Patent ID: 7956317
Filing Date: 2011-06-07
Classification: G01N,G02B

Abstract:
1. A bidirectional fibre optic spectroscopy probe comprising: a single fibre or bundle of fibres, each fibre having a proximal and a distal end and having a numerical aperture NA=n*sin θ, with θ being the acceptance angle that is the half angle of the acceptance cone of the fibre at its proximal end, an optical in/out coupler arranged adjacent or near said proximal end for coupling light into said proximal end of said fibre or bundle of fibres and for collecting light emerging from said proximal end, and an optical sensor element arranged adjacent or near said distal end and being adapted to sense a spectroscopic property of a sample to be brought in contact or in proximity to said sensor element characterized in that said in/out coupler has incoupling means that are adapted and arranged to couple light into said proximal end of said fibre or bundle of fibres with an incidence angle between θ and θ/x, wherein x is in the range from >1 to 10, and outcoupling means that are adapted to collect light emerging from said proximal end of said fibre with an angle smaller than θ/x, to thus enable the optical in/out coupler to couple higher order modes of light into said fibre or bundle of fibres and to collect back relatively lower order modes of light emerging from said proximal end of said fibre or bundle of fibres, wherein said fibre is adapted to operate as a converter of a propagating light modes from said relatively higher order modes of light into said relatively lower order modes of light.