An acousto-optic device comprising: an acousto-optic medium having a multi-layer nanostructure; and a sonic wave generator configured to apply sonic waves to the acousto-optic medium having the multi-layer nanostructure; wherein the acousto-optic medium having the multi-layer nanostructure comprises: a second layer formed of a second material and a third material that have different dielectric constants and repeatedly alternate with each other; a first layer disposed on a first surface of the second layer and formed of a first material ; and a third layer disposed on a second surface of the second layer and formed of a fourth material ; wherein each of the first material , the second material , the third material and the fourth material comprises a material selected from the group consisting of a gain material, a dielectric and a metal; and wherein at least one of the first material , the second material , the third material and the fourth material includes a metal; and wherein the acousto-optic device further comprises an optical coupling device configured to guide light (L) incident onto the acousto-optic medium having the multi-layer nanostructure to enable the light to propagate in the second layer , the optical coupling device comprising a prism or a diffraction grating layer disposed on a surface of the acousto-optic medium having the multi-layer nanostructure. an acousto-optic medium having a multi-layer nanostructure; and a sonic wave generator configured to apply sonic waves to the acousto-optic medium having the multi-layer nanostructure; wherein the acousto-optic medium having the multi-layer nanostructure comprises: a second layer formed of a second material and a third material that have different dielectric constants and repeatedly alternate with each other; a first layer disposed on a first surface of the second layer and formed of a first material ; and a third layer disposed on a second surface of the second layer and formed of a fourth material ; wherein each of the first material , the second material , the third material and the fourth material comprises a material selected from the group consisting of a gain material, a dielectric and a metal; and wherein at least one of the first material , the second material , the third material and the fourth material includes a metal; a second layer formed of a second material and a third material that have different dielectric constants and repeatedly alternate with each other; a first layer disposed on a first surface of the second layer and formed of a first material ; and a third layer disposed on a second surface of the second layer and formed of a fourth material ; wherein each of the first material , the second material , the third material and the fourth material comprises a material selected from the group consisting of a gain material, a dielectric and a metal; and wherein at least one of the first material , the second material , the third material and the fourth material includes a metal; and wherein the acousto-optic device further comprises an optical coupling device configured to guide light (L) incident onto the acousto-optic medium having the multi-layer nanostructure to enable the light to propagate in the second layer , the optical coupling device comprising a prism or a diffraction grating layer disposed on a surface of the acousto-optic medium having the multi-layer nanostructure. <EOS>