# Calculating Nd:YAG Laser pulse energy

• bakelas83
In summary, the pulse energy in a pulsed Nd:YAG laser can be calculated by multiplying the mean power by the pulse period or dividing the mean power by the repetition rate. The pulse power is affected by the pulse duration, but the pulse energy remains constant. The laser power cannot be calculated just from knowing the electrical current, as different lasers have different efficiencies. Either the laser power must be measured at the current setting or a graph can be made from measurements at different currents to determine the laser power at any given current.
bakelas83
I have a question, I used pulsed Nd:YAG laser to weld a steel part but I didn’t measure the pulse energy during the experiment. I was wondering if there is a way to calculate it somehow?
I have laser pulse duration, frequency (repetition rate), and laser (mean) power.
Thanks

Welcome to Physics Forums

The pulse energy is (mean) power x pulse period, or equivalently
(mean power) / (rep. rate)​

This makes sense if you think about the units, and the fact that power is energy-per-second:
$$\frac{( \text{energy/second)}}{ \text{(pulses/second)}} = \text{(energy/pulse)}$$

Yes. You are right. But doesn’t the pulse duration have an effect on the pulse power?
I mean does the pulse power change directly with change in pulse duration or not?
Thanks

Yes, it affects the pulse power. But it does not affect the pulse energy, which was your original question.

Pulse power = (pulse energy) / (pulse duration)​

Thanks. I have one other question. The laser machine I was working with had an adjustment option for I (electric current in terms of mA) instead of laser power. How can I find laser power with this information?

There is no way to calculate laser power just from knowing the current. Different lasers have different efficiencies for converting the electrical energy into laser beam energy.

You would have to measure the laser power at the current setting you used. Or, measure the laser power at several different currents and make a graph (should be a straight line, if this YAG laser emits in the infrared), from which you can get the laser power at any current.

## 1. What is a Nd:YAG laser?

A Nd:YAG laser is a solid-state laser that uses a neodymium-doped yttrium aluminum garnet crystal as the active medium. It produces a near-infrared light beam with a wavelength of 1064 nanometers.

## 2. How is the pulse energy of a Nd:YAG laser calculated?

The pulse energy of a Nd:YAG laser is calculated by dividing the total energy output of the laser by the number of pulses produced in a given time period. This can be measured using a laser energy meter.

## 3. What determines the pulse energy of a Nd:YAG laser?

The pulse energy of a Nd:YAG laser is determined by the power of the laser, the duration of each pulse, and the frequency of the pulses. These parameters can be adjusted to control the pulse energy output of the laser.

## 4. How does the pulse energy affect the performance of a Nd:YAG laser?

The pulse energy of a Nd:YAG laser is directly related to its cutting or drilling capability. Higher pulse energies can produce deeper cuts or holes, while lower pulse energies are better suited for surface treatment or welding.

## 5. Are there any safety considerations when working with Nd:YAG laser pulse energy?

Yes, Nd:YAG lasers can be hazardous to the eyes and skin. It is important to wear appropriate protective gear, such as laser safety glasses, and follow proper safety protocols when working with these lasers to avoid injury.

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