Tunable DFB Laser And Its Controlling Circuit

Tunable DFB Lasers are one of the key components for optical communication systems and next-generation optical networks.It not only providestimely, effective inventory management and rapid establishment of the channels for the dense wavelength division multiplexing (DWDM) system, thereby greatly reducing the cost of an alternative light source, but also offers automatic wavelength configuration, wavelength conversion and wavelength routing functionfor the next generation reconfigurable optical network, thereby greatly improving the dynamic flexibility and bandwidth utilization. The tunable semiconductor lasers have attracted great attention from both home and abroad with its great prospect for application. In view of research and application of the semiconductor array lasers based on the REC technique in our lab,and to make full advantage of the exceptionally low manufacturing cost brought by REC technique/this paper puts forward a possible solution for high-performance and low-cost tunable lasers,based on REC array laser chips and controlled by a micro step motor.First of all, this paper goes over the history of optical communications and tunable semiconductor lasers, with the final conclusion that high-performance,low-cost tunable lasers hold great potential for application in the fields of optical communications,and will contributesubstantially to the development of this field.Secondly,this paper makes a brief introduction of the DFB laser arrays based on the REC technique, and designs a mechanical tuning module based on our advantageous foundation on the research of the array lasers in the lab. This modules complements wavelength tuning by the method of mounting the optical fiber on the step motor and controlling the movement of the motor to realize wavelength channel selection.Not only that, the design has also been substantiated, and that we complete the whole establishment of the tunable DFB laser module,and its peripheral controlling circuit. Through persistent hardware and software debugging,and trial and error, our goal of mechanical tuning of the 8-channel DFB lasers through the step-motor, and electrical tunning of the single wavelength through temperature controlling is finally reached.The possible solution for tunable lasers put forward in this paper with its low cost holds great potential for application in the future, for the fact that the mechanical tuning proposed can easily have a wide tuning range. Also,with just the designing of the REC laser array of required wavelength, full C-band tuning couldbe achieved.