Devices, methods, and techniques for frequency-dependent optical switching are provided. In one embodiment, a device includes a substrate, a first and a second optical-field confining structures located on the substrate, and a quantum structure disposed between the first and the second optical-field confining structures. The first optical-field confining structure may include a surface to receive photons. The second optical-field confining structure may be spaced apart from the first optical-field confining structure. The first and the second optical-field confining structures may be configured to substantially confine therebetween an optical field of the photons.