A COUPLING ARRANGEMENT BETWEEN A MULTI-MODE LIGHT SOURCE AND AN OPTICAL FIBER THROUGH AN INTERMEDIATE OPTICAL FIBER LENGTH

摘要

A coupling arrangement for non-axial transfer of light power between a multi - mode light source (LS), having a substantially circu lar emission with a divergence angle .alpha.s, and a multi-mode optical fiber (FF) with a cross section Ac, through a length of an intermediate feeding multi-mode optical fiber (IF) having an end with cross section area Af coupled with said light source (LS) and one portion fused to said optical fiber (FF). Said feeding fiber (IF) has a progressively tapered portion and is fused to said multi-mo de optical fiber (FF) at a region of the tapered fiber, and in that the relationship between the acceptance angle .alpha.f of the feeding fiber (IF) and the emission angle .alpha.s of the light source (LS) is expressed by: .alpha.f = k . .alpha.s where k is a positive constant greater than 1.