In the case of the multi-plane construction lasers, we can see a slight difference in the power of the projected beams (vertically and horizontally). This phenomenon can also be seen when we rotate the laser around its axis (the beam may change slightly – it may be better or less visible).
This is a natural effect and it results from the construction of the equipment laser system. The light beam, generated by the laser diode must pass through the optical system in which it is focused. Then it goes to the prism, where it is refracted at an angle of 90°. The cross-section of the laser beam is oval while the cross-section of the prism is circular. So, at the point of contact with the prism, the light is not evenly distributed, which results in a slight difference in the power of the displayed beams.
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