Abstract

High-gain materials and high-quality structures are the two main conditions that determine the amplification performance of optical waveguides. However, it has been hard to balance each other, to date. In this work, we demonstrate breakthroughs in both glass optical gain and optical waveguide structures. We propose a secondary melting dehydration technique that prepares high-quality Er³⁺–Yb³⁺ co-doped phosphate glass with low absorption loss. Additionally, we propose a femtosecond laser direct-writing technique that allows controlling the cross section, size, and mode field of waveguides written in glass with high accuracy, leveraging submicron-resolution multi-scan direct-writing optical waveguide technology, which is beneficial for reducing insertion loss. As a proof of concept demonstration, we designed and fabricated two kinds of waveguides, namely, LP₀₁- and LP₁₁-mode waveguides in the Er³⁺–Yb³⁺ co-doped phosphate glass, enabling insertion loss as low as 0.9 dB for a waveguide length of 2 mm. Remarkably, we successfully achieved an optical amplification for both the waveguides with a net gain of >7 dB and a net-gain coefficient of >3.5 dB/mm, which is approximately one order of magnitude larger than that in the Er³⁺–Yb³⁺ co-doped phosphate glass fabricated by the traditional melt-quenching method. This will open new avenues toward the development of integrated photonic chips.

© 2023 Optica Publishing Group

High-order mode waveguide amplifier with high mode extinction ratio written in an Er³⁺-doped phosphate glass

Xiangyu Sun, YuYing Wang, Lijing Zhong, Daoyuan Chen, Beibei Xu, Zhijun Ma, Xiaofeng Liu, Giuseppe Barillaro, Zhi Chen, and Jianrong Qiu
Opt. Express 31(4) 5812-5819 (2023)

Broadband 1.0 µm emission in Nd³⁺/Yb³⁺ co-doped phosphate glasses and fibers for photonic applications

Guowu Tang, Xiangyang Song, Dongliang Yang, Minbo Wu, Fangteng Zhang, Weiren Zhao, Qi Qian, and Zhongmin Yang
Opt. Lett. 48(22) 5879-5882 (2023)

On-chip Er-doped Ta₂O₅ waveguide amplifiers with a high internal net gain

Zheng Zhang, Ruixue Liu, Wei Wang, Kunlun Yan, Zhen Yang, Maozhuang Song, Duanduan Wu, Peipeng Xu, Xunsi Wang, and Rongping Wang
Opt. Lett. 48(21) 5799-5802 (2023)

Erbium-ytterbium codoped thin-film lithium niobate integrated waveguide amplifier with a 27 dB internal net gain

Zhihao Zhang, Shanming Li, Renhong Gao, Haisu Zhang, Jintian Lin, Zhiwei Fang, Rongbo Wu, Min Wang, Zhenhua Wang, Yin Hang, and Ya Cheng
Opt. Lett. 48(16) 4344-4347 (2023)

High-Q lasing in Nd³⁺-doped phosphate glass microsphere resonators

Qing Huang, Haizhen Ding, Mingming Zhang, Shengchuang Bai, Shixun Dai, Qiuhua Nie, Lei Wen, and Xunsi Wang
Opt. Lett. 48(11) 3103-3106 (2023)