Fig. 1. Block diagram of temperature control system

Fig. 2. Temperature detection circuit

Fig. 3. Error amplifying circuit

Fig. 4. PID compensation circuit

Fig. 5. TEC drive circuit diagram

Fig. 6. TEC drive simulation circuit diagram

Fig. 7. LD temperature monitoring circuit diagram

Fig. 8. Test block diagram of DFB laser temperature control system

Fig. 9. Photo of temperature test verification platform

Fig. 10. Three-temperature data curve of 5 LDs

Fig. 11. Three-temperature optical power curve of 5 LDs