Drive For Chaotic Semiconductor Laser And Temperature Control System Design

Chaotic laser is a special output form of laser,which is mainly realized by external optical feedback.However,the external optical feedback device has complex structure,unstable output and easy to be affected by the external environment and working parameters.In order to overcome the above problems,this research group integrated all the devices and developed a low-cost,practical,convenient and stable output chaotic semiconductor laser.Chaotic semiconductor laser is a power consuming active device,the output characteristics of which are obviously affected by the fluctuation of operating temperature and driving current.Therefore,the development of high precision and high stability of the driving and temperature control system is of great significance to improve the output characteristics of chaotic semiconductor lasers.In this paper,a four-way drive circuit and a one-way temperature control circuit for BOXencapsulated chaotic semiconductor laser are designed.A two-channel drive circuit and temperature control circuit for butterfly encapsulated chaotic semiconductor laser are designed.Specific research contents are as follows:(1)Based on the integrated chip ADN8810 and ADN8835,the drive and temperature control system for the BOX-encapsulated chaotic semiconductor laser is designed.A four-way drive system is designed based on ADN8810 integrated chip.By improving the circuit parameters,the output current could reach a maximum of 200 m A.High precision resistor is selected to compensate the system error caused by the voltage regulator chip,which effectively improved the stability of the system.The temperature control system is designed based on ADN8835 integrated chip.The stable high-precision digital-to-analog Converter(DAC)is used to replace the voltage division to provide the driving voltage for the chip.The high precision and high stability temperature control is realized.The maximum cooling and heating voltage and the maximum cooling and heating current at both ends of the semiconductor cooler can be effectively adjusted to ensure the safe operation of TEC.The experimental results show that the output current stability of the four-way drive circuit for the BOX-encapsulated chaotic semiconductor laser is 0.0108%,0.0067%,0.0056% and 0.0017% in 120 min,respectively,and the temperature control stability is better than 0.003%.(2)The drive and temperature control system for butterfly encapsulated chaotic semiconductor laser is designed based on operational amplifier and field effect tube.A twochannel drive system is designed based on operational amplifier and other components.The driving source 1 uses the current parallel negative feedback circuit to convert the input voltage signal into the current signal that satisfies a certain relationship with it,so as to achieve constant current output.The driving source 2 utilizes the characteristic that the source voltage and drain current are linear when the drain voltage is constant in the field effect tube to realize the linear regulation of the output current.Design temperature control system based on field effect tube and other components.Fuzzy adaptive proportional-integral-differential(PID)algorithm is used to adjust the system parameters in real time and effectively improve the temperature control range of the system.Based on incremental PID algorithm and H bridge circuit to control the current size and direction of TEC,the system temperature control without "dead zone" is realized.The experimental results show that the current accuracy of driving source 1 and 2 is0.01 m A,and the current stability within 120 min is better than 0.0020% and 0.0040%,respectively.The output current of driving source 1 is up to 40.00 m A,and the servo voltage at the output end is 7V.The maximum output current of drive source 2 is 100.00 m A,and the servo voltage at the output end is 7V.The temperature control range of the temperature control system is 15.0??44.0?,the temperature fluctuation of the laser temperature within 120 min is±0.1?,and the wavelength drift of the laser center is only 0.007 nm.