Investigation of the net gain behavior in Er:Ti:LiNbO3 waveguide amplifier by an erbium-doped As2S3 and undoped As2S3 overlay

In this work the fabrication and characterization of As2S3 and erbium-doped As2S3 layers on Er:Ti:LiNbO3 channel waveguide amplifiers are reported and compared with Er:Ti:LiNbO3 channel amplifier for the first time to the author's knowledge. We have first characterized a typical Er:Ti:LiNbO3 waveguide amplifier of 2.6 cm length and measured a small signal net gain of 2.5 dB for TM mode under 1470 nm pumping. Further optical characterization of Er:Ti:LiNbO3 case was also performed for two wavelengths of 1531 and 1550 nm in an Er:Ti:LiNbO3 case of 3.5 cm length. Signal enhancement of 22.234 and 6.463 dB was obtained for two wavelengths respectively and showed a stability behavior for an incident pump power of about 144 mW. As2S3 layer and erbium doped As2S3 waveguide layer were deposited by thermal and co-sputtering respectively on two Er:Ti:LiNbO3 channel waveguide amplifiers as hybrid waveguide amplifiers then absorption and amplification were characterized. Whilst net gain was not improved due to the presence of pump-induced up-converted green light and moisture diffused in overlay waveguides, this nonetheless represents a further step towards the realization of hybrid waveguide amplifiers with loss compensation in nonlinear photonics.

Automated summary

The fabrication and characterization of As2S3 and erbium-doped As2S3 layers on Er:Ti:LiNbO3 channel waveguide amplifiers were reported and compared with Er:Ti:LiNbO3 channel amplifier for the first time. Despite the lack of improvement in net gain due to the presence of pump-induced up-converted green light and moisture diffused in overlay waveguides, this work represents a step towards the realization of hybrid waveguide amplifiers with loss compensation in nonlinear photonics.