Optical fibre connectors

An optical fibre connector for removably connecting two optical fibres in axial alignment comprising, in respect of each said optical fibre, a precision made cylinder having a precision through hole on its longitudinal axis for the reception of an end portion of said optical fibre, a recess formed in one end of said precision made cylinder, said recess having a circular cross-section, the axis of said precision through hole being aligned with the axis of said recess, an accurate precision made transparent sphere lens, said sphere lens being bonded in said recess, the end of said optical fibre being connected to said sphere lens by bonding without gaps therebetween such that the axis of said optical fibre is in alignment with the center of said sphere lens, the material of said sphere lens being selected from a group of relatively hard materials with a refractive index of approximately 2.0 comprising calcium molybdate, yttrium gallium garnet, gadolinium gallium garnet and synthetic sapphire, said lens having its outer surface coated with a thin film of anti-reflection material, and connecting means, said connecting means being adapted to connect together said two precision made cylinders with the axes of said optical fibres parallel and substantially in alignment.