Method for incidence of light into a photonic crystal optical waveguide
a technology of photonic crystal and optical waveguide, which is applied in the direction of optics, instruments, nanotechnology, etc., can solve the problems of ineffective light entering the crystal, large reflection of the crystal surface, and no highly efficient method of controlling light so as to enter the crystal, etc., to achieve high efficiency, high efficiency, and high efficiency
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Benefits of technology
Problems solved by technology
Method used
Image
Examples
first embodiment
[0043]As the invention, will be described a method of matching wave numbers between the photonic crystal optical waveguide and the outside. FIG. 1 is a concept drawing showing that method.
[0044]Only when the optical wave number in the optical waveguide formed in the photonic crystal matches the wave number of the incident light on the outside does the efficiency of the incident light increase. In other words, as shown in FIG. 2, when the wave number k1 in the wave-guiding mode of the photonic crystal optical waveguide and the wave number k0 of the incident light on the outside of the photonic crystal match the wave number k on the photonic band diagram (wave number matching), the incidence efficiency of light increases. In FIG. 2 the frequency ω is shown along the vertical axis, and the wave number k is shown along the horizontal axis.
[0045]With the equation of motion, the wave number of light corresponds to the momentum. In other words, passing from medium 1 to medium 2 without the...
second embodiment
[0047]Next, as the invention will be described a method of matching the ratio of the electric field to magnetic field of light in the optical waveguide formed in the photonic crystal with the ratio of electric field to magnetic field of the incident light travelling outside the photonic crystal.
[0048]This method is illustrated in FIG. 4. The ratio of electric field to magnetic field (Ex / Hy) of the light in the wave-guide mode of the photonic crystal optical waveguide is matched with the ratio of electric field to magnetic field (Ex / Hy) of the incident light that is travelling on the outside of the photonic crystal.
[0049]The concept of the method according to the present embodiment, is basically the same as the method often performed for electric circuits of matching impedance. However, it differs in that in the case of electric circuits, impedance is stipulated by the ratio of voltage to current (V / I), whereas in an optical waveguide, it is regulated by the ratio of electric field t...
third embodiment
[0053]Next, the method according to the present invention will be described. As shown by Band 1 or Band 2 in FIG. 6C, the value of the intensity ratio of the electric field to magnetic field in the photonic crystal optical waveguide, which is normalized by the intensity ratio of the electric field to magnetic field in a vacuum, may preferably be a positive value of 1 or less. The reason for this will be described below.
[0054]According to the method described in non-patent document 2 (J. Ushida et al., Applied Physics Letters, 82, pgs. 7-9, (2003)), it is seen that by analytically deriving the reflectance of an arbitrary 1-dimensional photonic crystal, the inverse of the intensity ratio of the electric field to magnetic field on the surface of a photonic crystal, which is normalized by the intensity ratio of the electric field to magnetic field in a vacuum, corresponds to the index of refraction that takes into consideration the Fresnel reflection of a photonic crystal.
[0055]Taking t...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More