High Stability Of Erbium Doped Superfluorescent Fiber Source Based On Automatic Temperature Control System

Amplified spontaneous emission (ASE) light source has the advantages of outputstability, wide and flat spectrum. Erbium-doped fiber source can be widely used inoptical fiber communication and optical fiber sensing. Most previous studies focused onthe width and flatness of the spectrum. When the light source is used in the fiber sensorsystem, the stablity of ASE light source output power plays a crucial role to the sensors.The stability of ASE light source is mainly determined by the pump laser.ASE light source ouput power and spectrum are affected by many factors. Themain research in this paper focuses on the stablity of ASE light source. First, this paperintroduces the basic theory of amplified spontaneous emission and then analyses theamplified spontaneous emission principle and discusses transition characteristics ofErbium-doped fiber of erbium ions. At the same time, it introduces the source of fourstructures and specifically describes the role of each passive and active device used inthe system as a whole.Secondly, this paper mainly studies the structure of the C-band ASE light source,analyses the effects of Erbium-doped fiber length and pump power on output spectrum.Using the gain flattening filters can flat the output spectrum. We describe the mainstructure of C-band erbium-doped fiber based broadband ASE source and thencompares the double way forward and backward structure. Ananlyses the effects ofdifferent structure on output optical power output spectrum.Finally, the article analyses the stability of the system as a whole. As a pumpsource, the stability of semiconductor lasers is critical for a system. While Laser drivingcurrent stability and internal temperature stability determines the laser itself. This articledesigns a constant-current driving circuit for laser. The laser can be drived with constantcircuit. In the aspect of temperature control, the internal temperature is controlled bytemperature control chips through controlling the current of the TEC cooler, so as tomaintain a constant temperature inside the laser. Thus makes the entire ASE light sourcesystems stable with constant output power.