Nonlinear optical absorption in graphene via two-photon absorption process

Nonlinear optical absorption phenomena in monolayer graphene for scattering between carriers and K-optical phonons are studied via investigating the phonon-assisted cyclotron resonance (PACR) effect. The positions of the PACR peaks are indicated. Only principal transitions make a significant contribution to the optical absorption power. We found that with the increase of the magnetic field, the optical absorption spectrum increases in magnitude and also gives the blue-shift in both one- and two-photon absorption processes. Besides, the half-width is found to be almost independent from the change of temperature, but proportional to the square root of magnetic field, and this agrees with. the previous experimental observations. (C) 2015 Elsevier B.V. All rights reserved.