Application of DFB lasers with individually chirped gratings

Continuously and arbitrarily chirped distributed feedback (DFB) gratings of ultrahigh spatial precision for photonic components are implemented using bent waveguides on homogeneous grating fields. Choosing special bending functions, individual chirping functions and distributed phase shifts (PSs) are generated. Thus, additional degrees of freedom are obtained to tailor and improve specific device performances. This paper focuses on bending function design with respect to PS region extension, PS amount, bending radii, maximum tilt angles, threshold gain, photon density profile homogenization and side mode suppression ratio (SMSR). Continuously distributed PSs were implemented in DFB lasers revealing in the experiment reduced photon pile-ups, higher single axial mode stability, higher SMSR and higher yield than conventional abruptly phase-shifted (PS'ed) lasers. Second, multiple-section DFB lasers are implemented showing 5.5 nm wavelength tuning.