OPTICAL ELEMENT AND METHOD FOR MANUFACTURING THE SAME

Title:

OPTICAL ELEMENT AND METHOD FOR MANUFACTURING THE SAME

Document Type and Number:

Japanese Patent JP2012108352

Kind Code:

A

Abstract:

To provide an optical element having high optical characteristics.

The optical element includes a dielectric layer 2 on a principal surface of a light-transmitting substrate 1, and a plurality of projections 11 formed on the dielectric layer 2, the projections having a width smaller than a wavelength of visible light. The projections 11 include a metal layer 3 comprising Al on the dielectric layer 2, and a mask layer 4 formed of SiO₂ or a cermet containing SiO₂, contacting an upper face of the metal layer 3. By providing the mask layer 4 comprising a dielectric material in contact with the metal layer 3, processing accuracy of the metal layer 3 can be kept high even when a resist mask used for the processing of the metal layer 3 has a low mask pattern height, and thereby, the obtained optical element has excellent optical characteristics.