Gain enhancement technique for S-band polymer-based waveguide amplifiers.

The S-band polymer-based waveguide amplifier has been fabricated, but how to improve the gain performance remains a big challenge. Here, using the technique of establishing the energy transfer between different ions, we successfully improved the efficiency of Tm3+:3F3→3H4 and 3H5→3F4 transitions, resulting in the emission enhancement at 1480 nm and gain improvement in S-band. By doping the NaYF4:Tm,Yb,Ce@NaYF4 nanoparticles into the core layer, the polymer-based waveguide amplifier provided a maximum gain of 12.7 dB at 1480 nm, which was 6 dB higher than previous work. Our results indicated that the gain enhancement technique significantly improved the S-band gain performance and provided guidance for even other communication bands.

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

Optical waveguide amplifiers are essential devices in integrated 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 broadband 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 excitation, 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.

Polymer-based S-band waveguide amplifier using NaYF4:Yb,Tm-PMMA nanocomposite as gain medium.

Optical waveguide amplifiers are essential to improve the performance of integrated communication systems. Previous research has mainly focused on C- and L-bands amplification, but there are few reports on S-band waveguide amplifiers. Here, we introduce a polymer-based waveguide amplifier that uses a NaYF4:Yb3+,Tm3+ nanoparticles-PMMA nanocomposite as gain medium, which can provide loss compensation in the S-band. To obtain the strongest emission luminescence at 1480 nm, we optimized the doping concentration of Yb3+ and Tm3+ to 20% and 1%, respectively. By copolymerizing the nanoparticles and methyl methacrylate monomers, the nanocomposite was synthesized and used as the gain medium to fabricate S-band waveguide amplifiers. A relative gain of 5.6 dB/cm was observed at 1480 nm under the excitation of a 980-nm pump laser. To the best of our knowledge, this is the first time that S-band amplification has been observed in a polymer-based waveguide amplifier. This result is expected to extend the waveband of polymer-based waveguide amplifiers to the S-band.

Polymer/silica hybrid waveguide amplifier at 532 nm based on NaYF4:Er3+, Yb3+ nanocrystals.

An optical waveguide amplifier, which can solve the problem of optical attenuation in optical network transmission, is the key technology to solve optical chip integration and optical interconnection. Here, to the best of our knowledge, we propose a novel polymer/silica hybrid waveguide amplifier at 532 nm for the first time. The research is of great significance to the improvement of short distance communication and visible light communication system. The waveguide amplifier was designed as an embedded structure based on NaYF4:Er3+Yb3+ nanocrystals, which were synthesized by high-temperature thermal decomposition. When the input signal power was 0.1 mW, and the pump power was 300 mW, a relative gain of 4.3 dB was obtained on an 8 mm waveguide. This result is of great research significance to break the distance limit and make all-optical transmission a reality.