Method for monitoring the concentricity of plastic coatings on optical fibers

Claim 1

A method for monitoring the concentricity of a coating on an optical fiber, said coating being substantially transparent, comprising the steps of: illuminating said coated fiber with a beam of light from a narrowband source; observing the backscattered light pattern generated by said beam of light; and determining the concentricity or eccentricity of said coating on said optical fiber from the absence or presence, respectively, of at least one predetermined intensity peak located between the central outermost and the central innermost peaks in the backscattered light pattern, said predetermined intensity peak resulting from the rays of minimum deviation in said beam of light which traverses the optical fiber only once.

Claim 2

A method for monitoring the concentricity of a coating on an optical fiber, said coating being substantially transparent, comprising the steps of: illuminating said coated fiber with a beam of light from a narrowband source; observing the backscattered light pattern generated by said beam of light; and determining the concentricity or eccentricity of said coating on said optical fiber from the absence or presence, respectively, of at least one predetermined intensity peak located between the central outermost and the central innermost peaks in the backscattered light pattern, said predetermined intensity peak resulting from the rays of minimum deviation in said beam of light which traverses the optical fiber only once.

Claim 4

A method for controlling an applicator which applies a coating onto an optical fiber, said coating being substantially transparent, comprising the steps of: illuminating the fiber onto which the coating has been applied with a beam of light from a narrowband source perpendicular to the axis of said fiber; observing the backscattered light pattern generated by said beam of light; determining the concentricity or eccentricity of said coating on said optical fiber from the absence or presence, respectively, of at least one predetermined intensity peak located between the central outermost and central innermost peaks in the backscattered light pattern, said predetermined intensity peak resulting from the rays of minimum deviation which traverse the optical fiber only once; and adjusting the position of said applicator until the absence of said predetermined intensity peak is observed in the backscattered light pattern.

Claim 5

A method for controlling an applicator which applies a coating onto an optical fiber, said coating being substantially transparent, comprising the steps of: illuminating the fiber onto which the coating has been applied with a beam of light from a narrowband source perpendicular to the axis of said fiber; observing the backscattered light pattern generated by said beam of light; determining the concentricity or eccentricity of said coating on said optical fiber from the absence or presence, respectively, of at least one predetermined intensity peak located between the central outermost and central innermost peaks in the backscattered light pattern, said predetermined intensity peak resulting from the rays of minimum deviation which traverse the optical fiber only once; and adjusting the position of said applicator until the absence of said predetermined intensity peak is observed in the backscattered light pattern.

Claim 7

A method for controlling an applicator which applies a coating onto an optical fiber, said coating being substantially transparent, comprising the steps of: illuminating the fiber onto which the coating has been applied with a beam of light from a narrowband source perpendicular to the axis of said fiber; converting the backscattered light pattern generated in response to said beam of light into an electrical signal whose intensity variations, as a function of time, correspond to the spatial light intensity variations in said backscattered light pattern; determining the absence or presence of a predetermined intensity maxima in said electrical signal, said predetermined intensity maxima located between the central outermost and central innermost maximas in said electrical signal, said predetermined intensity maxima resulting from an intensity peak in said backscattered light pattern which results from the rays of minimum deviation which traverse the optical fiber only once; and adjusting the position of said applicator until said predetermined intensity maxima in said electrical signal is not present.

Claim 8

A method for controlling an applicator which applies a coating onto an optical fiber, said coating being substantially transparent, comprising the steps of: illuminating the fiber onto which the coating has been applied with a beam of light from a narrowband source perpendicular to the axis of said fiber; converting the backscattered light pattern generated in response to said beam of light into an electrical signal whose intensity variations, as a function of time, correspond to the spatial light intensity variations in said backscattered light pattern; determining the absence or presence of a predetermined intensity maxima in said electrical signal, said predetermined intensity maxima located between the central outermost and central innermost maximas in said electrical signal, said predetermined intensity maxima resulting from an intensity peak in said backscattered light pattern which results from the rays of minimum deviation which traverse the optical fiber only once; and adjusting the position of said applicator until said predetermined intensity maxima in said electrical signal is not present.

Claim 10

A method for controlling an applicator which applies a coating onto an optical fiber, said coating being substantially transparent, comprising the steps of: illuminating the fiber onto which the coating has been applied with a beam of light incident to a cross-sectional axis of said fiber at a first angle; illuminating the coated fiber with a beam of light incident at a second angle; converting the first backscattered light pattern generated in response to said beam of light incident to said fiber at said first angle into a first electrical signal whose intensity variations, as a function of time, correspond to the spatial light intensity variations in said first backscattered light pattern; converting the second backscattered light pattern generated in response to said beam of light incident to said fiber at said second angle into a second electrical signal whose intensity variations, as a function of time, correspond to the spatial light intensity variations in said second backscattered light pattern; determining the absence or presence of a first predetermined intensity maxima in said first electrical signal, said first predetermined intensity maxima located between the central outermost and central innermost maximas in said first electrical signal, said first predetermined intensity maxima resulting from an intensity peak in said first backscattered light pattern which results from the rays of minimum deviation which traverse the optical fiber only once in said beam incident at said first angle; determining the absence or presence of a second predetermined intensity maxima in said second electrical signal, said second predetermined intensity maxima located between the central outermost and central innermost maximas in said second electrical signal, said second predetermined intensity maxima resulting from an intensity peak in said second backscattered light pattern which results from the rays of minimum deviation which traverse the optical fiber only once in said beam incident at said second angle; and adjusting the position of said applicator until said first predetermined intensity maxima in said first electrical signal is not present and said second predetermined intensity peak in said second electrical signal is not present.

Claim 11

A method for controlling an applicator which applies a coating onto an optical fiber, said coating being substantially transparent, comprising the steps of: illuminating the fiber onto which the coating has been applied with a beam of light incident to a cross-sectional axis of said fiber at a first angle; illuminating the coated fiber with a beam of light incident at a second angle; converting the first backscattered light pattern generated in response to said beam of light incident to said fiber at said first angle into a first electrical signal whose intensity variations, as a function of time, correspond to the spatial light intensity variations in said first backscattered light pattern; converting the second backscattered light pattern generated in response to said beam of light incident to said fiber at said second angle into a second electrical signal whose intensity variations, as a function of time, correspond to the spatial light intensity variations in said second backscattered light pattern; determining the absence or presence of a first predetermined intensity maxima in said first electrical signal, said first predetermined intensity maxima located between the central outermost and central innermost maximas in said first electrical signal, said first predetermined intensity maxima resulting from an intensity peak in said first backscattered light pattern which results from the rays of minimum deviation which traverse the optical fiber only once in said beam incident at said first angle; determining the absence or presence of a second predetermined intensity maxima in said second electrical signal, said second predetermined intensity maxima located between the central outermost and central innermost maximas in said second electrical signal, said second predetermined intensity maxima resulting from an intensity peak in said second backscattered light pattern which results from the rays of minimum deviation which traverse the optical fiber only once in said beam incident at said second angle; and adjusting the position of said applicator until said first predetermined intensity maxima in said first electrical signal is not present and said second predetermined intensity peak in said second electrical signal is not present.