| 摘要 |
PURPOSE:To obtain the second higher harmonic and a sum or difference frequency with high conversion efficiency, by using an optical fiber as a nonlinear medium to satisfy the phase matching condition with an optical waveguide type converting element without utilizing the double refractivity of crystal. CONSTITUTION:In respect to a device for wavelength conversion of a laser light which is used as a light source for measurement of transmission characteristics of optical fibers for optical communication or various spectrometries, a light wavelength converting element which converts the incident laser light of an angular frequency W1 to the second higher harmonic of an angular frequency W3(=2W1) by the secondary nonlinear polarization effect consists of an optical fiber, and the diameter of the code and the specific refractive index difference (DELTA=(n1<2>-n2<2>)/2n1<2>) of this optical fiber are set to satisfy expression DELTAbeta=beta3- 2beta1=O (phase matching condition) (beta1, beta3, n1, and n2 are the phase constant in the optical fiber of the incident laser light, the phase constant in the optical fiber of the second higher harmonic, the refractive index of the core of the optical fiber, and the refractive index of the clad of the optical fiber, respectively). |
