Optical element, light emitting device and method for producing optical element

摘要

The present invention relates to an optical element for converting light of prescribed wavelength emitted from a light source into light of wavelength different from the prescribed wavelength for outputting. A first crystal part ( 20 ) and a second crystal part ( 21 ) having respective surfaces opposed to each other whose coefficients of linear expansion are different by 5 ppm or more are optically polished so that the surfaces opposed to each other include crystallographic axes. An acrylic adhesive whose glass transition point is 75° C. or lower is applied to the adhesive surface of the first crystal part ( 20 ) or the second crystal part ( 21 ) to stick the first crystal part ( 20 ) and the second crystal part ( 21 ) to each other. The adhesive is irradiated with light to cure the adhesive and form an adhesive layer ( 22 ) having a refractive index of 1.52 or lower. Then, the first crystal part and the second crystal part stuck to each other are cut into a desired size to form the optical element. In the optical element, the separation of the adhesive layer ( 22 ) for connecting the first crystal element to the second crystal element and the damage of the crystal parts are suppressed.