| 摘要 |
PURPOSE:To surely prevent the sublimation or transforming of an org. nonlinear optical material at the end face of a waveguide part by providing a shielding layer at the end face of the element including the end face of the waveguide part consisting of the org. nonlinear optical material. CONSTITUTION:A laser beam (basic wave) 15 which is the divergent beam emitted from a semiconductor laser 16 as a basic wave generating means is collimated by a collimator lens 17 into collimated beams of light. Further, the collimated beams of light are condensed by a condenser lens 18 and are converged onto the end face of a core 11 at the small spot of the same diameter as the diameter of the core. The converged light is made incident on the inside of the optical wavelength conversion element 10. This basic wave 15 is converted by DMNP constituting the core 11 to a second harmonic wave 15' which is radiated into a clad 12. This wave repeats total reflection at the boundary between the outside surface thereof and the ambient medium and progresses inside the element 10 to the end face side. The beam 15'' including the second harmonic wave 15' is emitted from the exit end face 10b of the element 10. The beam 15'' is passed through a filter and only the second harmonic wave 15' is taken out. The element 10 is provided with the shielding layers 13a and 13b to avert the direct contact of the end face of the waveguide with the atmosphere, such as air, and, therefore, the sublimation and transforming of the core 11 are prevented. |
