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Method for regulating two dimensional photon crystal forbidden band

A two-dimensional photonic crystal and bandgap technology, applied in optics, nonlinear optics, instruments, etc., can solve problems such as complex realization, narrow bandgap, and insignificant temperature changes

Inactive Publication Date: 2007-08-15
FUDAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] Some scholars have conducted research in this area before, such as VOLUME83, NUMBER5, and PRL have given the use of liquid crystal materials as a medium to use liquid crystals to change their properties in response to electric fields to achieve the purpose of adjusting the forbidden band position. The band is too narrow and the implementation is complex; the schemes in VOLUME85, NUMBER9, and PRL use the change of temperature to change the properties of the medium. This scheme has the disadvantage that the change of the forbidden band is not significant to the temperature change.

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  • Method for regulating two dimensional photon crystal forbidden band
  • Method for regulating two dimensional photon crystal forbidden band
  • Method for regulating two dimensional photon crystal forbidden band

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Embodiment 1

[0030] In this embodiment, the structure is shown as 31 in Fig. 4 (a), which is a top view of a two-dimensional photonic crystal structure, and air holes are drilled in a square structure on a GaAs (ε=12.9) plate, and the lattice The constant is 0.6mm, the duty cycle f=0.567, and the plasma frequency ω p =0.785THz, add a magnetic field along the direction of air space extension, and the magnetic field strength is from 0-0.474 Tesla. 30 in Fig. 4(a) is a TM wave energy band diagram, and it can be seen that the forbidden band has not changed. 32, 33, and 34 in Figure 4(a) are the energy band diagrams of the TE waves under the conditions of no magnetic field, magnetic field strength 0.24 Tesla, and magnetic field strength 0.474 Tesla, respectively. We can see that the energy band distribution has changed significantly Figure 4(b) is a schematic diagram of the change of the forbidden band. The abscissa is the change of the magnetic field strength, and the vertical axis is the fre...

Embodiment 2

[0032] In the present embodiment, the structure as shown in 41 in Fig. 5 is a top plan view of a two-dimensional photonic crystal structure, and air holes are drilled in a triangular structure on a GaAs (ε=12.9) plate, and the lattice constant is 0.6mm, duty cycle f=0.735, plasma frequency ω p =0.942THz, add a magnetic field along the air space extension direction, 40 in Fig. 5 is the TM wave energy band diagram, it can be seen that the forbidden band has no change, and 42 in Fig. 5 is the energy band diagram of the TE wave without adding a magnetic field , 43 in Figure 5 is a schematic diagram of the change in the forbidden band of the TE wave despite the change of the magnetic field strength. The range of the magnetic field strength is still 0 to 0.474 Tesla. The abscissa is the change of the magnetic field strength, and the ordinate is the frequency. Forbidden bands, we can see that with the increase of the magnetic field strength, the starting frequency of the forbidden ba...

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Abstract

The present invention provides one kind of method for regulating the forbidden band of 2D photon crystal. According to basic theory of photon crystal, semiconductor theory and electromagnetic field theory, applying magnet field can alter the resonant frequency of 2D photon crystal structure to affect the dielectric constant function with frequency of TE wave. For TM propagation state, the dielectric constant function with frequency contains no item of resonant frequency, and this means that it is independent with magnetic field. Therefore, when some magnetic field is applied along the direction of extending 2D photon crystal structure column, the photon crystal structure and thus the forbidden band position and distribution of electromagnetic wave in TE propagation state will be changed and the forbidden band of the 2D photon crystal is regulated.

Description

field of invention [0001] The invention belongs to the technical field of photonic crystals, and in particular relates to a method for adjusting the band gap position of a two-dimensional photonic crystal. Background technique [0002] The present invention is based on photonic crystal theory (seeing Phys.Rev.Lett.58, p.2059, 1987 and J.D.Joannopoulos, R.D.Meade, and J.N.Winn, Photonic Crystals: Molding the Flow of Light (Princeton Univ.Press, NJ, 1995) .). Photonic crystal is a new concept and new material proposed in the late 1980s. Its basic idea is: like electrons in semiconductors, when light or electromagnetic waves propagate in a periodic dielectric structure, due to the influence of the periodic structure, It will also form an energy band structure, that is, a photonic energy band; there may be a band gap between the bands, that is, a photonic band gap, and a periodic dielectric structure with a photonic band gap is a photonic crystal. If the frequency of the light...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G02F1/01
Inventor 许春资剑刘晓晗傅荣堂贾武林韩德专李乙洲
Owner FUDAN UNIV