Disclosed is an example method to reduce waveguide scattering loss.

An improved lens structure (40) is provided which reduces the scattering and/or reflection losses in an optical cavity.

These structures significantly improve the light collection efficiency and reduce the scattering and crosstalk losses in the dielectric layer.

The method minimizes the need for path-length measurement or extinction coefficient determination or estimation of scattering losses.

Until now, it was considered that the nanoparticles should be as small as possible in order to limit losses by light scattering.

The present invention relates to the use of flexible hoses capable of handling high pressure fluids and providing a barrier against permeation loss in air conditioning and refrigeration systems.

A planar waveguide that has a graded index layer at the core/cladding interface to reduce scattering losses due to core/classing interfave roughness.