WAVELENGTH VARIABLE OPTICAL MULTIPLEXER AND DEMULTIPLEXER

摘要

PURPOSE:To switch route for propagating light signals of an arbitrary wavelength at a high speed by providing diffraction gratings to the crossing region of two crossed waveguides and varying the refractive index of this crossing region, thereby varying multiplexing and demultiplexing wavelengths. CONSTITUTION:The two ridge waveguides 14, 15 consisting of p-InP layer 13 are crossed and formed on an InGaAsP waveguide layer 12 on an n-InP substrate 11. The diffraction gratings 17 is formed along the layer 12 symmetrically with the respective waveguides 14 and 15 in this crossing region 16. Electrodes 18, 19 on a p side and n side are respectively provided on the front and rear faces of the region 16. A carrier is injected or electric field is impressed on the waveguide layer 20 (the layer 12 in the part of the region 16) by forward biasing or reverse biasing, by which the refractive index can be changed. The central wavelength of the multiplexing and demultiplexing waves is thereby varied and the routes for propagating the the light signals of the arbitrary wavelength are switched at the high speed.