Optical switch

A polarization insensitive optical part comprising a crossing optical waveguide with a reflecting structure that is an m×n optical waveguide including a first group of (m) optical waveguides each having a parallel optical axis, and a second group of (n) optical waveguides each having a parallel optical axis and crossing the first group of optical waveguides at a crossing point, the crossing optical waveguide having a slit that can switch optical signals from the first group of optical waveguides to the second group of optical waveguides, said slit diagonally cutting the crossing point between said first group of optical waveguides and said second group of optical waveguides, a center line of said slit is formed on a bisector of an interior angle between center lines of said first and second optical waveguides, cores of the first and second groups of waveguides having a refractive index equivalent to that of glass, the slit having its interior filled with air during reflection,

• wherein an intersecting angle between an optical axis of said first group of optical waveguides and an optical axis of said second group of optical waveguides (2ø) has a value at which the Goos-Hänchen shift distance (xg(p)) measured when P-polarization light is incident as determined by the following Equation (1) is equal to the Goos-Hänchen shift distance (xg(s)) measured when S-polarization light is incident as determined by the following Equation (3), or a value close to the value:
• x g ⁡ ( p ) = 1 k 0 ⁢ ( k 1 ⁢ z k 0 ) 2 - n 2 2 ⁢ ( k 1 ⁢ z 2 k 1 2 + k 1 ⁢ z 2 k 2 2 - 1 ) ( 1 )
• wherein K1z is shown by the following equation:
• k1z=k1 sin(90−φ) (2) x g ⁡ ( s ) = 1 k 0 ⁢ ( k 1 ⁢ z k 0 ) 2 - n 2 2 ( 3 )
• where k0 denotes a wave number in the vacuum, k1 denotes a wave number in each of the cores of said first and second groups of optical waveguides, k2 denotes a wave number in said slit, k1z denotes a z-axis component of the wave number in said core, ø denotes an intersecting angle between the optical waveguide and the reflection walls on both sides of said slit, and n2 denotes the refractive index in the interior of said reflective structure during reflection.

An optical switch, comprising:

• first and second optical waveguides arranged to intersect each other at a crossing point, the first and second waveguides each having a core and a center line;
• a slit extending diagonally through the crossing point and having first and second side walls arranged opposed to each other, the slit having a central axis that coincides with a bisector of an interior angle between the center lines of the first and second optical waveguides;
• and
• means for arranging an optical transmitting substance and an optical reflecting substance in the slit at the crossing point;
• whereby, when the optical transmitting substance is arranged in the slit at the crossing point, light inputted to the first and second optical waveguides is outputted by the first and second optical waveguides, respectively, and when the optical reflecting substance is arranged at the crossing point, light inputted to the first optical waveguides is reflected on the first side wall of the slit into the second waveguide and is outputted by the second waveguide and light inputted to the second optical waveguide is reflected on the second side wall of the slit into the first waveguide and is outputted by the first waveguide.