Narrow band optical filter using Goos–Hänchen shift in a cascaded waveguide structure

• We proposed a cascaded waveguide structure.
• We confirmed great enhanced Goos–Hänchen shift in our structure.
• We realized an ultra-narrow bandwidth filter.

An narrow band optical filter based on an enhanced Goos–Hänchen shift utilizing cascaded waveguide structure is proposed. We demonstrate in an experiment that a filter with 3 dB bandwidth of 0.19 nm and extinction ratio of 6.7 dB around a light wavelength of 859 nm is realized.