Single or multiple laser beam homogenising apparatus for e.g. optical pumping of optical fibre

摘要

The homogenising piece (1) has a receiver section (FR) at one end for the laser light emitted by a source (SI), an emitting section (FE) at the other and an external surface between the sections which forms a refractive surface with the surrounding medium ensuring total multiple reflections of the diverging rays received by the receiver. The piece has a cylindrical of prismatic shape with a polygonal cross-section and may have an increasing or decreasing cross-section between the ends; its refractive index preferably lies between 1.42 and 1.6. The laser beam is diverged by a distinct convergent or divergent Fresnel lens or diffractive optics (LD) which may be integrated into the receiving surface.