There could be several reasons why a laser machine fiber-optic cable broke:

1.Mechanical stress: Laser machine fiber-optic cable are often subjected to mechanical stress due to factors such as bending, twisting, or tension. Over time, this stress can weaken the fiber and eventually lead to a break.

2.Excessive power levels: If the laser machine is operated at power levels beyond the recommended specifications for the fiber, it can cause excessive heating and damage the fiber, leading to a break.

3.Contamination: Foreign particles or contaminants on the fiber's surface can interfere with the transmission of laser light, causing localized heating and eventual breakage.

4.Aging and wear: Like any material, fibers can degrade over time due to aging or wear and tear. This degradation can weaken the fiber's structure and make it more prone to breaking.

5.Improper handling: Rough handling or mishandling of the fiber, such as excessive bending, sharp bends, or tugging, can put stress on the fiber and cause it to break.

6.Manufacturing defects: In some cases, the fiber may have had undetected defects introduced during the manufacturing process, which can lead to premature failure.

It is important to note that proper maintenance, regular inspections, and adherence to manufacturer's guidelines can help minimize the risk of fiber breakage and ensure the longevity of laser components.