#Intensity of laser light equation free#

Just divide the energy by the beam area.įor example, let’s calculate the fluence of a flat-top laser pulse of 10 mJ with a diameter of 4 mm. Let’s start with the simplest of cases: flat-top lasers, where the energy is distributed perfectly evenly all across the beam.Ĭalculating the fluence is a piece of cake. It would give you the exact intensity distribution in real time of your beam, including if there are any hotspots or defects. There are plenty of options out there, but the most efficient would be a profiling camera. The best way to know your profile is to use the proper tool. Do not mistake what I just said here, even though a typical stormtrooper manages to miss its target indefinitely, if you look directly at your beam, even if you can’t see it, really serious damages can occur in a matter of fractions of seconds. Great models can be developed to characterize a beam, but there’s nothing like actually looking at it to assess its profile. This factor refers to how closely a laser beam resembles a theoretical Gaussian distribution (or bell curve). So, to address that, there is what you call the M 2 factor. Why, you might ask? Mostly because a Gaussian power distribution maintains its shape way more efficiently over a distance than any other profile.Īll of that remains theories, and as you may already know, just as a laser beam spreads over distance, there can be a lot of divergence between theory and practice. They represent the majority of beam profiles you will come across. The three you will typically come across are FWHM, 1/e2, and D4σ, and they make sense only if the beam is Gaussian. This has led to many beam diameter definitions. They are very bright in the middle, and then slowly get dimmer at the edges.īecause laser light tapers off gradually, the boundary between “inside the beam” and “outside the beam” can be a bit fuzzy. Most lasers do not abruptly “turn off” at the edge of the beam. However, only flat-top lasers actually behave this way, and they represent a minority of lasers on the market. Measuring the diameter of such a laser is as straightforward as measuring the diameter of a circle on a piece of paper. There’s all the power in the world inside the red dot, and none at all outside of it. In popular culture, lasers are little red dots with a sharp outline. Bookmark the page and use it whenever it can save you time.

#Intensity of laser light equation free#

Gentec-EO's energy density and fluence calculator is publicly available and free to use. Hence, the division will have a slightly different scaling factor, depending on whether the laser has a flat-top profile, a gaussian profile, or something more irregular or exotic.

the beam’s profile) has a large influence on the peak fluence. How the energy is distributed within the laser beam (i.e.

How do you calculate fluence?Ĭalculating fluence is quite straightforward. This is helpful to avoid busting damage thresholds, and to ensure good process quality. Energy density actually refers to the same concept.Ī commonly used unit for laser fluence is Joules per square centimeter (J/cm 2). It tells you how concentrated a laser’s energy is. What is laser fluence? It is a measure of energy delivered per unit area.