Fig. 2
From: Self-induced transparency in a perfectly absorbing chiral second-harmonic generator
Experimental observation of self-induced transparency in a one-port perfect absorber. (a) Experimentally measured transmission spectra of the input pump (blue) and its SHG (red) at various pump power. Self-induced transparency manifests itself at the higher pumping (bottom), in contrast to the perfect absorption state at the lower pumping (top). The corresponding transmission rate of the input pump (b) and the SHG power (c) are measured with respect to the pump power, both exhibit quadratic dependences due to the second-order nonlinearity