GRATING-ASSISTED CODIRECTIONAL VERTICAL COUPLER TUNABLE OPTICAL FILTER

摘要

PURPOSE: A wavelength tunable optical filter of a grating-assisted codirectional coupler type is provided to improve crosstalk between neighboring WDM(wavelength division multiplexing) communication channels by obtaining a waveform with side lobe removed. CONSTITUTION: A first InGaAsP waveguide layer is prepared on an n-type InP substrate. An n-type InGaAsP lattice layer is prepared on the first InGaAsP waveguide layer. An n-type InP layer is prepared on the n-type InGaAsP lattice layer. A second p-type InGaAsP waveguide is prepared on the n-type InGaAsP lattice layer. A p-type InGaAsP clad layer is prepared on the second p-type InGaAsP waveguide.