Control of widely tunable SSG-DBR lasers for dense wavelength division multiplexing

This paper presents a general discussion on the control of widely tunable s uper structure grating distributed Bragg reflector (SSG-DBR) lasers, A feed back control scheme is presented that ensures frequency stability and accur acy (better than +/- 0.5 GHz), as well as high side mode suppression ratio (>35 dB), The active section voltage is monitored to maintain mode stabilit y and a highly stable Fabry-Perot etalon is used as a reference to lock the laser frequency to a specific ITU channel. It is shown that stability can even be maintained when directly modulating the laser at 1.244 Gb/s. Furthe rmore, a characterization scheme is demonstrated that uses the voltage moni toring to generate a look-up table of operation points very efficiently and accurately. For all operation points, the frequency accuracy is better tha n +/- 0.5 GHz and the side mode suppression ratio is above 35 db.