Patent ID: 7123789

Claim:
Optical wavelength selective filter realized on an optical waveguide, said filter being able to transmit a first predetermined band of wavelengths (PB′) and to reflect a second predetermined band (SB′) and comprising a plurality of transmissive couples providing said first predetermined band and a plurality of reflective couples providing said second predetermined band disposed in series to each other, each transmissive couple and each reflective couple comprising a first zone with a high refractive index and a second zone with a low refractive index adjacent to each other in a way to form a structure with high gap modulated refractive index, the structure comprising a first substructure and a second substructure in the direction of propagation of the light, wherein the first substructure comprises at least a first and a second transmissive couple in the direction of propagation of the light, the width of the zone with high refractive index of the second transmissive couple being higher than the width of the zone with high refractive index of the first transmissive couple.