OSCILLATION WAVELENGTH SELECTIVE SEMICONDUCTOR LASER DEVICE

PURPOSE: An oscillation wavelength selective semiconductor laser device is provided to select and output light wavelength accurately agreed with a preset WDM(wavelength division multiplex) wavelength in DBR range in no relation to the drive conditions of the laser device. CONSTITUTION: An oscillation wavelength selective semiconductor laser device comprises four areas(4a-4d) consisted of an individual p-electrode and an active layer. One of the four areas is a first reflection area in which continuous diffraction lattice is formed on a light wave guide. One of the four areas is a second reflection area on which periodic diffraction lattice is formed. One of the four areas is a light gain area formed between the first and second reflection areas. The other area of the four areas is a phase correction area formed between the first and second reflection areas.