Extended tuning range in sampled grating DBR lasers

The authors demonstrate, for the first time, successful implementation of a distributed Bragg reflector laser with two sampled grating mirrors, which they previously predicted should give tuning range in excess of 50 nm. This device uses a uniform grating pitch throughout the structure, and relies on the same fabrication technology as a standard DBR laser. Initial results show 57 nm of mathematical tuning at 1.475 μm with side-mode suppression ratio (SMSR)>30 dB over much of the tuning range. The observed change in operating wavelength versus mirror currents along with below threshold spectra agree with theoretical expectations