High-order sideband generation in bulk GaAs

When an intense THz field at frequency f(THz) is applied to excitons resonantly created in bulk GaAs by a near infrared laser at frequency f(NIR), sidebands are observed at frequencies f(sideband) = f(NIR) + 2nf(THz), where n is an integer. At temperature T 10 K, sidebands of order -4 <= 2n <= 16 are observed. Sidebands up to 10th order persist at 170 K. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773557]