Critical particle size of contaminants in high and low modulus coatings for high-strength optical lightguides

The critical size of coating contamination for glass fiber lightguides requiring high prooftest levels was determined for high- and low-modulus coatings. The critical size for highly adhering coatings, regardless of the modulus, is between 3 and 10 μm. The critical size of coating contamination for coatings which exhibit poor coating to fiber adhesion was found to be on the order of the Griffith flaw size for the given prooftest level.