Transmission properties of hydrogen and helium ion implantation induced waveguide grating structures and potential application

Optical waveguides in fused silica have been manufactured by H+ implantation, which shows significantly improved transmission properties after implantation. The relationship between the transmission property and the thickness of the cladding layer after surface etching has also been investigated. Grating structures in waveguides have been made by additional He+ implantation with a periodic metal mask covering the surface. The transmission of such grating structures is leveled throughout the measured wavelength range. This observation suggests a new method to make variable optical attenuators (VOAs) to equalize optical powers of different channels.