No, I’m afraid that isn’t enough information. Fluence is energy per unit area, and you won’t be able to determine the fluence without determining the profile of the beam spot.

So, what energy and what area? Well, for average fluence, you could use any area you like. If you shine the laser at a 3x3 m wall, the average fluence on the wall is 16 uJ per 9 square meters. But, of course, that isn’t very interesting. You know most of that area is seeing no fluence, and there’s a much smaller area that is experiencing a much higher fluence. That’s an exaggeration, but even if you use an area roughly the diameter of the beam, that’s still an average and there will be portions of the beam that are producing higher fluence on a smaller size scale. What area you use depends on what you want to know and also on the size scale of features of the beam profile.

Usually people are interested in size scales smaller than the beam. For example there are physical processes that require a threshold fluence to get started. Others are nonlinear and are very sensitive to the peak power. So, maybe you want to know the highest fluence seen on a very small size scale. The interesting size scale might be determined by the process you are investigating. Or, if your beam profile is very smooth, (like for example a Gaussian) then there is a size scale over which the beam intensity doesn’t change much, so the integral over that area approaches the local value.

For whatever area you choose, you need to determine the fraction of the laser energy that passes through that area. It can be a great help if you have a known calculable beam shape. For example, if you know your beam is Gaussian, you can relate a measurement of a large part of the beam to the beam profile and then determine the fluence over any part of the beam by computation. Suppose you have a beam profiling camera. In the image you can find the centered circle that contains 87% of the total energy. That is the 1/e^2 diameter. The average fluence is 87% of the measured energy over the aperture. However, knowing the shape, you know more than that. You now can infer the whole profile. For instance the peak fluence in the center of the Gaussian is 2 X the average fluence in the 1/e^2 circle. Etc.

Check my thesis. I calculated the laser fluence.

https://scholar.google.com/citations?view_op=view_citation&hl=en&user=ThDRac8AAAAJ&authuser=1&citation_for_view=ThDRac8AAAAJ:ULOm3_A8WrAC

Respected Mohammad Imran Bappy the link you provide me is not accessible. kindly provide me proper download accessible link.

I sincerely apologize. My paper might publish soon, so I will send you it then. But I can tell you a different approach, because you do not know the line space.

It is not possible to calculate it from the direct data.

Do laser texturing on a squared area (example 2 cm * 2 cm). The software will give you the laser texturing time. And you know the area of the textured region.

Fluence = P*t/A

But the power must be calculated which is being applied on the surface. You can't use the power written in the specification of your device, because there is a reduction.