Abstract Spatiotemporal mode‐locking (STML) in fiber lasers are of interest applications such as optical communications, nonlinear imaging, and precision machining. To date, STML the near‐infrared region have been well demonstrated, yet operation at visible wavelengths is still challenging. Here, a picosecond laser 635 nm with implementation Pr/Yb co‐doped few‐mode polarization rotation technology reported. By solving modified generalized multimode Schrödinger equation, formation...

Abstract Photocatalytic seawater splitting is an attractive way for producing green hydrogen. Significant progresses have been made recently in catalytic efficiencies, but the activity of catalysts can only maintain stable about 10 h. Here, we develop a vacancy-engineered Ag 3 PO 4 /CdS porous microreactor chip photocatalyst, operating with performance stability exceeding 300 This achieved by establishment both selectivity impurity ions and tailored interactions between vacancies sulfur...

In this paper, the phenomenon of reverse saturable absorption offset-spliced graded index multimode fibers (OS-GIMF) is revealed. And based on that, stable square-shaped and chair-like mode-locked pulses are demonstrated with maximum pulse energy 0.14 µJ 23.8 nJ respectively, while OS-GIMF acts as a absorber (SA) in fiber laser. By adjusting polarization controller (PC) pump power, can be switched to each other. This SA could sever high power light source owing its damage threshold, compact...

We report, to the best of our knowledge, first visible-wavelength all-fiber passively mode-locked vortex laser by a figure-9 cavity in combination with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula> 635 nm mode selective coupler, which can deliver picosecond optical pulses topological charges OAM notation="LaTeX">$_{\pm 1}$</tex-math></inline-formula> . The emits stable...

Heterojunction photocatalysts have attracted tremendous attention because of their great potential for addressing worldwide energy and environmental issues. In the evolution heterojunction from bulk to atomic scale, thin-layered exhibit better photocatalytic properties but at cost a weak built-in electric field insufficient stability long-term reaction. Therefore, development more advanced heterojunctions is fundamentally important. A with thickness within space charge region has been...

Dual-color mode-locked fiber lasers are widely applied in various domains, including difference-frequency generation, Raman scattering spectroscopy, and microscopy. A dual-color laser can be obtained through a shared main path along with dedicated subpaths, which pumps either single or multiple gain media, offering more flexible design simpler structural configuration. In this Letter, we demonstrated dual-repetition rate of 1.3/1.4 µ m based on nonlinear polarization rotation (NPR)...

This paper proposes an amplitude modulation method based on synthetic wavelength to directly acquire the vibration waveform of targets in a self-mixing interferometry (SMI) system. The target is extracted from envelope amplitude-modulated SMI signal, which arises differential wavelength. Experimentally, with different frequencies were measured, demonstrating average frequency measurement error 0.6% and coefficient determination 0.9938 for agreement. first time, best our knowledge, field...

Vibrational spectroscopy, including Raman scattering and infrared (IR) absorption, provides essential molecular fingerprint information, facilitating diverse applications, such as interfacial sensing, chemical analysis, biomedical diagnostics. The complementary selection rules of IR spectroscopies offer distinct, yet mutually reinforcing, insights into structure dynamics. However, in dynamic or complex environments, either technique alone is not capable providing a complete nuanced picture...

Visible random fiber lasers have garnered significant attention due to their unique emission properties and potential applications in various fields. We first, the best of our knowledge, demonstrated a compact all-fiber structure, red wavelength, laser (RFL) based on double-clad Pr-doped ZBLAN fiber. The simple half-open cavity consists high-reflectivity pigtail mirror not only served as gain medium but also offered backward scattering. investigated effects different lengths output power...

We report, to the best of our knowledge, first demonstration an O + E-band tunable watt-level bismuth-doped phosphosilicate fiber laser and its frequency doubling red laser. Benefiting from two types bismuth active centers associated with silicon phosphorus introduced in one fiber, ultrabroad gain is available designed low-water-peak (Bi-PSF) pumped by a self-made 1239 nm Raman The high-efficiency lasing achieved maximum output power 1.705 W around 1320 slope efficiency 33.0%. wavelength can...

Random fiber lasers are of tremendous interest to diverse applications for optical sensing, speckle-free imaging. To date, random with fundamental mode oscillation have been well developed. However, controllable oscillating spatial in not reported yet. Here, we propose and demonstrate a few-mode laser switchable based on injection locking. An external signal light is injected realize the locking transverse this direct oscillations mode, hybrid high order can be realized, respectively. This...

High-energy pulsed lasers in the green spectral region are of tremendous interest for applications space laser ranging, underwater detection, precise processing, and scientific research. Semiconductor currently difficult to access so-called “green gap,” high-energy still heavily rely on nonlinear frequency conversion near-IR lasers, precluding compact low-cost systems. Here, we address this challenge by demonstrating, first time best our knowledge, millijoule-level pulses generated directly...

We report the 1.3/1.4 µm dual-wave band dissipative soliton resonance (DSR) in a passively mode-locked bismuth-doped phosphosilicate fiber (Bi-PSF) laser. The low-water-peak Bi-PSF with two bismuth active centers associated silicon and phosphorus supports O+E-band gain. Using 1239 nm home-made Raman laser as pump source nonlinear amplifying loop mirror for initiating mode-locking, stable DSR operation at 1343 1406 is achieved spectral bandwidth of 12 16 nm. pulse duration power increases...

In this letter, we report a 488 nm blue picosecond pulse generation by frequency doubling of homemade 977 watt-level all polarization maintaining mode-locked fiber laser. Based on SESAM passively Yb-doped linear cavity configuration, the seed laser shows 977.84 central wavelength, 0.13 spectral width, 12.94 ps duration, 76.09 MHz repetition rate, and 5.12 mW average power, respectively. The power is further scaled up to 2.06 W adopting an all-fiber MOPA structure, duration width are slightly...

We have successfully generated a 1.3/1.4 µm random fiber laser (RFL) using bismuth (Bi)-doped phosphosilicate fiber. The Bi-doped RFL has shown excellent long-term operational stability with standard deviation of approximately 0.34% over 1 h at maximum output power 549.30 mW, slope efficiency 29.21%. offers an emission spectrum ranging from 1.28 to 1.57 µm, indicating that it can be tuned within this band. Here, we demonstrated wavelength-tuning wavelength achieved through the Bragg grating...

In this paper, we propose a stable orbital angular momentum (OAM) mode fiber laser with an all-polarization-maintaining (PMF) structure based on combination of two linearly polarized modes. The intensity ratio between the modes can be adjusted by adopting double-pump structure. A pair polarization-maintaining long-period gratings (PM-LPFGs) are used as converter. number topological charges OAM beam tuned +1 and -1 stretching fiber. By all-PMF structure, build without polarization controller...