Laser light output control mainly uses GATE signal to control light output; The specific frequency, power and other parameters of the light output are controlled by PWM signal, mainly changing the frequency cycle and duty cycle in PWM.
Duty cycle: the ratio of the time for holding high level in the output PWM signal to the time of the PWM clock cycle.
For example, if the frequency of a PWM is 50KHZ, its clock cycle is 20 μ s. If the time of high level occurrence is 6 μ s. Then the low level time must be 14 μ s. Then the duty cycle is 6:20, that is, the PWM duty cycle is 3:10.
At a certain frequency value, when the high level of the laser PWM signal is 1us, the corresponding ADJUST=100%, representing the maximum power, the minimum optical pulse width, and the maximum peak power at that frequency. Increase the high level pulse width (that is, decrease the ADJUST value), and the average laser power decreases and the optical pulse width increases; The frequency, power and pulse width of the optical pulse can be controlled by the frequency and duty ratio of the PWM signal (the signal driven to Q).
1. GATE control mode
When the laser is under the control of GATE mode, only one shield wire of BNC interface needs to be connected to the GATE interface, and the other end needs to be connected to the corresponding interface of the upper computer to realize the laser control. At this time, the user cannot select the QS-EXT mode, otherwise the laser will not emit light.
When the GATE signal interface is suspended or at low power level, the laser can emit light, and other states are very weak indicator light; In this mode, the current, frequency and PWM (pulse width modulation) of the laser are provided inside the laser power supply control box, and the parameters can be changed on the front panel.
2. External TRIG control mode
When the laser is in the external TRIG control mode, the frequency and PWM (pulse width modulation) external control of the laser can be realized. At this time, the user needs to select the QS-EXT mode, and connect the TRIG line and GATE line to the corresponding interface of the upper computer with a shielded wire with BNC connector.
Source: Huyun Optoelectronics
