Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.

We demonstrate tunable mid-infrared (MIR) Raman soliton generation in an all-solid fluorotellurite fiber pumped by a 1960 nm femtosecond fiber laser. All-solid fluorotellurite fibers are fabricated by using a rod-in-tube method. The core and cladding materials are TeO₂-BaF₂-Y₂O₃ (TBY) and AlF₃-based glasses. Since the refractive index of AlF₃-based glass is much lower than that of TBY glass, the zero-dispersion wavelength of all-solid fluorotellurite fiber can be tuned in a wide range by simply varying the core diameter of the fiber. By using a 0.5 m long all-solid fluorotellurite fiber with a core diameter of ∼ 2.7 μm as the nonlinear medium and a 1960 nm femtosecond fiber laser as the pump source, tunable MIR Raman soliton generation from 1.96 to 2.82 μm is obtained via soliton self-frequency shift by increasing the pump power. For the soliton laser source operating at 2.82 μm, the obtained optical-to-optical conversion efficiency is about 18% and the calculated pulse width is about 93 fs. Our results show that all-solid fluorotellurite fibers are promising nonlinear media for constructing tunable MIR ultrafast laser sources.

In this paper, a low-power 1 × 2 polymeric thermo-optic switch operating at the polymer optical fiber low-loss window of 650 nm was studied. The characteristic parameters of the switch were carefully designed and simulated. The fabrication was done by using standard semiconductor fabrication techniques such as spin-coating, photolithography, and dry etching. The device was fabricated based on poly(methyl methacrylate) (PMMA)-based materials with the Mach-Zehnder interferometer (MZI) structure. The device shows an extinction ratio of over 23.4 dB at 650 nm with a very low-power consumption of 5.3 mW. The measured switching rise time and fall time are 464.4 and 448.0 µs, respectively.

Mode-division multiplexing (MDM) is a new method of space-division multiplexing (SDM) that can break through the limitation of single-mode transmission capacity and greatly improve the capacity of optical fiber communication. In the case of a few-mode (FM) system, it is possible that each mode can carry its own data steam and transmit long distances owing to a few-mode erbium-doped fiber amplifier (FM-EDFA). In addition, an Er ³⁺ -Yb ³⁺ co-doped waveguide amplifier (EYCDWA) based on polymer materials has numerous advantages of miniaturization and flexibility in planar integrated optics compared with the EDFA. This study explored the theory of a few-mode Er ³⁺ -Yb ³⁺ co-doped waveguide amplifier (FM-EYCDWA) and established a theoretical model of an FM-EYCDWA with a novel modified overlap integral factor. The differential modal gain (DMG) of the FM-EYCDWA can be reduced or even eliminated by equalizing the modified overlap integral factor of each signal mode. An unprecedented doping configuration adapted to the fabrication process of an optical waveguide was proposed to fill the gap between modal gains, which can be optimized by a genetic algorithm (GA). We investigated two optimization cases of three-mode and five-mode group FM-EYCDWAs to verify the validity of the theoretical model; both cases were optimized to minimize the DMGs under the same limitations, and excellent performance was presented, which demonstrated that the design method of the few-mode amplifiers we presented can offer a referable guideline.

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 N a Y F 4 : E r 3 + Y b 3 + 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.

We demonstrated optical amplification in BaYF₅: 20% Yb³⁺, 2% Er³⁺ (BYF) nanocrystals doped polymer waveguide. BYF nanocrystals with an average size of ∼13 nm were synthesized by a high‐boiling solvent process. Intense 1.53 μm fluorescence was obtained in the nanocrystals under excitation at 980 nm. An optical polymer waveguide was fabricated by using BYF nanocrystals doped SU‐8 polymer as the core material. A relative optical gain of ∼10.4 dB at 1525 nm was achieved in a 1.1 cm long waveguide for an input signal power of ∼0.09 mW and a pump power of ∼212 mW.