A high-precision tunable laser control system based on pulse width regulation, wherein through optical power detection and closed-loop control, laser output is monitored in real time, and drive current and optical tuning parameters are dynamically regulated, to achieve precise power and wavelength control;
- nano-scale wavelength resolution and rapid wavelength switching are achieved by combining grating tuning with multi-mode interference filtering and using microelectromechanical system-based dynamical spectral scanning, and wherein the high-precision tunable laser control system comprises:
- a pulse width regulation module, a laser drive module, an optical tuning module, a feedback control module, and a man-machine interaction module, wherein
- the man-machine interaction module is configured to set target wavelength, power and pulse width parameters;
- the pulse width regulation module generates corresponding drive signals according to the settings of the man-machine interaction module;
- the laser drive module excites a laser to output optical signals based on the drive signals;
- the optical tuning module dynamically regulates a laser wavelength to a target value;
- the feedback control module monitors output in real time and performs correction processing;
- the pulse width regulation module comprises a pulse width generation unit, wherein the pulse width generation unit generates the drive signals with tunable pulse width based on preset parameters, and the drive signals are combined with signal modulation and timing control to achieve fine regulation of laser output;
- the optical tuning module comprises a grating tuning unit and a loop compensation unit, wherein the grating tuning unit implements precise spectral range scanning through a microelectromechanical system, and the loop compensation unit is configured to eliminate dynamic errors induced by mechanical regulation;
- the feedback control module comprises a closed-loop control unit, wherein the closed-loop control unit regulates parameters based on detection signals and feeds the regulated parameters back to the laser drive module and the optical tuning module to achieve closed-loop control;
- the closed-loop control unit comprises a control computing processor, wherein the control computing processor computes a regulation angle Δθ of a grating according to the following equation:
- Δ
-
- θ
- =
- arcsin
-
- (
- m
- ·
- Δλ
- d
- +
- sin
-
- θ
- )
- -
- θ
- ;
- wherein m represents a diffraction order, Δλ represents a wavelength deviation, d represents a grating period, and θ represents a current grating diffraction angle;
- the control computing processor computes regulated drive current Inew according to the following equation:
- I
- n
-
- e
-
- w
- =
- I
- c
- ·
- Δ
-
- P
- I
- c
- ·
- η
- -
- Δ
-
- P
- +
- I
- c
- ;
- wherein ΔP represents a power deviation, η represents laser efficiency, and Ic represents current drive current;
- the control computing processor computes regulated pulse width trigger time tnew according to the following equation:
- t
- n
-
- e
-
- w
- =
- t
- c
- 1
- -
- Δ
-
- T
- T
- ;
- wherein tc represents current pulse width trigger time, ΔT represents a pulse width deviation, and T represents a set pulse width.