Zero-mode waveguide
A zero-mode waveguide is an optical waveguide that guides light energy into a volume that is small in all dimensions compared to the wavelength of the light.
Zero-mode waveguides have been developed for rapid parallel sensing of zeptolitre sample volumes, as applied to gene sequencing, by Pacific Biosciences
A waveguide operated at frequencies lower than its cutoff frequency and used as a precision attenuator is also known as a "waveguide below-cutoff attenuator."
