Photonic crystal fibres
AssigneeCrystal Fibre A/S
InventorsPhilip St. John Russell, Timothy Adam Birks, Jonathan Cave Knight
Life of this patent
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Abstract
In a method of producing a photonic crystal fibre, a preform (300) that includes holes is formed and the preform (300) is drawn into a fibre. The method includes the step of applying a pressure differential to certain of the holes to control changes in the fibre structure during the draw.
Claims10
A method of making a photonic crystal fibre, comprising:
- (i) providing a plurality of elongate canes, each having a longitudinal axis, a first end and a second end, at least some of the canes being capillaries each having a hole parallel to the longitudinal axis of the cane and running from the first end of the cane to the second end of the cane;
- (ii) forming a preform by forming the canes into a stack and fusing them together, the canes being arranged with their longitudinal axes substantially parallel to each other and to the longitudinal axis of the stack;
- (iii) drawing the preform into the fibre whilst maintaining the hole of at least one capillary in communication with a source of fluid at a first pressure whilst maintaining the pressure around the said hole at a second pressure, wherein the hole at the first pressure becomes, during the drawing process, a size different from that which it would have become without the pressure difference.
In a method of making a photonic crystal fibre, comprising forming a preform by fusing a plurality of elongate canes, at least some of the canes being capillaries and drawing said preform to form the fiber, the improvement comprising pressurization or evacuation of at least one of the holes provided by the capillaries during the drawing whilst maintaining said hole in communication with a source of fluid at a first pressure different from atmospheric pressure, so that the hole at the first pressure becomes, during the drawing process, a size different from that which it would have become without the pressure difference.
Dependencies are inferred from the claim text.