Patent ID: 8811823

Claim:
An optical device for the transmission of optical signals of different wavelengths from a single source to a plurality of receiving channels, comprising: at least two major surfaces, a first surface and a second surface delimiting a medium wherein the medium between the surfaces is composed of light-transparent material having a constant refractive index; a first grating (G 1 ) and a second different grating (G 2 ), stationary with respect to each other, each having an X-axis and a Y-axis, located on at least one of the major surfaces, at a constant distance from each other, wherein the two gratings are invariant in the Y-axis and solely dependent on the X-axis, each of the gratings, having a lateral dimension, with at least one sequence of a plurality of parallel lines, wherein the spacing between the lines of the first grating (G 1 ) gradually increases in a direction away from an edge of the grating up to a maximum distance, and wherein the spacing between the parallel lines of the second grating (G 2 ) increases in the same direction as the spacing of the first grating; a light source emitting light waves in a given spectral range, at least a first light wave ( 101 ) having a first wavelength and a second light wave ( 102 ) having a second wavelength, different from the wavelength of the first light wave ( 101 ) emanating from the light source, impinging on the first grating (G 1 ) as plane waves in the same direction, the first and second light waves ( 101 , 102 ) diffracted by the first grating (G 1 ), and subsequently diffracted as output plane waves by the second grating (G 2 ), the first and second light waves ( 101 , 102 ) impinging on the first grating at different portions along the X-axis being diffracted by the first grating (G 1 ) in different directions toward the second grating, and traverse the second grating (G 2 ), the diffracted first light wave ( 101 ) and second light wave ( 102 ) being diffracted respectively by the second grating in a first output direction and a second output direction, wherein the first and second output directions are different and directed to two receiving channels ( 35 ).