GB1225115A - - Google Patents

Abstract

1,225,115. Fibre optics. JOSEPH LUCAS (INDUSTRIES) Ltd. June 21, 1968 [July 24, 1967], No.33931/67. Heading G2J. Optical apparatus used to transmit light from two or more cables to a further optical cable comprises a block of transparent material 11 which has a first surface containing bores 13 to receive two or more optical cables and a second surface 16 to receive one optical cable; the boundary surface of the block and the medium surrounding providing total internal reflection of the light travelling in the block. The block 11 is made of transparent synthetic resin material and is formed with diametrically opposite parallel flat surfaces 12. The bores 13 are inclined towards one another and overlap to terminate into a single bore 14 having a flat surface 15. The narrow end of the block 11 is formed into a cylindrical portion 17 coaxial with the bore 14 and has a flat surface 16 parallel with surface 15. The surface of the block 11 between the surfaces 15 and 16 is highly polished and may be coated with a layer (not shown) of refractive index that will provide total internal reflection. Alternatively the block may be supported in a hermetically sealed enclosure so that air can be used as the surrounding media. In use a length of the cables (10a) (10b) Fig. 2, (not shown) are stripped to uncover the fibres which are coated with a transparent adhesive and urged along bores 13 until the ends of the fibres adhere to the surface 15. A length of a third cable (10c) Fig. 2, is stripped and inserted into a metal ferrule 18 which is crimped at one end to grip the cable. The portion 17 is then inserted into the other end of the ferrule until the fibre ends abut against surface 16 and a clear adhesive is used to secure the fibres to the surface. Alternatively the cables may be secured to the block by synthetic resin welding techniques. In a modification the surface is provided with a reflective material such as aluminium.