Fig. 1. Effect of temperature on wavelength of semiconductor laser

Fig. 2. Structure of drive and control system for semiconductor lasers

Fig. 3. Principle of laser drive circuit

Fig. 4. Constant current source circuit

Fig. 5. Schematic of analog switch

Fig. 6. Main program flow

Fig. 7. Semiconductor laser drive control system

Fig. 8. Stability of driving current in semiconductor lasers

Fig. 9. Linearity of driving current of semiconductor laser

Fig. 10. Adjustment time of laser operating temperature

Fig. 11. Operating temperature of laser

Fig. 12. Stability of output power of semiconductor lasers

Fig. 13. Output power of semiconductor laser at 5 ℃，20 ℃ and 35 ℃

Fig. 14. Output power under the constant voltage control mode and the constant power control mode

Fig. 15. Center wavelength under constant voltage control mode and constant power control mode