Invited Conference Paper at Photonics West 2015, San Francisco
Patricia Scully and Walter Perrie
“Towards 3-D laser nano patterning in polymer optical materials,”
presented 12 February at Photonics West SPIE LASE at Conference 9351: Laser-based Micro- and Nanoprocessing IX, 7 – 12 February 2015, San Francisco, California United States. 30 minutes
Progress towards 3-D subsurface structuring of polymers using femtosecond lasers is presented. Highly localised refractive index changes can be generated deep in transparent optical polymers without pre doping for photo-sensitisation or post processing by annealing. Understanding the writing conditions surpasses the limitations of materials, dimensions and chemistry, to facilitate unique structures entirely formed by laser-polymeric interactions to overcome materials, dimensional, refractive index and wavelength constraints. Numerical aperture, fluence, temporal pulselength, wavelength and incident polarisation are important parameters to be considered, in achieving the desired inscription. Non-linear aspects of multiphoton absorption, plasma generation, filamentation and effects of incident polarisation on the writing conditions will be presented.
Keywords: Femtosecond laser, polymer, PMMA, refractive index, nanostructure, waveguide, volume Bragg grating, spatial light modulator.