Ultrafast All-Optical Light Control with Tamm Plasmons in Photonic Nanostructures

Ultrafast all-optical modulators are crucial parts of prospective photonic devices. A number of plasmonic and dielectric nanostructures were nominated as candidates for integrated all-optical circuits. The key principle in the design of such devices is to engineer artificial optical resonances to increase the magnitude of modulation or to change the characteristic switching time. The major drawback is that the manufacturing becomes rather sophisticated. Here, we propose a method to tailor the ultrafast response of photonic crystal–metal nanostructures by employing a spectral shift of the Tamm-plasmon resonance. We show that for the absorbed pump fluence of 6 pJ reflectance of the sample at the near-infrared probe wavelength in the vicinity of the Tamm-plasmon resonance changes 25× stronger as compared with a bare metal film. Additionally, we show that by choosing a proper wavelength around the resonance a background-free reflectance modulation can be achieved. The characteristic pulse-limited switching time, in this case, is 150 fs.