Method for the generation of light of a given polarization state

A light polarization apparatus having a light input for light and an output for light of predetermined polarization and comprising:

• a hollow tubular member having the light input, an optical axis and a light-reflecting inner surface parallel to the optical axis and a light-reflecting further surface along a part of a cross-sectional plane of an inner space of the tubular member that is remote from the light input and is normal to the optical axis and in said inner space;
• an open end for inputting said light;
• an output end for light passed through and along said hollow tubular member;
• a polarization-selective splitter arrangement having an input operationally connected to the output of said tubular member and a first output for light of said predetermined polarization, a second output for light of a polarization different from said predetermined polarization, said second output for said light of different polarization being coupled to said output of said tubular member so as to apply said light of different polarization from said second output back into said tubular member and onto said light-reflecting inner and further surfaces.