PURPOSE: To provide a device which has wavelength selection optical filters including lattice structure arranged within a waveguide layer structure, is made sufficiently wider in the turning range for the given combinations of waveguide layer and material parameters than heretofore and is easily producible.

CONSTITUTION: An active layer 5' of intrinsic i-InGaAsP which induces a refractive index change is grown on, for example, a thick n+InP layer 3' via a buffer layer 4' by epitaxy of the same material as the material of the substrate and the waveguide layer 6' of the n+InP is arranged thereon. The lattices 7' are formed by utilizing the InGaAsP arranged in the layer 6' in such a manner that the lattice periods Λ1 in the lattice regions 1 are larger than the lattice periods Λ2 within the lattice region 2. A resistance region 15 is formed by proton bombardment, etc., in the transition part of both lattice regions 1, 2. Implantation electrodes I1, I2 are selectively implanted from the respective implantation electrodes 11' into the respective lattice regions to make the operation to extract the wavelength selection filters, by which the whole tuning range is made larger by 60 to 80% than the conventional single lattice structure.