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 IR 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 {greater than or equal to} 2n {greater than or equal to} 16 are observed. Sidebands up to 10th order persist at 170 K. 
Benjamin Zaks, Hunter Banks and Mark S. Sherwin
cond-mat.mes-hall cond-mat.mtrl-sci physics.optics