Summary of the invention
For solving the problem that prior art exists, the present invention provides the drive system of a kind of Distributed Feedback Laser and drives
Dynamic method.The method includes:
Constant-current drive circuit and constant temperature drive circuit, be respectively coupled to described Distributed Feedback Laser;
Master controller, in order to receive an external drive instruction to parse corresponding constant-current control signal and constant temperature control
Signal processed also exports;
D/A converter, couples described constant-current drive circuit, constant temperature drive circuit and master controller, in order to receive
The described constant-current control signal of described master controller output and thermostatic control signal also carry out DA conversion, with life
Become current constant control voltage and thermostatic control voltage and export to described constant-current drive circuit and constant temperature drive circuit;
Wherein, described constant temperature drive circuit and described constant-current drive circuit all use monolithic integrated optical circuit, pass through
The current constant control voltage of D/A converter output and the parameter of thermostatic control Control of Voltage Distributed Feedback Laser, so that
The luminous power that the output of described Distributed Feedback Laser is stable.
Further, in the drive system of described Distributed Feedback Laser, described master controller comprises current constant control
Table and thermostatic control table, it receives after external drive instructs by described current constant control table and thermostatic control table solution
Precipitated phase is answered constant-current control signal and thermostatic control signal and exports.
Further, in the drive system of described Distributed Feedback Laser, described constant-current drive circuit comprises a control
Device processed, in order to be controlled compensation, to stablize described DFB to the Output optical power of described Distributed Feedback Laser
The Output optical power of laser instrument.
Further, in the drive system of described Distributed Feedback Laser, the detection of described constant-current drive circuit is described
The size of Distributed Feedback Laser Output optical power, if beyond a setting threshold value, the most described constant-current drive circuit is automatic
Turn off to protect described Distributed Feedback Laser.
Further, in the drive system of described Distributed Feedback Laser, described constant temperature drive circuit comprises an electricity
Pressure comparator, one end of described voltage comparator accepts described thermostatic control voltage, and the other end receives a setting
Reference voltage, when described thermostatic control electric voltage exception, described voltage comparator export a triggering level with
Automatically shut down described constant-current drive circuit to protect described Distributed Feedback Laser.
The present invention also provides for the driving method of a kind of Distributed Feedback Laser, and the method includes:
Drive system with PC connection Distributed Feedback Laser as according to any one of claim 1 to 5
Master controller;
According to the driving electric current needed for described Distributed Feedback Laser and temperature, described outside is set on described PC
Driving instruction;
Send described external drive by described PC to instruct to described master controller, so that described master controller
Output constant current control signal and thermostatic control signal.
Further, in the drive system of described Distributed Feedback Laser, described PC sends described outside and drives
Before dynamic instruction, described external drive instruction is verified.
Further, in the drive system of described Distributed Feedback Laser, described PC passes through RS232 bus
Connect the master controller of the drive system of described Distributed Feedback Laser.
The constant temperature drive circuit of the drive system of the Distributed Feedback Laser that the present invention provides all is adopted with constant-current drive circuit
With monolithic integrated optical circuit, to build constant-temperature constant-current drive system, it is achieved the laser driving system of high integration
Purpose, the drive system of described Distributed Feedback Laser is simple and is prone to debugging, and easily carries out digital control,
Substantially increase motility and the reliability of system.
Detailed description of the invention
As it is shown in figure 1, the drive system of the Distributed Feedback Laser of the present invention includes master controller 10, DA changes
Device 20, constant-current drive circuit 40 and constant temperature drive circuit 50.During use, constant-current drive circuit 40 and constant temperature drive
Galvanic electricity road 50 couples Distributed Feedback Laser 30.
Master controller 10 instructs and parses corresponding constant-current control signal and thermostatic control in order to accept external drive
Signal.Driving electric current according to Distributed Feedback Laser 30 and temperature can arrange specific constant-current control signal and
Thermostatic control signal is used for controlling to drive electric current and the size of temperature, thus controls the power of laser instrument.For
The setting driving electric current and temperature of Distributed Feedback Laser 30 is all contained in described constant-current control signal and thermostatic control
In signal.Master controller 10 for example, AVR single chip, uses MLF(Micro Lead Frame) mode
Encapsulate to reduce the circuit volume of whole system.
D/A converter 20 is for the constant-current control signal exported by above-mentioned master controller 10 and thermostatic control signal
Carry out DA conversion and control voltage and thermostatic control voltage with output constant current, it is simple to constant-current drive circuit 40 and perseverance
Temperature drive circuit 50 processes.D/A converter, for example, with four-way 16 bit pad of SPI interface, is used
To ensure that output controls the precision of voltage.D/A converter 20 connects master controller 10 by SPI interface.
Constant-current drive circuit 40 and the constant temperature drive circuit 50 of the present invention all use monolithic integrated optical circuit.Described
Constant-current drive circuit 40 is used for the parameter according to current constant control Control of Voltage laser instrument 30 to control laser instrument
Power.Constant-current drive circuit 40 comprises current constant control table, and constant-current drive circuit 40 receives external drive instruction
Corresponding constant-current control signal is parsed afterwards by described current constant control table.
Constant-current drive circuit 40 comprises controller 41, in order to the output light merit to described Distributed Feedback Laser 30
Rate is controlled compensating, with the Output optical power of stable Distributed Feedback Laser 30.Controller 41 can be PID control
Device processed.The threshold value of Distributed Feedback Laser 30 Output optical power also can be pre-set in constant-current drive circuit 40, and
Automatically detecting the Output optical power size of described Distributed Feedback Laser 30, if beyond described threshold value, then constant current is driven
Galvanic electricity road 40 is automatically switched off to protect Distributed Feedback Laser 30.
Described constant temperature drive circuit 50 according to the parameter of thermostatic control Control of Voltage laser instrument 30 to control laser
The power of device.Comprising voltage comparator 51 in constant temperature drive circuit 50, one termination is by described thermostatic control electricity
Pressure, the other end receives the reference voltage of a setting, when described thermostatic control electric voltage exception, described voltage ratio
Relatively device 51 exports a triggering level to automatically shut down described constant-current drive circuit 40 to protect described DFB laser
Device 30.
Refer to the flow chart of the driving method of the Distributed Feedback Laser 30 that Fig. 2, Fig. 2 are the present invention.First use
PC connects the master controller 10 in the Distributed Feedback Laser drive system of the present invention, then according to DFB laser
The demand driving electric current and temperature of device 30 arranges described external drive instruction, and then this external drive instruction is sent out
Deliver to master controller 10, make master controller 10 output constant current control signal and thermostatic control signal.
PC attainable control function is used to include: laser instrument 30 luminous power to be set, laser instrument 30 is set
Temperature, obtain current onboard temperature, obtain current lasers 30 driving electric current, turn off laser instrument 30
Constant-current driving, shutoff laser instrument 30 constant temperature drive.
The luminous power of described laser instrument 30 and the setting of temperature are all to send instruction, master controller 10 by serial ports
Control D/A converter 20 output constant current and thermostatic control voltage after receiving instruction, thus reach to arrange mesh
's.
The transmission of instruction is all to pass through CRC check, it is ensured that the correctness of data, slave computer tries again simultaneously
Judge, to improve reliability to greatest extent, it is to avoid send error code and cause errored response but laser instrument 30
The power or the temperature that arrange are too high.
The constant current of described shutoff laser instrument 30 and constant temperature drive the form being also to be sent instruction by serial ports, flow process one
Sample.Obtain onboard temperature be then by AD sample onboard temperature survey chip obtain temperature data (institute
Stating onboard temperature survey chip is to simulate integrated chip, and temperature transition becomes voltage, and different temperature correspondences is not
Same voltage, has the relation mapped one by one).
The electric current that drives obtaining laser instrument 30 is then to judge current driving electricity by the size of sampling driving voltage
The size of stream, thus monitoring laser 30 in real time, it is to avoid the infringement that laser instrument is caused by stream or overvoltage excessively.
Constant-current drive circuit 40 and the constant temperature drive circuit 50 of the present invention all use monolithic integrated optical circuit.Preferably
Ground, can use chip ADN2841 as constant-current drive circuit 40, and ADN8831 is as constant temperature drive circuit
50。
Seeing the data book of chip ADN2841, the LD of laser instrument 30 connects the bias current control of chip
End IBIAS processed, the backlight detector of laser instrument 30 connects IMPD end, D/A converter 20 connecting laser
Power setting end PSET, warning arrange end ASET.The backlight test side detection laser output of chip
It is whether the value that arranges of expection, is then controlled compensation by internal PID control circuit, so that laser
The output of device 30 reaches stationary value.Further, described D/A converter one end can be used to arrange report
The size of alert electric current, sends out a pulse and is controlled automatically shutting down of chip to ALS end after going beyond the scope, from
And laser instrument is unlikely to damage in the case of being effectively guaranteed stream.
See the data book of ADN8831, after the temperature value that described external drive instructs is set, temperature control
Voltage processed produces pressure reduction between THERMIN and TEMPSET, and difference signal is sent into chip internal and amplified
Device is amplified, and then by internal PID control circuit, finally the triggering signal as PWM temperature control touches
Send out PWM work, control the TEC circuit (not marking in figure) within laser instrument 30 and carry out laser instrument 30
Heating or refrigeration, thus affect critesistor resistance, allow outside bridge circuit reach balance, i.e. complete
Temperature control controls process.The thermostatic control voltage of D/A converter 20 output enters the voltage input of ADN8831
End, is simultaneously connected with one end of voltage comparator 51 input, and the other end of voltage comparator 51 input arranges one
Reference voltage.When D/A converter 20 output voltage exception, comparator 51 exports a triggering level, this
Triggering level is connected to the unlatching of ADN8830 and controls end SD, thus controls it and open or close, and then
Protect the TEC semiconductor cooler (not marking in figure) within Distributed Feedback Laser 30.ADN8831 manages
Temperature control precision in opinion is 0.01 DEG C, corresponding 0.01 DEG C of the every 250 μ V of difference voltage of 2,4 pins.
Output voltage and the relational expression arranged between temperature of D/A converter 20 are
TEMPSET=-0.025 (T-25)+1.397, T are the temperature arranged.Great temperature is set, refers to not
With laser instrument service manual, the corresponding relation of temperature when laser instrument is tested and centre wavelength can be provided above,
Test temperature is optimum working temperature to be arranged, and does not repeats them here.
The drive system of the Distributed Feedback Laser that the present invention provides is driven by two panels integrated circuit member constant-temperature constant-current
System, for the laser driving system of high integration, simple and be prone to debugging, it is also easy to carry out numeral control
System, substantially increases motility and the reliability of system.Overcome the PID controller that discrete device is built
Carry out automated power control (APC) and automatic temperature-adjusting controls the circuit complexity that (ATC) brings, error-prone,
And the inconvenience such as the extremely difficult adjustment of pid control parameter.
Obviously, those skilled in the art can carry out various change and modification without deviating from the present invention to invention
Spirit and scope.So, if the present invention these amendment and modification belong to the claims in the present invention and
Within the scope of equivalent technologies, then the present invention is also intended to change and including modification include these.