We have studied the phenomenon of two-photon absorption in photonic nanowires doped with an ensemble of four-level nanoparticles. The photonic nanowire is made from two photonic crystals, A and B, where A is embedded in B. Photons are confined in the nanowire due to the band structure engineering of photonic crystals. It is considered that one of the resonance levels of nanoparticles lies near a photon-bound state of the nanowire. The two-photon absorption coefficient has been calculated using the time-dependent Schrödinger equation. It is found that there is an inhibition of two-photon absorption in the system. This is due to the strong coupling between nanoparticles and the nanowire.
We study the two-photon switching mechanism in photonic crystal nanowires doped with an ensemble of nanoparticles. Nanowires are made from embedding one crystal into another. The energy spectrum of the embedded crystal is higher than that of the outer photonic crystal. The nanoparticles are interacting with bound states and with each other. The photon absorption coefficients have been calculated in the presence of a probe and a pump laser fields. Two transparent and absorption states are found. We anticipate that the present research can be used to make new types of all-photonic devices.