Ultrahigh-resolution photonic-crystal superprism and method for designing the same

Patent metadata

Field	Value
Publication number	US-10274642-B2
Application number	US-201515301505-A
Country	US
Kind code	B2
Filing date	Feb 4, 2015
Priority date	Apr 1, 2014
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

A method for designing an ultrahigh-resolution photonic-crystal superprism, including the following steps: selecting a medium material, and determining a structure type and parameter of a photonic crystal, obtaining the photonic crystal's equifrequency graph, and looking for an auto-collimation area; obtaining the group velocity distribution of points in the equifrequency graph, and looking for a low group velocity area; optimizing the photonic crystal's structure parameter, facilitating the auto-collimation and the low group velocity area in the photonic crystal's equifrequency graph to be overlapped as much as possible, and defining overlapping area as a work area; obtaining an equal incidence-angle line, rotating the photonic crystal to intersect the equal incidence-angle line with the work area, and selecting the appropriate incidence angle in an intersection point to complete the design of the photonic-crystal superprism. When light makes incidence via the above incidence angle, the photonic crystal may separate light with different frequencies significantly.

First claim

What is claimed is:

1. A method for designing an ultrahigh-resolution photonic-crystal superprism, wherein the method comprises at least the following steps:
Step S 1 : selecting a medium material, and determining a structure type and a structure parameter of a photonic crystal;
Step S 2 : obtaining an equifrequency graph of the photonic crystal, and looking for an auto-collimation area in the equifrequency graph;
Step S 3 : obtaining the group velocity distribution of each point in the equifrequency graph, and looking for a low group velocity area;
Step S 4 , optimizing the structure parameter of the photonic crystal, facilitating the auto-collimation area and the low group velocity area in the equifrequency graph of the photonic crystal to be overlapped as much as possible, and defining the overlapping area as a work area;
Step S 5 : obtaining an equal incidence-angle line, rotating the photonic crystal to intersect the equal incidence-angle line with the work area, and selecting the appropriate incidence angle in an intersection point to complete the design of the photonic-crystal superprism.

2. The method for designing the ultrahigh-resolution photonic-crystal superprism according to claim 1 , wherein the medium material is selected from at least one of silicon, silicon dioxide, germanium, gallium arsenide and gallium nitride.

3. The method for designing the ultrahigh-resolution photonic-crystal superprism according to claim 1 , wherein the structure type comprises a two-dimensional structure or a three-dimensional structure.

4. The method for designing the ultrahigh-resolution photonic-crystal superprism according to claim 1 , wherein the structure type comprises a porous structure or a medium column structure.

5. The method for designing the ultrahigh-resolution photonic-crystal superprism according to claim 1 , wherein the structure type comprises a square-lattice primitive-cell structure, a rectangular-lattice primitive-cell structure, a triangular-lattice primitive-cell structure or a hexagonal-lattice primitive-cell structure.

6. The method for designing the ultrahigh-resolution photonic-crystal superprism according to claim 1 , wherein in Step S 4 , the structure parameter comprises filling ratio, the constant term of a lattice, as well as the thickness and the length of a photonic crystal, at least one of which is changed to optimize.

7. The method for designing the ultrahigh-resolution photonic-crystal superprism according to claim 1 , wherein the auto-collimation area comprises an auto-collimation area passing through the entire Brillouin area or a local auto-collimation area.

8. The method for designing the ultrahigh-resolution photonic-crystal superprism according to claim 1 , wherein the auto-collimation area comprises a strict auto-collimation area and an adjacent approximate auto-collimation area thereof.

9. The method for designing the ultrahigh-resolution photonic-crystal superprism according to claim 1 , wherein the low group velocity is that the group velocity of light propagating in the photonic crystal is less than 3E7 meter/second.

10. The method for designing the ultrahigh-resolution photonic-crystal superprism according to claim 1 , wherein the equifrequency graph, the group velocity and the equal incidence-angle line are obtained by theoretical calculation or by an experimental means.

11. A photonic-crystal superprism, wherein an auto-collimation area and a low group velocity area in an equifrequency graph of the photonic crystal superprism are overlapped, and an equal incidence angle thereof is intersected with the overlapped area.

12. The photonic-crystal superprism according to claim 11 , wherein the photonic-crystal superprism is a porous structure or a medium column structure.

Assignees

• Shanghai Inst Microsystem & Information Tech Cas
• Univ Fudan

Inventors

• Jiang Xunya
• Li Wei
• Zhang Xiaogang
• Lin Xulin

Classifications

• G02B27/0012

  Optical design, e.g. procedures, algorithms, optimisation routines · CPC title

• G02B27/1006

  for splitting or combining different wavelengths (G02B27/1086, G02B27/141 take precedence) · CPC title

• G02B27/126

  The splitting element being a prism or prismatic array, including systems based on total internal reflection · CPC title

• G02B1/005 Primary

  made of photonic crystals or photonic band gap materials (photonic band-gap structures or photonic lattices in integrated optics G02B6/1225; photonic band-gap structures or photonic lattices in optical fibres G02B6/02295) · CPC title