Super-luminescent diode

Claim 1

In a super luminescent gain guided light emitting device which includes: a semiconductor body having spaced first and second opposed end faces with an active region extending therebetween, said end faces being spaced apart a given distance at said active region, said device having a first current confining structure comprising a linear strip of material adjacent to a side of said active region, said structure being arranged to form an effective optical beam path between the end faces at said active region, said beam path having an optical axis of symmetry determined by and parallel to said current confining structure, said path being oriented so that said axis of symmetry intersects said end faces, said path having a given width transverse said optical axis, wherein the improvement comprises: the optical axis of symmetry is inclined at an angle and non-parallel relative to a direction perpendicular to at lest one of said end faces, the tangent of said angle being greater than or equal to the width of said effective optical beam path divided by said given distance; said angle has a value such that light parallel to said axis incident on said at least one end face and reflected from that one end face toward said beam path is caused to be substantially refracted out of the beam path when incident on the boundary between the effective optical beam path and the adjacent semiconductor body outside the beam path; the values of said tangent and angle being such that together said values tend to minimize the spectral modulation within said path.