Effect of silver nanoparticles on the optical amplification of lead germanium oxide glasses doped with Nd3+

The effect of silver nanoparticles on the optical amplification of lead germanium oxide glasses (PbO-GeO2) doped with Nd3+ is presented in this work. Infrared photoluminescence at 1064 nm is investigated with the excitation made with a continuous-wave diode laser operating at 808 nm, in resonance with the Nd3+ transition (4 I9/2/4 F5/2). Growth of $\sim 100$% in the photoluminescence intensity is observed in comparison with the reference sample without silver nanoparticles. Optical gain measurements using 2 mm thick samples are performed with a probe beam at 1064 nm and the pump beam at 808 nm. Gain of 2.5 dB/cm in the presence of metallic nanoparticles was measured when the pump laser power was of 1.0 W. The contribution of silver nanoparticles to the gain enhancement was of 100% and was correlated to the photoluminescence enhancement attributed to the increased local field produced by the metallic nanoparticles. The present study shows that PbO-GeO2 glasses containing Nd3+ and silver nanoparticles are potential candidates to be used in optical amplifiers at 1064 nm. Moreover, it demonstrates the possibility to perform light guiding and evaluate the optical gain performance before the construction of the photonic device using glasses fabricated with the melt quenching technique which is simple and cheap.