In this paper, we propose an all-normal-dispersion ytterbium-fiber laser with a novel ring cavity architecture having two nonlinear amplifying loop mirrors (NALM) as saturable absorbers, capable of delivering distinctly different pulses with adjustable features. By optimizing the loop lengths of the individual NALMs, the cavity can be operated to deliver Q-switched mode-locked (Q-ML) pulse bunches with adjustable repetition rates, mode-locked pulses in dissipative soliton resonance (DSR) regime or noise-like pulse (NLP) regime with tunable pulse width. The DSR pulses exhibit characteristic narrowband spectrum, while the NLPs exhibit large broadband spectrum. The operation regime of the laser can be controlled by adjusting the amplifier pump powers and the polarization controllers. To the best of the authors' knowledge, this is the first demonstration of a single mode-locked cavity where narrowband DSR pulses and broadband NLPs alongside Q-ML pulse bunches can be selectively generated by employing two NALMs.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/AO.57.001225 | DOI Listing |
We propose and demonstrate, for the first time to the best of our knowledge, an all-polarization-maintaining (all-PM) dual-comb Er-fiber laser based on combined figure-8 and figure-9 architectures. The opposite signs of the non-reciprocal phase shifts required for figure-8 and figure-9 architectures in the shared nonlinear amplifying loop mirror (NALM) are achieved using a single non-reciprocal phase shifter (NRPS) that operates in two orthogonal polarizations. The capability of common mode noise cancellation, environmental stability, long-term reliability, and the tunable range of the repetition rate difference Δ between two combs has been investigated and characterized.
View Article and Find Full Text PDFWe propose and demonstrate an ultra-wide tunable mode-locked all-fiber laser based on nonlinear amplifying loop mirror (NALM) with the output of cylindrical vector beams (CVBs). The tuning range covers from 1029 nm to 1098 nm through the intracavity nonlinear polarization evolution (NPE) filter effect. The switchable CVBs between radially and azimuthally polarized beams with mode purity above 90% are generated by incorporating a broadband few-mode long-period fiber grating (LPFG).
View Article and Find Full Text PDFThe flat-top beams have significant potential for applications in micromachining and biomedicine, due to their unique intensity distribution. Therefore, spatiotemporal flat-top beams, which are all flat-top in both spatial and time domains, may significantly advance its development. Here, we demonstrate the generation of a spatiotemporal flat-top beam using an all-fiber mode-locked laser.
View Article and Find Full Text PDFAnn Hepatol
January 2025
Department of Gastroenterology, Xinhua Hospital of zhejiang Province: The Second Affiliated Hospital of Zhejiang Chinese Medical University, Zhejiang, China. Electronic address:
Non-alcoholic fatty liver disease (NAFLD), now recognized as metabolic dysfunction-associated steatotic liver disease (MASLD), represents a significant and escalating global health challenge. Its prevalence is intricately linked to obesity, insulin resistance, and other components of the metabolic syndrome. As our comprehension of MASLD deepens, it has become evident that this condition extends beyond the liver, embodying a complex, multi-systemic disease with hepatic manifestations that mirror the broader metabolic landscape.
View Article and Find Full Text PDFFEBS J
January 2025
Physics, Department of Molecular and Translational Medicine, University of Brescia, Italy.
Neutrophil elastase (NE) is released by activated neutrophils during an inflammatory response and exerts proteolytic activity on elastin and other extracellular matrix components. This protease is rapidly inhibited by the plasma serine protease inhibitor alpha-1-antitrypsin (AAT), and the importance of this protective activity on lung tissue is highlighted by the development of early onset emphysema in individuals with AAT deficiency. As a serpin, AAT presents a surface-exposed reactive centre loop (RCL) whose sequence mirrors the target protease specificity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!