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.

Multimode laser beam profile.

Intensity profile of a multimode beam which has about the maximum possible m 2 value for efficient launching into the fiber. 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. 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. Here we investigated the effect of changing the input angle of a focused laser beam into a multimode fiber patch cable.

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. B 3d beam intensity profiles of the multimode dpss laser at the constructed far field using a converging lens. Initial profile input angle 0. 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.

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.