GB2271433A

GB2271433A - Optical fibre fusion splicing with reciprocal movement

Info

Publication number: GB2271433A
Application number: GB9221149A
Authority: GB
Inventors: David Lister Myers
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-10-08
Filing date: 1992-10-08
Publication date: 1994-04-13
Also published as: GB9221149D0

Abstract

The tensile strength of an optical fibre fusion splice is increased and the attenuation of a splice reduced by reciprocation of one of the optical fibres to be spliced relative to the other during fusing, but after the fibres have been merged. <IMAGE>

Description

AN OPTICAL FIBRE FUSION SPLICING TECHNIQUE This invention relates to the improved quality of splice achieved using an optical fibre fusion splicer by reciprocation of one of the optical fibres to be spliced relative to the other during fusing.

The process of fusion splicing optical fibre is well established.

After aligning the two optical fibres to be joined, a controlled high voltage electric arc is struck across the ends of the optical fibres such that they become partially molten. The optical fibres are brought together under automatic control so that they merge.

The present invention provides a technique for increasing the tensile strength and reducing the optical loss of a splice, comprising a device or devices for aligning the two optical fibres to be joined, a device or devices for controlled heating of the optical fibres, such as a high voltage electric arc, a mechanism or mechanisms to allow at least one optical fibre to be moved in both directions along its axis and a system to control the movement of this (or these) mechanism(s) fully automatically or both automatically and manually. The optical fibres are prepared and aligned in the manner usual for fusion splicing.

The optical fibres are heated using the controlled heating device and are brought together under automatic control such that they merge by a controlled amount, using the mechanism(s) described above, in the manner usual for fusion splicing. The optical fibres are continually heated as one of the optical fibres reciprocates relative to the other at a controlled amplitude and frequency for a controlled period.

A specific embodiment of the invention will now be described by way of an example with reference to the accompanying drawing in which: Figure 1 shows an arrangement of a specific fusion splicer.

Figure 2 shows a graph of the power of the electric arc and the relative axial displacement of the optical fibre ends against time.

Referring to the drawing, the splicing machine comprises an alignment block 4 into which grooves have been machined to align the optical fibres 8 and into which electrodes 5 are mounted to provide a high voltage electric arc, two translation stages 3 each driven in an axial direction by a thumbwheel 2 and each being attached to a clamping mechanism 6 which firmly grips an optical fibre, a piezo-electric transducer 9 which also drives one of the clamping mechanisms 6 in an axial direction, an electronic control circuit 10 which generates voltages to move the piezo-electric transducer 9 and to strike an electric arc across the electrodes 5, and a user interface comprising a display 11, a keypad 12 and a microscope 1 to view the optical fibres 8.

Two prepared optical fibres 8 are placed in the translation clamps 6 such that they rest with their axes along the groove in the alignment block 4. The ends of the optical fibres are moved by turning the thumbwheels 2 until they can be seen through the microscope 1 to be just touching. The automatic electronic control sequence is initiated by pressing a key on the keypad 12.

In the manner usual for fusion splicing, the ends of the optical fibres 8 are automatically moved apart by the control electronics reducing the voltage applied to the piezoelectric transducer 9 to a relative axial displacement 15, and then an electric arc of current 13 is struck across the electrodes 5 for a time 18. The ends of the optical fibres are then brought together by the control electronics increasing the voltage applied to the piezoelectric transducer to a relative axial displacement of zero, and as they touch the current of the electric arc is increased to 14 and the ends of the optical fibres are further brought together so that they merge by a relative axial displacement 16. This position is maintained for a time 19.

The quality of the splice is then improved by a series of reciprocations 17 where the relative axial displacement of the optical fibres is varied by the control electronics decreasing and increasing the voltage applied to the piezoelectric transducer by controlled amounts at a controlled frequency whilst the current of the electric arc is maintained at 14 for a time 20. The reciprocations are then stopped and the current of the electric arc is maintained at 14 for a further time 21.

Claims

1. The optical power loss of an optical fibre fusion splice is reduced by reciprocation of one of the optical fibres with respect to the other as the optical fibres are continually heated after they have been merged.

2. The tensile strength of an optical fibre fusion splice is increased by reciprocation of one of the optical fibres with respect to the other as the optical fibres are continually heated after they have been merged.

3. The optical power loss caused by the axial misalignment of the two optical fibres in a fusion splice is reduced by reciprocation of one of the optical fibres with respect to the other as the optical fibres are continually heated after they have been merged.

4. The axial misalignment of the two optical fibres in a fusion splice is reduced by reciprocation of one of the optical fibres with respect to the other as the optical fibres are continually heated after they have been merged.

5. A method of improving splice quality substantially as described herein with reference to figures 1-2 of the accompanying drawing.