Attenuator for attenuating wavelengths unequal to a used wavelength

摘要

There is provided an attenuator for attenuating electromagnetic radiation of wavelengths Unequal to a used wavelength, including a grating element having i) grating grooves that produce a grating period (p), and ii) a grating plane. The grating period (p) is least about 150 times higher than the used wavelength.