Method of fabricating an optical fibre preform
A method of fabricating an optical fibre preform is disclosed comprising using a subtractive process on an optical monolith to define therein at least a transverse section of the optical fibre preform, wherein the transverse section comprises at least two regions with different refractive indexes. An optical fibre preform fabricated in accordance with the method is also disclosed along with a method of assembling optical components using a subtractive process to define a first interconnecting feature in or for use with a first optical component; using a subtractive process to define a second interconnecting feature in or for use with a second optical component; and coupling the first and second components together using the first and second interconnecting features such that the coupling dictates a passive alignment of the first and second components.
1 . A method of fabricating an optical fibre preform comprising:
using a subtractive process on an optical monolith to define therein at least two transverse sections of the optical fibre preform;
stacking and coupling the at least two transverse sections to form a stacked optical fibre preform;
wherein the at least two transverse sections comprise at least two regions with different refractive indexes;
wherein the coupling dictates a passive alignment of the at least two transverse sections;
wherein the optical fibre preform is formed from two or more transverse sections having different hollow core structures configured to form at least one continuous longitudinally varying hollow core structure; and
wherein the subtractive process comprises laser assisted etching comprising laser writing a structure in the optical monolith and chemically etching the structure to obtain the at least two transverse sections.
2 . The method according to claim 1 wherein at least one of the transverse sections comprises a structured core.
3 . The method according to claim 1 wherein the coupling is achieved using at least one interconnecting feature defined in at least one of the at least two transverse sections.
4 . The method according to claim 3 wherein the at least one interconnecting feature in the at least one transverse section is configured for direct or indirect coupling to another transverse section.
5 . The method according to claim 3 wherein the at least one interconnecting feature is configured for coupling using one or more of: a pin, a dowel, a sphere, a dove tail joint, a threaded portion, a ring, a plug and socket arrangement, or a self-centering locator.
6 . The method according to claim 1 further comprising bonding the at least two transverse sections in the stacked optical fibre preform.
7 . The method according to claim 6 wherein the bonding comprises one or more of: catalysis bonding; ultrafast laser bonding; optical contact bonding; or laser welding.