Pulse laser parameters

In recent years, with the continuous expansion of pulsed laser applications, the high output power and high single pulse energy of pulsed lasers is no longer a purely pursued goal. In contrast, the more important parameters are: pulse width, pulse shape and repetition frequency.
Among them, the pulse width is particularly important. Almost just by looking at this parameter, you can judge how powerful the laser is. The pulse shape (especially the rise time) directly affects whether the specific application can achieve the desired effect. The repetition frequency of the pulse usually determines the operating rate and efficiency of the system.

Single pulse energy
Single pulse energy: the laser energy carried by a single pulse.

Peak power & average power
1. Average power = single pulse energy * repetition frequency-the laser energy output per unit time in a repetition period.
2. Peak power = single pulse energy/pulse width-the highest power reached by a single pulse.

Pulse Width
1. Pulse width: the action time of a single pulse.
The sum of the time required for the number of photons to rise from the half maximum value to the peak value and the time required for the number of photons to fall from the peak value to the half maximum value. There are various magnitudes such as milliseconds (ms), microseconds (us), nanoseconds (ns), picoseconds (ps), femtoseconds (fs) and so on. The smaller the magnitude, the shorter the duration of laser action.
In the case of the same single pulse energy: the narrower the pulse width, the higher the peak power, and the longer the pulse width, the lower the peak power.
2. Rise time: the time required for the pulse signal to rise from 10% of the maximum value to 90%.
3. Fall time: the time required for the pulse signal to fall from 90% of the maximum value to 10%.

Repeat frequency
Repetition frequency: The number of laser pulses that are regularly output in a unit time (equivalent to the number of pulses recurring in one second).
In the case of the same average power: the lower the repetition frequency, the higher the single pulse energy, the higher the repetition frequency, the lower the single pulse energy.

Pulse control
1. External control: Load the frequency signal outside the power supply, and realize the control of the laser pulse by controlling the frequency and duty ratio of the load signal, so that the output pulse and the load pulse frequency are the same.
2. Internal control: The control principle is the same as that of external control, except that the frequency control signal is built into the drive power supply. There is no need to add additional signals to the power supply. You can choose a fixed built-in frequency or adjustable internal control frequency (host computer software or drive power display) .
3. Free frequency: refers to the frequency directly output by the laser, that is, the frequency output without frequency control. The frequency has a floating range and is not fixed.

Jitter value
Jitter value: The relative jitter of the rising edge of the light pulse of the pulsed laser relative to the rising edge of the trigger signal.