Multimode Laser Beam Profile

The figure below shows the intensity profile of a monochromatic beam from a numerical simulation where the power is well spread over all guided modes.

Multimode laser beam profile.

A comparison of gaussian and multimode beams with equal energy was carried out in order to estimate influence of beam profile only. 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. 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. Initial profile input angle 0.

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. 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. 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. Here we investigated the effect of changing the input angle of a focused laser beam into a multimode fiber patch cable.

B 3d beam intensity profiles of the multimode dpss laser at the constructed far field using a converging lens.