Laser divergence is a measure of how much a laser beam spreads out as it travels over distance. It is typically measured in milliradians (mrad), which is a unit of angle. A milliradian is equal to 0.001 radians. A small divergence angle results in a more collimated beam which stays narrow over a greater distance, while a larger divergence angle results in a beam that spreads out more quickly over distance.
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