Single mode lasing gaussian beam results in better reproducibility of analytical signals compared to multimode lasing while laser energy reproducibility was the same for both cases.
Multimode laser beam profile.
Here we investigated the effect of changing the input angle of a focused laser beam into a multimode fiber patch cable.
As the input angle was increased the proportion of meridional rays to skew rays increased first forming a top hat and then a donut beam profile.
For example light from stationary high power lasers of various types can be sent to material processing stations for cutting or welding where e g.
Initial profile input angle 0.
The maximum beam spot size is 3 4 mm at z 0 and at 50 cm away from the laser it becomes 5 8 mm.
Intensity profile of a multimode beam which has about the maximum possible m 2 value for efficient launching into the fiber.
Modifying beam profiles with multimode fibers by increasing the launch angle of a gaussian beam into a multimode fiber the output beam profile can be modified.
Focusing the light normal to the fiber face produced a near gaussian output beam profile figure 1 and increasing the angle resulted in top hat figure 2 and donut shaped figure 3 beam profiles.
Multimode fibers are used for the transport of light from a laser source to the place where it is needed particularly when the light source has a poor beam quality and or the high optical power requires a large area of the fiber core.