A new technique for producing radial gradient refractive index (r-GRIN) titanium-doped silica lenses
has been developed employing a sol-gel leaching method. The obtained lenses possess a parabolic index
distribution and give good images with high resolution. They also show high coupling efficiency with
optical fibers and enable a low-loss large distance space transmission of light between optical fibers.
Furthermore the sol-gel r-GRIN lenses show a high degree of environmental stability as expected for the