Fen-Ying Li

Bio: Fen-Ying Li is an academic researcher from Nanjing University of Posts and Telecommunications. The author has contributed to research in topics: Dielectric & Kerr effect. The author has an hindex of 1, co-authored 1 publications receiving 5 citations.

The asymmetric optical bistability based on the one-dimensional photonic crystals composed of the defect layers containing the magnetized ferrite and nonlinear Kerr dielectric under the transverse electric polarization

Abstract: Utilizing the modified transfer matrix method, under transverse electric polarization, asymmetric optical bistability is achieved by designing one-dimensional photonic crystals (PCs) with two Bragg reflector segments containing traditional dielectrics and asymmetric defect multilayers consisting of a magnetized ferrite and nonlinear Kerr dielectric. When the incident wave frequency equals the resonance frequency, owing to the breaking of symmetry in the defect layers and the Voigt magneto-optical effect generating in the magnetized ferrite layers together with the Kerr effect existing in the Kerr dielectric layers, the asymmetric optical modulations are presented as the bistable state in the forward propagation and the multistable state in the backward propagation. Also, the diverse energy localization distributions of the electric field in the proposed PCs from the two incident directions are graphically illustrated. Furthermore, the optical bistable switch-up and switch-down thresholds of the proposed resonator can be tailored flexibly by the external magnetic field, the incident angle, the thicknesses of different dielectrics, and the nonlinear coefficient of Kerr dielectric. This work provides a constructive proposal for the design of light modulators, such as the optical isolator, the optical triode, the all-optical diode, and the sensor.

Wide-angle polarization selectivity based on anomalous defect mode in photonic crystal containing hyperbolic metamaterials.

Abstract: Conventional defect modes in all-dielectric 1D photonic crystals (PCs) are polarization-insensitive. This poses a great challenge in achieving high-performance polarization selectivity. In this Letter, we introduce a defect layer into a 1D PC containing hyperbolic metamaterials to achieve an anomalous defect mode with polarization-sensitive characteristics. As the incident angle increases, such a defect mode remains almost unshifted under transverse magnetic polarization, while strongly shifting toward shorter wavelengths under transverse electric polarization. The polarization-sensitive characteristics of the defect mode can be well explained by the Fabry-Perot resonance condition. Assisted by the polarization-sensitive defect mode, wide-angle polarization selectivity with an operating angle width up to 54.8° can be realized. Our work provides a route to designing wide-angle linear polarizers using simple 1D structures, which would be useful in liquid crystal display and Q-switched lasers.

Bistable absorption in a 1D photonic crystal with a nanocomposite defect layer.

Abstract: We investigate the nonlinear absorption properties of a defective one-dimensional photonic crystal at the near-infrared range using the nonlinear transfer matrix method. The defect is a nanocomposite layer containing vanadium dioxide nanoparticles sandwiched between two nonlinear dielectric layers. The linear absorption spectrum of the designed structure has three resonant absorption lines at the bandgap region of the photonic crystal. We can reconfigure the structure in the linear regime from nearly transparent to absorbent or vice versa in multiple resonant wavelengths by adjusting the temperature. Moreover, the system shows absorptive bistability by adjusting the intensity and incident angle of the input light. We discuss the tunability of the nonlinear absorption in detail. In the nonlinear regime, we show that, besides the temperature, the structure can be reconfigured from absorbent to transparent and vice versa by adjusting the incident optical power and the incident angle. We validate the results by examining the electric field distribution throughout the structure.