Researchers from National Sun Yat-sen University and National Tsing Hua University in Taiwan, along with collaborators from Egypt, have made significant strides in the field of fiber lasers. Their work focuses on achieving optical bistability in an erbium-doped fiber laser (EDFL) using a novel saturable absorber (SA).
The team, led by Dr. Chao-Kuei Lee and Dr. Shiao-Wei Kuo, utilized a covalent organic framework (COF) SA with low saturation intensity. This innovative approach allowed them to observe optical bistability, a phenomenon where a system exhibits two stable output states for a given input. The researchers identified two distinct bistability regions within the EDFL. Notably, they observed a direct transition from mode-locking to non-lasing states during a pump down-sweep, a behavior not previously reported in EDFL studies.
The study also revealed stable soliton-like pulses and stepwise pulse-number hysteresis, indicating dynamics akin to a first-order phase transition. These findings suggest that low-saturation intensity SAs can facilitate bistability-assisted pulse formation in fiber lasers, offering a compact and efficient solution for pulse generation.
The research, titled “Optical bistability of continuous-wave and multi-pulse phase transition within EDFL via low threshold saturable absorber,” was published in the journal Optics Express. This work holds practical implications for the energy sector, particularly in the development of advanced laser systems for various applications, including telecommunications, sensing, and precision manufacturing. By enabling more efficient and controllable pulse generation, this technology can contribute to advancements in energy-efficient communication networks and industrial processes.
The researchers’ innovative use of COF SAs represents a significant step forward in the field of fiber lasers, with potential applications that extend beyond the energy sector into areas such as medical diagnostics and environmental monitoring. Their work underscores the importance of continued research and development in photonic technologies to drive progress in various industries.
This article is based on research available at arXiv.