Wavelength-tunable in-line Fabry-Perot laser with lateral-grating-assisted vertical codirectional coupled filter

We propose a new wavelength-tunable laser structure, in-line Fabry-Perot (IFP) laser with lateral-grating-assisted vertical codirectional coupled filter (LGAVCF). Wavelength tuning is obtained by applying a single tuning current to LGAVCF section of the device. The IFP laser is basically a distributed feedback laser with a novel grating structure that provides ten equally spaced longitudinal modes. The integrated LGAVCF selects one of these modes allowing stable single-mode operation to be achieved. A grating-assisted vertical codirectional coupled filter with periodic changes in width instead of thickness was used to simplify the fabrication process