| 摘要 |
PURPOSE:To obtain high efficiency by forming a ring resonance type waveguide of a 1st and a 2nd optical waveguide on a substrate and converting all of wavelength-converted light, which is emitted from the entire periphery of the 2nd optical waveguide, into parallel light or a beam having the same focus by a grating. CONSTITUTION:On the reverse surface or top surface of the substrate 30, the grating 40 is formed which shapes the waveform of the higher harmonic light or sum frequency light emitted from the entire periphery of the 2nd optical waveguide 34 into the light which passes the same focus or parallel light. Therefore, higher harmonics from the entire periphery of the 2nd waveguide 34 including a curved part can be utilized and the optical waveguides are formed in circular shapes which are as small as possible so as to minimize the sum of the curvature loss and propagation loss of the optical waveguides, thereby increasing resonance magnitude. Consequently, the efficiency can be improved more than the mere utilization of the wavelength-converted light from the entire periphery. |
