Coated optical fibers

Method for measuring the cavitation strength of a radiation cured coating comprising the steps of:

• making a sample by treating two plates by applying a liquid coating in between the two plates in a thickness of between 10 and 300 μm and over a certain area and by curing said coating with a UV-dose, the treatment of the two plates being such that the adhesion between the plates and the cured coating is sufficient to obtain cavitation before debonding sets in,
• placing the sample in a tensile testing apparatus, which is provided with a microscope, in such a way that a substantially parallel alignment and an acceptable compliance of the total tensile testing apparatus is obtained, running a deformation test on said sample while measuring the force at which a defined number of cavities starts to be visible through the microscope at a certain magnification, and calculating the stress by diving said force by the area of the coating applied and reporting said stress in relation to said cavities.