Optical MNFs are tube-shaped optical waveguides with measurements beneath or near the frequency of the light. Since its most memorable exploratory show, low-misfortune silica MNF has been drawing expanding consideration in wide applications from optical sensors, molecule optics, nonlinear optics, and optomechanics.
By and large, expanding the waveguiding mode power is the best way to deal with improving light-matter connection and investigate new open doors for both logical exploration and mechanical applications. However, the most powerful CW mode power ever recorded in a MNF is less than 0.4 W, and the typical waveguiding power is less than 0.1 W (in CW or averaged power). Additionally, it is unknown how much power a MNF can transmit or the optical damage threshold.
In another paper distributed in Light Science and Application, a group of researchers, led by Prof. Limin Tong and Assoc. In an optical MNF around 1,550 nm wavelength, Prof. Xin Guo from Zhejiang University, China, and Dr. Yuhang Li from Tsinghua University, China, demonstrated high-power CW optical waveguiding with power up to 13 W, which is more than 30 times higher than the highest power reported previously.
“Because CW waveguiding is desired in a wide range of MNF-based applications, our findings may extend MNF optics into the high-power region, opening up new opportunities for MNF-based technology ranging from fiber lasers, nonlinear conversion, optomechanics, biophotonics, and atom optics,”
A team of scientists, led by Prof. Limin Tong and Assoc. Prof. Xin Guo from Zhejiang University, China, and Dr. Yuhang Li from Tsinghua University, China,
They demonstrate that the MNF maintains its high optical transmittance (> 95 percent) while waveguiding such high-power CW without the presence of predominant single scattering spots on the fiber surface. During a two-month test, the MNF was able to safely handle a CW power greater than 10 W with no observable degradation after more than 10 hours of operation. In view of the retention-prompted warm impact, they foresee an optical harm edge higher than 70 W (in CW power) in a solitary MNF in the air.
The team uses high-speed optomechanical driving of a microdroplet (10 m) in the air to demonstrate the extraordinary capability of a high-power waveguiding MNF. The droplet can be driven more than ten times faster than in previous MNF-based optomechanics systems, as shown by the measured power-dependent droplet velocity vo (e.g., vo = 2.1 mm s-1 at a waveguided power of 2.2 W).
Time-sequential optical microscope images of an oil droplet moving along a MNF with a diameter of one millimeter From left to right, the MNF is waveguided by a light with 0.7 W power. b. The power-dependent velocity of the oil droplet in the MNF that is being driven by the waveguiding light was measured (blue squares) and fitted (black line). c, Dependence of the output power (PHG) of THG or SHG on the waveguided power (Pin), a close-up of the droplet velocity with waveguided power below 0.5 W ξ, transformation effectiveness of symphonious age. Credit: Jianbin Zhang, Yi Kang, Xin Guo, Yuhang Li, Keying Liu, Yu Xie, Hao Wu, Dawei Cai, Jue Gong, Zhangxing Shi, Yingying Jin, Pan Wang, Wei Fang, Lei Zhang, and Limin Tong.
Also achieve intermodal-phase-matched second harmonic generation with an efficiency that is higher than that of short pulse generation and third harmonic generation with an efficiency that is within the range of typical results that have
“High waveguiding power, perfectly matched phase, and a relatively long interaction length all contribute to the extraordinary CW conversion efficiency.” They add, “The nonlinear frequency conversion efficiency could be even higher when higher CW waveguiding power is available because the power we used here is lower than the optical damage threshold (70 W).”
“Our results may extend MNF optics into the high-power region and open up new opportunities for MNF-based technology ranging from fiber laser, nonlinear conversion, optomechanics, biophotonics, and atom optics,” the researchers suggest. “As CW waveguiding is desired in a variety of MNF-based applications,” they add,
More information: Jianbin Zhang et al, High-power continuous-wave optical waveguiding in a silica micro/nanofibre, Light: Science & Applications (2023). DOI: 10.1038/s41377-023-01109-2
