Fabrication of gratings with moire fringes and their application to solid-state dye laser

Abstract

A moire pattern appears when two or more periodic patterns are superimposed with a small rotation angle. We focused on this phenomenon and fabricated moire gratings by an etchless process. This process utilizes two-beam interference exposure with a He-Cd laser to fabricate holographic gratings quickly and at low cost. Experimental results show that the moire gratings had a diffraction efficiency sufficient to allow them to serve as resonators for DFB solid-state dye lasers. We then prepared a DFB solid-state dye laser device with moire gratings and pumped the device with a second harmonic generation (SHG) of a Nd:YAG laser. This resulted in narrow-banded DFB laser oscillation in the red wavelength region.