the thin membrane organic crystal of high quality, a higher harmonic whose conversion efficiency is high is generated. That is, when a fundamental wave is made incident on the optical waveguide 2, a higher harmonic is generated by Cerenkov radiation from the organic crystal thin film 3 brought into contact with the optical waveguide 2, and its higher harmonic passes through the inorganic crystal substrate 4 whose refractive index is equal to or larger than that of the organic crystal and emitted to the outside. In such a way, the higher harmonic whose conversion efficiency is high can be obtained. |
