(S plus C)-band polymer waveguide amplifier based on Tm3+and Er3+layer-doped core-shell nanoparticles

Optical waveguide amplifiers are essential devices in inte-grated optical systems. Their gain bandwidths directly determine the operating wavelength of optical circuits. Due to the difficulty of developing wideband gain media, it has been a challenge to fabricate devices with broad-band amplification capability, resulting in few reports on multi-band polymer waveguide amplifiers. Here, a polymer waveguide amplifier is demonstrated, which achieves loss compensation covering the whole (S + C) band by using NaYF4:Tm,Yb@NaYF4@NaYF4:Er nanoparticles (NPs) -doped SU-8 as the gain medium. The NPs with a layer-doped core-multishell structure not only provided two emitters required for (S + C)-band amplification, but also reduced the energy transfer (ET) between them. Under 980-nm exci-tation, the full width at half maximum (FWHM) of the emission peak of NPs reached 119 nm, and the relative gain in the (S + C) band was about 6-8 dB, successfully expanding the operating wavelength from single-band to multi-band.(c) 2023 Optica Publishing Group