Polymer-based Waveguide Amplifiers Research Articles

Effect of inorganic compound size on the relative gain of polymer-based optical waveguide amplifiers

Polymer based waveguide amplifiers are the key devices to improve the performance of integrated communication systems. However, due to their comparatively low relative gain, their widespread practical application has been limited. In polymer based optical waveguide amplifiers, the size of inorganic compounds in the composite gain media has a significant impact on the gain performance of the amplifier. Up to now, there has been limited research on the size influence of inorganic compound on the gain variation in organic polymer based optical waveguide amplifiers. In this study, a series of NaLu0.8-xYxF4: Yb, Er-PMMA composite polymer were used as gain media to prepare organic waveguide amplifiers working in the C-band (1530–1565 nm). The size of NaLu0.8-xYxF4: Yb, Er compounds varies between 20 nm and 150 nm. In the polymer based optical waveguide amplifiers, variations in the size of the inorganic NaLu0.8-xYxF4:Yb,Er compound affects not only the C-band emission intensity but also the relative gain. When the size of the inorganic compound is 65 nm, the composite gain media exhibits the maximum emission peak intensity at 1550 nm and the corresponding device achieves a maximum relative gain of 19.3 dB/cm. Our results show that the size of inorganic compounds affects the variation of luminescence intensity and ultimately the gain of waveguide amplifiers. The gain of future polymer optical waveguide amplifiers can be improved by this method.

Introduce Ce3+ Ions to Realize Enhancement of C+L Band Luminescence of KMnF3: Yb, Er Nanoparticles.

Polymer-based waveguide amplifiers are essential components in integrated optical systems, as their gain bandwidths directly determine the operating wavelength of optical circuits. However, development of the wideband gain media has been challenging, making it difficult to fabricate devices with broadband amplification capability. Rare earth ion-doped nanoparticles (NPs) are a key component in the gain media, and their full width at half maximum (FWHM) of the emission peak decides the final gain bandwidth of the gain media. Here, KMnF3: Yb, Er, Ce@KMnF3: Yb NPs with the broad full width at half maximum (FWHM) of the emission peak covering the S+C band was prepared. The NPs were synthesized using a hydrothermal method, and the FWHM of the emission peak of NPs reached 76 nm under the excitation of a 980 nm laser. The introduction of Ce3+ ions and a core-shell structure coating greatly enhanced the emission intensity of NPs at C band. Since KMnF3: Yb, Er, Ce@KMnF3: Yb NPs have exceptional broadband luminescence properties at C band, KMnF3: Yb, Er, Ce@KMnF3: Yb NPs can be the potential gain medium in the future polymer-based waveguide amplifiers.

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.

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.

Great enhancement of relative gain in polymer waveguide amplifier using NaYF4/NaLuF4:Yb,Er-PMMA nanocomposite as gain media

Polymer-based waveguide amplifiers were the key devices in short-distance optical communication systems. However, the low relative gain of these amplifiers hindered their practical applications. Here, we introduced a kind of waveguide amplifier devices affording higher relative gain, which were using a new nanocomposite as gain media. The nanocomposite was synthesized by copolymerization of the methyl methacrylate (MMA) monomers with the unsaturated organic ligand-modified core-shell rare earth nanoparticles (NPs). Due to the formation of chemical bonds between the NPs and the polymer matrix, the dispersion of NPs and the stability of the nanocomposite were both greatly improved. Therefore, using this nanocomposite as gain media, in a 15 mm long embedded rectangular waveguide, a really high relative gain of 27 dB at 1535 nm with the 980 nm laser pump was observed, which was nearly three times higher than that in our previous work. Owing to its good performance, the nanocomposite could play an important role in the future optical communication technology.

High-gain polymer optical waveguide amplifiers based on core-shell NaYF4/NaLuF4: Yb3+, Er3+ NPs-PMMA covalent-linking nanocomposites.

Waveguide amplifiers have always been significant key components for optical communication. Unfortunately, the low concentration of rare earth ions doped in the host material and the inadequate optimization of the waveguide structure have been the common bottleneck limitations. Here, a novel material, NaYF4/NaLuF4: 20% Yb3+, 2% Er3+ nanoparticle-Polymeric Methyl Methacrylate covalent-linking nanocomposite, was synthesized. The concentrations of Er3+ and Yb3+ doping increased an order of magnitude. Under a 980 nm laser excitation, highly efficient emission at 1.53 μm was obtained. The characteristic parameters of the single mode waveguide were carefully designed and optimized by using a finite difference method. A formulized iteration method is presented for solving the rate equations and the propagation equations of the EYCDWA, and both the steady state behavior and the gain were numerically simulated. The optimal Er3+ and Yb3+ concentrations are 2.8 × 1026 m−3 and 2.8 × 1027 m−3, and the optimal waveguide length is 1.3 cm. Both theoretical and experimental results indicated that, for an input signal power of 0.1 mW and a pump power of 400 mW, a net gain of 15.1 dB at 1530 nm is demonstrated. This result is the highest gain ever reported in polymer-based waveguide amplifiers doped with inorganic Er3+-Yb3+ codoped nanocrystals.

KMnF3:Yb3+,Er3+@KMnF3:Yb3+ active-core–active-shell nanoparticles with enhanced red up-conversion fluorescence for polymer-based waveguide amplifiers operating at 650 nm

We demonstrated optical amplification at 650 nm in KMnF3:Yb3+,Er3+@KMnF3:Yb3+ nanoparticles doped polymer waveguides for the first time.

Sub-10 nm BaYF5:Yb3+,Er3+ core–shell nanoparticles with intense 1.53 μm fluorescence for polymer-based waveguide amplifiers

Sub-10 nm BaYF5:Yb3+,Er3+ core–shell nanoparticles (NPs) were synthesized by a high boiling solvent process. Under a 980 nm laser excitation, up- and down-conversion fluorescence spectra from BaYF5:Yb3+,Er3+ NPs were recorded and analyzed. After coating the active-shell (containing Yb3+ ions) around the BaYF5:Yb3+,Er3+ NPs, the intensity of the 1.53 μm fluorescent band was enhanced by 11 times owing to surface passivation effect and efficient energy transfer between Yb3+ ions in active-shell and Er3+ ions. Furthermore, the NPs showed excellent redispersibility in common nonpolar solvents. By dispersing BaYF5:Yb3+,Er3+ active-core–active-shell NPs into an SU-8 2005 polymer, we constructed polymer-based optical waveguide amplifiers and measured their performance. For an input signal power of 0.1 mW and a pump power of 200 mW, a relative optical gain of ∼6.3 dB was obtained at 1535 nm in a 13 mm-long waveguide.

Hybrid polymer-based waveguide amplifiers

Hybrid polymer-based waveguide amplifiers