Coherent perfect absorption in one-dimensional photonic crystal with a PT-symmetric defect

In this paper, we demonstrate a one-dimensional photonic crystal defect mode coherent perfect absorber (CPA) or antilasing, which is based on the PT-synthetic material defect. It is found that the CPA can be excited by two coherent monochromatic waves which are located at the frequency range of the defect mode (near the top of the transmission peak in the gap) incident with the same amplitude from both sides. Moreover, we found that the CPA frequency possesses the property of flexible controllability. This property can easily be realized by modulating the variation in thickness of the defect layer and the symmetrical incidence angle of the two coherent beams. Therefore, the photonic crystal defect mode CPA proposed here shows much more flexibility in operation frequency compared with the results in the literature (Chong Y. D. et al., Phys. Rev. Lett., 105 (2010) 053901; Wan W. et al., Science, 331 (2011) 889). Copyright (C) EPLA, 2014