To enhance the transverse mode instability (TMI) threshold of a fiber oscillator, a novel configuration is presented. In this configuration the oscillator cavity length is considerably reduced and the remaining active fiber is released out of the cavity to absorb the rest of the pump power and amplify the output signal of the cavity. In fiber oscillators, the index gratings generated by both forward and backward propagating signals can interact with light propagating in the backward and forward directions and degrade the output beam quality. In the proposed modified configuration, due to lower intra-cavity forward and backward signal power the index grating is smoothed and the TMI threshold is increased. Experimental results indicate that this modified configuration has a higher TMI threshold than a conventional fiber oscillator. Finally a higher TMI threshold is achieved in the bidirectional pumping scheme of the modified configuration.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/AO.57.005992 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Transverse mode instability (TMI) significantly limits the power scaling of ytterbium-doped fiber lasers. In this Letter, what we believe to be a novel TMI mitigation strategy is proposed and demonstrated in a bidirectional output fiber laser. On the basis of the continuous wave (CW) pump, integrating a quasi-continuous wave (QCW) pump can effectively improve the TMI threshold of the system.
View Article and Find Full Text PDFStimulated Raman scattering (SRS) and transverse mode instability (TMI) effects are crucial limitation factors for further power scaling of high-power fiber amplifiers with near-diffraction-limited beam quality. It is an important research direction to carry out laser system optimization from the perspective of seed construction. In this work, we experimentally investigated the impact of utilizing different seed lasers on the SRS and TMI characteristics in high power ytterbium-doped fiber amplifiers.
View Article and Find Full Text PDFThe photodarkening (PD) and transverse mode instability (TMI) effects are two main factors limiting the power increase and long-term stability of high-power fiber lasers. A prolonged burn-in test for an all-fiber laser oscillator below the TMI threshold was carried out. We observed the PD-induced TMI effects, which manifested as a sudden decrease in the output power due to higher-order mode leakage.
View Article and Find Full Text PDFTheoretical Study on Transverse Mode Instability in Raman Fiber Amplifiers Considering Mode Excitation.
Micromachines (Basel)
October 2024
College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China.
Article Synopsis
- Raman fiber lasers (RFLs) utilize the stimulated Raman scattering effect to create laser beams with benefits like adjustable wavelengths and low quantum defects, but increased power leads to significant heat generation.
- This heat can cause transverse mode instability (TMI), making it a key obstacle in enhancing RFL performance.
- The study presents a static model for TMI in high-power Raman fiber amplifiers, exploring various factors that influence TMI threshold power and establishing a formula that aids in understanding and mitigating TMI.
We demonstrate new, large-mode area (LMA) gain fibers with ∼25 µm mode-field diameter, and increased higher-order mode loss that enable diffraction limited, pulsed fiber lasers operating at high average power with high pulse energy. We achieved 1.6 mJ, ns pulses, with 1.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!