Waveguide wavelength dielectric

Especially at optical wavelengths, dielectric fibers are commonly used to guide waves. In this section, we develop the properties of waves guided by a fileslib. The guide wavelength in waveguide is longer than wavelength in free space. This isn't intuitive, it seems like the dielectric constant in waveguide must be How do you find waveguide wavelength? The guided wavelength is λ g =2π / β g and the ε r -medium wavelength is λ =2π / k.
Dielectric waveguide applications include integrated optical systems, optical communications (optical fibers), and shorter millimeter-wavelength
We first consider a simple cylindrical-core hollow dielectric waveguide as shown When the radius of the hole is on the order of the optical wavelength,