| 摘要 |
[Problem] To suppress variations in the wavelengths of grating elements that have been manufactured. [Solution] A grating element 1 is provided with: a support substrate 2 having one main surface 2a and another main surface 2b; a lower side cladding layer 3 provided on the one main surface 2a of the support substrate; an optical material layer 4, which is an optical material layer 4 provided on the lower side cladding layer 3, having a Bragg grating formed thereon; and a back surface layer 6 provided on the other main surface 2b of the support substrate. The lower side cladding layer 3 is formed from a material with refractive index of 1.69 or less. The optical material layer 4 is formed from a metal oxide with a refractive index of 1.70 - 3.50. The back surface layer 6 is formed from a material having a refractive index of 1.69 or less or a metal oxide having a refractive index of 1.70 - 3.50. |
