Patent ID: 7327922
Filing Date: 2008-02-05
Classification: G02B

Abstract:
1. A method of producing a sealed microstructured optical fibre, the fibre comprising a first light guiding optical fibre portion comprising a cladding region with a plurality of spaced apart cladding voids extending longitudinally in the fibre axial direction and a core region bounded by said cladding region, the first light guiding fibre portion comprising an end with an end surface and a first outer cross-sectional dimension, the method comprising: forming or arranging a solid light transparent fibre portion at said end of the first light guiding fibre portion so as to provide a hermetic sealing of said cladding voids, said solid fibre portion comprising a second outer cross-sectional dimension and further comprising a first end facing the first light guiding fibre portion by being attached thereto or by sharing a common solid background material, and a second end opposite said first light guiding fibre portion; arranging said solid fibre portion so that when light is transmitted from the first light guiding fibre portion to the solid fibre portion, the light enters the solid fibre portion via the first end and leaves the solid fibre portion via the second end; said second outer cross-sectional dimension of said solid fibre portion being substantially equal to the first outer cross-sectional dimension of said first light guiding fibre portion; said first light guiding fibre portion comprising a Mode Field Diameter, MFD, defining a first optical field diameter of light at the first end of the solid fibre portion when light is transmitted from the first light guiding fibre portion to the solid fibre portion, and the transmitted light comprising a second optical field diameter when reaching the second end of the solid fibre portion; and said solid fibre portion being dimensioned so that the second optical field diameter is larger than the first optical field diameter.