| 摘要 |
PURPOSE:To obtain short-wavelength coherent light of high output by making efficient wavelength conversion of a semiconductor laser beam by a nonlinear optical element. CONSTITUTION:Optical coupling elements 2 which are the laminates formed by alternately laminating high-refractive index layers and low-refractive index layers are so constituted that the high-refractive index layers are thicker than the low-refractive index layers in the central part, that the former is gradually thinner and the latter is conversely thicker the furtherer from the center and that the relation between both is exactly opposite from the relation in the central part. These optical coupling elements 2 are adjacently disposed in such a manner that the laminated surfaces thereof intersect orthogonally with each other. The laser beam emission surfaces of the optical coupling elements 2 are tightly coupled to each other in such a manner that the active layers of a semiconductor laser parallels with the central high-refractive index layer of the optical coupling elements 2. The waveguide type nonlinear optical element 3 is tightly coupled to the high-refractive index layer in the central part of the optical coupling element 2 on the side opposite therefrom. The disposition is so adjusted that the laser beam is efficiently made incident on the waveguide of the nonlinear optical element. As a result, the output light of the semiconductor laser is efficiently guided to the waveguide nonlinear optical element from the semiconductor laser and, therefore, the higher harmonic coherent light of the high output and short wavelength is obtd. |
