Nano-imprinting of polymer planar waveguide Bragg Gratings

A nano-imprinting technique for fabricating polymer planar waveguide Bragg gratings is presented. The Bragg grating pattern was formed on a photoresist layer by the interference of two laser beams directed at specific angles on this layer. A mould of this grating pattern was taken on Poly Di-methyl-siloxane (PDMS) polymer. A UV15 polymer cladding was then spincoated onto a Si substrate. The Bragg gratings were then imprinted onto the surface of UV15 cladding layer. The waveguide was formed using another polymer (NOA73). A rib waveguide structure was employed for lateral confinement and was also fabricated using soft imprinting. Details of fabrication techniques and optical characterisation are presented.