An optical coupler, the optical coupler being usable with a first optical fibre and a second optical fibre. The second optical fibre defines a second fibre coupling section and a second fibre transmitting section extending from the second fibre coupling section. The second fibre coupling section defines a radially outwardmost peripheral surface, the radially outwardmost peripheral surface defining a peripheral surface coupling portion. The optical coupler includes a coupler first end section and a substantially opposed coupler second end section, the coupler first end section defining a first coupling surface. The optical coupler defines a second coupling surface extending along the coupler first and second end sections. The first coupling surface is optically couplable with the first optical fibre and the second coupling surface is positionable so as to extend substantially parallel to the peripheral surface coupling portion and to be optically coupled with the peripheral surface coupling portion. The optical coupler has optical and geometrical properties such that substantially all the light guided to the first coupling surface by the first optical fibre is directed towards the second coupling surface and into the second optical fibre through the peripheral surface coupling portion so as to be guided into the second fibre coupling section for transmission into the second fibre transmitting portion.