Formation of waveguides in crystalline organic N-benzyl-2-methyl-4-nitroaniline thin films using femtosecond laser ablation process

Abstract

This paper reports the feasibility of femtosecond laser etching of microstructures directly onto crystalline N-benzyl-2-methyl-4-nitroaniline (BNA) films grown on glass to realize single crystal BNA waveguides. The threshold fluence has been estimated and fluence range of 318.5–1274 mJ/cm2 at 800 nm is used for ablation. Holes with diameter ranging from 13 to 26 μm and waveguide patterns with width of 100 μm are demonstrated. Grooves with laser transit gap <20 μm is used to form smaller waveguides. Input faces of the waveguides have been simultaneously irradiated with red laser of 630 nm. The optical image of transmission confirms the wave-guiding. This study shows the feasibility of laser-etching waveguides on crystalline BNA films.