Ultrafast laser plasma doping of Er3+ in Si3N4-on-silicon

An ultrafast laser plasma doping (ULPD) technique is used to dope Er3+ into silicon nitride (Si3N4)-on-silicon substrate. An adjustable refractive index (1.9-2.9) makes silicon nitride a highly suitable candidate for erbium-doped waveguide amplifier (EDWA) applications. The resultant layers consist of a mixture of target glass with Si3N4 and the structural and optical properties are varied according to fs-laser energy used. The use of higher fs-laser energy caused the formation of a thicker doped layer on Si3N4, predominantly with target material elements. However, surface doped layers were rougher when higher fs-laser energies were used. The doped layer exhibits spectroscopic characteristics of erbium with photoluminescence lifetimes varying from 3.95 to 9.59 ms..