Optical element, refractive index sensor, refractive index sensor array, and biosensor

摘要

An optical element for resonating and reflecting incident light having a wavelength includes a periodic structure formed of protrusions and recessions. A period of the periodic structure is equal to or less than the wavelength of the incident light. The incident light having the wavelength is resonated and reflected by a resonance caused between the incident light and the protrusions and recessions. Widths of the protrusions are spatially changed.