Nonlinear optical fibre method of its production and use thereof

A method of producing a microstructured optical fibre, the method comprising:

• (a) providing a preform by providing and arranging preform elements in a predetermined structure:
• at least one high-index rod to form a core region of the preform,
• and surrounding said high-index rod by first elements of capillary tubes and low-index rods to form an inner cladding region proximal to said at least one high-index rod, said capillary tubes and low-index rods providing first and second inner cladding features in a final fibre, and
• surrounding said at least one high-index rod, said first elements of capillary tubes and said low-index rods by outer elements of capillary tubes providing an outer part of the micro-structured cladding;
• and
• (b) consolidating said structure;
• and
• (c) drawing said preform to an optical fibre with pre-determined dimension under a controlled heat treatment.

An article comprising an optical fibre for transmitting light of at least one predetermined wavelength λ, the optical fibre having a longitudinal direction and a cross-section perpendicular thereto, the optical fibre comprising:

• (a) a core region comprising a core material of refractive index nc;
• and
• (b) a cladding region surrounding said core region and comprising low-index cladding features of refractive index n1 arranged in a background cladding material of refractive index nb,
• said cladding region further comprising first inner cladding features of refractive index n1 and second inner cladding features of refractive index n2, wherein n2 is lower than nc, and n2 is higher than n1,
• said first inner cladding features and said second inner cladding features being arranged proximal to said core region, and
• n2 being lower than nb.

A method of producing a microstructured optical fibre, the method comprising:

• providing a preform by providing and arranging preform elements in a predetermined structure:
• at least one high-index rod to form a core region of the preform,
• and surrounding said high-index rod by first elements of capillary tubes and low-index rods to form an inner cladding region proximal to said at least one high-index rod, said capillary tubes and low-index rods providing first and second inner cladding features in a final fibre, and
• surrounding said at least one high-index rod, said first elements of capillary tubes and said low-index rods by outer elements of capillary tubes providing an outer part of the micro-structured cladding;
• and
• drawing said preform to a preform cane with predetermined dimension under a controlled heat treatment, followed by drawing said preform cane to an optical fibre with predetermined dimension under a controlled heat treatment.

A method of producing a microstructured optical fibre, the method comprising:

• providing a preform by providing and arranging preform elements in a predetermined structure:
• at least one high-index rod to form a core region of the preform,
• and surrounding said high-index rod by first elements of capillary tubes and low-index rods to form an inner cladding region proximal to said at least one high-index rod, said capillary tubes and low-index rods providing first and second inner cladding features in a final fibre, and
• surrounding said at least one high-index rod, said first elements of capillary tubes and said low-index rods by outer elements of capillary tubes providing an outer part of the micro-structured cladding;
• and
• drawing said preform to an optical fibre with predetermined dimension under a controlled heat treatment.