Attenuation across optical fiber splice

Claim 3

A method according to claim 1 wherein D 3 equals D 2 .

Claim 4

A method according to claim 1 wherein P 1 is measured before the splice is completed.

Claim 5

A method according to claim 2 wherein P 1 is measured before the splice is completed.

Claim 6

A method according to claim 1 wherein P 1 is measured after the splice is completed.

Claim 7

A method according to claim 2 wherein P 1 is measured after the splice is completed.

Claim 8

A method according to claim 1 wherein D 1 is 0 to about 50 microns and D 2 is about 50 microns to about 500 microns.

Claim 9

A method according to claim 2 wherein D 1 is 0 to about 50 microns and D 2 is about 50 microns to about 500 microns.

Claim 10

A method according to claim 1 wherein D 1 is 0 to about 20 microns and D 2 is about 100 microns to about 300 microns.

Claim 11

A method according to claim 2 wherein D 1 is 0 to about 20 microns and D 2 is about 100 microns to about 300 microns.

Claim 12

A method according to claim 1 wherein the fiber ends are positioned in substantial axial alignment by moving at least one of the fiber ends to maximize the optical signal in the receiving end.

Claim 13

A method according to claim 2 wherein the fiber ends are positioned in substantial axial alignment by moving at least one of the fiber ends to maximize the optical signal in the receiving end.

Claim 14

A method according to claim 1, the distance D 2 being sufficiently large that variations in P 2 are small for moderate lateral misalignments between ends of the first and second fibers, the lateral misalignment being as large as 20 micrometers.

Claim 15

Apparatus for measuring an optical signal across an optical fiber splice between a first optical fiber and a second optical fiber and calculating the attenuation of the splice, comprising: means for holding and precisely positioning an end of the first fiber relative to an end of the second fiber for splicing; means for launching an optical signal into the first fiber; means for measuring the optical signal in the second fiber; means for aligning substantially axially the fiber ends; means for positioning the fiber ends at a distance D 2 and measuring optical signal P 2 in the second fiber; means for positioning the fiber ends at a distance D 1 and measuring optical signal P 1 in the second fiber; and means for calculating the attenuation across the optical fiber splice using the formula dB=10 log (P.sub.1 /RP.sub.2) where R is a predetermined constant determined from P and P R , P being an optical power of a second optical signal measured in a sample fiber of a type similar to the first fiber, and P R is an optical power of the second optical signal measured in the sample fiber when two parts thereof are substantially axially aligned and are positioned at a distance D 3 , P and P R being created by launching the second signal into the sample fiber, D 2 and D 3 being greater than D 1 .

Claim 16

Apparatus for measuring an optical signal across an optical fiber splice between a first optical fiber and a second optical fiber and calculating the attenuation of the splice, comprising: means for holding and precisely positioning an end of the first fiber relative to an end of the second fiber for splicing; means for launching an optical signal into the first fiber; means for measuring the optical signal in the second fiber; means for aligning substantially axially the fiber ends; means for positioning the fiber ends at a distance D 2 and measuring optical signal P 2 in the second fiber; means for positioning the fiber ends at a distance D 1 and measuring optical signal P 1 in the second fiber; and means for calculating the attenuation across the optical fiber splice using the formula dB=10 log (P.sub.1 /RP.sub.2) where R is a predetermined constant determined from P and P R , P being an optical power of a second optical signal measured in a sample fiber of a type similar to the first fiber, and P R is an optical power of the second optical signal measured in the sample fiber when two parts thereof are substantially axially aligned and are positioned at a distance D 3 , P and P R being created by launching the second signal into the sample fiber, D 2 and D 3 being greater than D 1 .

Claim 17

Apparatus of claim 14 wherein the means for launching an optical signal into the first fiber is an optical coupler capable of side launching the optical signal into the fiber through the cladding of the fiber.

Claim 18

Apparatus of claim 15 wherein the means for measuring the optical signal in the second fiber is an optical coupler capable of withdrawing the optical signal through the cladding of the fiber.