Whispering-gallery wave known as surface plasmons has been demonstrated in the form of whispering-gallery waves, and likewise for exciton-polaritons in semiconductors. Galleries simultaneously containing both acoustic and optical whispering-gallery waves have also been made, exhibiting very strong mode coupling and coherent effects. Hybrid solid-fluid-optical whispering-gallery structures have been observed as well. Whispering-gallery wave Whispering-gallery waves, or whispering-gallery modes, are a type of wave that can travel around a concave surface. Originally discovered for sound waves in the whispering gallery of St Paul’s Cathedral, they can exist for light and for other waves, with important applications in nondestructive testing, lasing, cooling and sensing,
National Gallery in Prague National Gallery in Prague The National Gallery in Prague () is a state-owned art gallery in Prague, which manages the largest collection of art in the Czech Republic. The collections of the gallery are not housed in a single building, but are presented in a number of historic structures within the city of Prague, as well as other places. The largest of the gallery sites is the Veletržní Palác, which houses the National Gallery's collection of modern art. It is one the largest museums in Central Europe. The history of the National Gallery dates back to the end of the