• Acta Physica Sinica
  • Vol. 69, Issue 18, 20200443 (2020)
Ouyang Hao1、2、3, Hu Si-Yang1, Shen Man-Ling1、2、3, Zhang Chen-Xi1, Cheng Xiang-Ai1、2、3, and Jiang Tian2、*
Author Affiliations
  • 1College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China
  • 2State Key Laboratory of Pulsed Power Laser Technology, Changsha 410073, China
  • 3Hunan Provincial Key Laboratory of High Energy Laser Technology, Changsha 410073, China
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    Abstract

    Germanium diselenide (GeSe2), a layered IV-VI semiconductor, has an in-plane anisotropic structure and a wide band gap, exhibiting unique optical, electrical, and thermal properties. In this paper, polarization axis Raman spectrum and linear absorption spectrum are used to characterize the crystal axis orientation and energy band characteristics of GeSe2 flake, respectively. Based on the results, a micro-domain I scan system is used to study the optical nonlinear absorption mechanism of GeSe2 near the resonance band. The results show that the nonlinear absorption mechanism in GeSe2 is a superposition of saturation absorption and excited state absorption, and is strongly dependent on the polarization and wavelength of incident light. Under near-resonance excitation (450 nm), the excited state absorption is more greatly dependent on polarization. With different polarizations of incident light, the modulation depth can be changed from 4.6% to 9.9%; for non-resonant excitation (400 nm), the modulation depth only changes from 7.0% to 9.7%. At the same time, compared with saturation absorption, the polarization-dependent excited state absorption is greatly affected by the distance away from the resonance excitation wavelength.
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    Hao Ouyang, Si-Yang Hu, Man-Ling Shen, Chen-Xi Zhang, Xiang-Ai Cheng, Tian Jiang. Polarization-dependent nonlinear optical response in GeSe2[J]. Acta Physica Sinica, 2020, 69(18): 184212-1
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    Received: Mar. 25, 2020
    Accepted: --
    Posted: Jan. 5, 2021
    Published Online: Jan. 5, 2021
    The Author Email: Ouyang Hao (nudtouyanghao@163.com), Hu Si-Yang (husiyang1108@163.com)