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

Wavelength

In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...

 of the light.

Zero-mode waveguides have been developed for rapid parallel sensing of zeptolitre sample volumes, as applied to gene sequencing

Gene sequencing

Gene Sequencing may refer to:* DNA sequencing* or a comprehensive variant of it: Full genome sequencing...

, by Pacific Biosciences

Pacific Biosciences

Pacific Biosciences is a biotechnology company founded in 2004 that develops and manufactures systems for gene sequencing and some novel real time biological observation. They describe their platform as single molecule real time sequencing , based on the properties of zero-mode waveguides...

 (previously named Nanofluidics, Inc.)

A waveguide operated at frequencies lower than its cutoff frequency

Cutoff frequency

In physics and electrical engineering, a cutoff frequency, corner frequency, or break frequency is a boundary in a system's frequency response at which energy flowing through the system begins to be reduced rather than passing through.Typically in electronic systems such as filters and...

 (wavelengths longer than its cutoff wavelength) and used as a precision attenuator is also known as a "waveguide below-cutoff attenuator."