These include polarization-maintaining fiber and fiber designed to suppress whispering gallery mode propagation. The rotunda features a seemingly unlikely whispering gallery. In 1989, he suggested high-Q optical microcavities with whispering gallery modes. A hemispherical enclosure will also guide whispering gallery waves. It has four seven-storeyed corner towers, each opening on to a unique "whispering gallery". It has an astonishing whispering gallery and it covers an area of . The school library is a "whispering gallery" because of its domed ceiling. Chip-scale OEOs utilize whispering gallery mode optical resonators rather than a delay line.