Two-dimensional photor crystal polarization beam dividing device

Abstract

The planar photon crystal bundle-dispersing polarimeter refers to the field of electromagnetic wave bundle-dispersing polarimeter. Its character is that insert the dielectric stick to the background media whose refractive index is much lower than that of the dielectric stick to form a planar seasonal structure. Along the incident direction of the electromagnetic wave, it's orderly composed of three parts that are the left transmission-enhancing film, the main part and the right transmission-enhancing film. The radius of the dielectric stick in the main part is higher than that of the other two parts. The incident side of the main part is pressed close to the outdiffusing side of the left transmission-enhancing film, and the incident side of the right transmission-enhancing film is pressed close to the side of the outdiffusing side of the main part. This invention has an advantage that the fixity of all the standards of the photon crystal itself won't metamorphose. When the work wavelength is the same, the crystal lattice constant of this invention is much smaller than that of the present planar photon crystal bundle-dispersing polarimeter. Therefore it's portable and cabinet. This invention can also transmit two reciprocally vertical polarizing ponderance at the same time, so it's polarizing degree is high and the transmitted index is big.

Description

[0001] Technical field: The present invention relates to an electromagnetic wave polarization beam splitter, specifically a two-dimensional photonic crystal polarization beam splitter. Background technique: [0002] Photonic crystal is a dielectric structure with periodicity in space, while two-dimensional photonic crystal is a dielectric structure with periodicity in two-dimensional plane. When electromagnetic waves propagate, they are generally unpolarized, that is, they have two mutually perpendicular polarization components that are not equal to zero. A polarizing beam splitter is a device that decomposes an incident unpolarized electromagnetic wave into two beams of electromagnetic waves with different polarizations. When an electromagnetic wave propagates in a two-dimensional photonic crystal, it can be decomposed into two polarization components parallel to and perpendicular to the axis of the two-dimensional plane, called P and S waves. [0003] Chinese Patent No. 9811...

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Problems solved by technology

[0006] 1. For a certain working wavelength, the appearance of the band gap requires that its lattice constant is comparable to the wavelength, or even larger than the wavelength. For the two-dimensional photonic crystal polarizers in the above two articles, its λ / a, that is, the working wavelength and the crystal The ratio of the lattice constant is about 5:1 to 1:1, so its volume is limited and cannot be made small, especially if the working wavelength is in the microwave to radio frequency band, the volume of the polarizer will be quite large, which is not conducive to integration optical requirements

[0007] 2. Since one polarized component must be reflected, it cannot meet the requirement of transmitting both polarized waves in specific occasions

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