Methods for stripping an optical fiber coating using blue or blue-violet radiation

A method of processing an optical fiber having a central glass portion defined by a core and a cladding and a coating surrounding the central glass portion that is transparent to a processing wavelength and that has an optical-damage threshold intensity at the processing wavelength, comprising:

• a) irradiating a portion of the coating with at least one first radiation beam having the processing wavelength, wherein the processing wavelength is either 405 nm or 445 nm, and having an intensity greater than the optical-damage threshold intensity to create a damaged coating portion;
• and
• b) irradiating the damaged coating portion with at least one second radiation beam having the processing wavelength of either 405 nm or 445 nm and an intensity that is less than the optical-damage threshold intensity;
• wherein the method further includes forming the at least one second radiation beam from the at least one first radiation beam by defocusing the at least one first radiation beam.

A method of processing an optical fiber, comprising:

• a) movably holding the optical fiber, wherein the optical fiber has a central glass portion defined by a core and a cladding and a coating surrounding the central glass portion and having a diameter, the coating being substantially transparent to a processing wavelength and having an optical-damage threshold intensity at the processing wavelength;
• b) forming at least one first focused radiation beam having the processing wavelength, a depth of focus, and a spot size that is less than the diameter of the coating within the depth of focus, and an intensity greater than the optical-damage threshold within at least a portion of the depth of focus;
• c) arranging the optical fiber within the depth of focus and irradiating a portion of the coating with the at least one focused radiation beam to create a damaged coating portion;
• d) defocusing the at least one focused radiation beam to define at least one defocused radiation beam having an intensity that is less than the optical-damage threshold intensity;
• and
• e) irradiating the damaged coating portion with the at least one defocused radiation beam that irradiates the entire diameter of the coating.