Laser performance of Tm:(LuGd)GaO crystal in 2-2.3 μm spectral region.

Continuous-wave (CW) and acousto-optic (AO) Q-switched laser operations based on Tm:LGGG crystal have been investigated in the spectral region of 2-2.3 μm. In CW regime, laser emissions at 2006 nm, 2160 nm, and 2344 nm are obtained by using different cavity mirrors with selective coating.

Megawatt peak power, repetition rate tunable, high beam quality nanosecond QCW-LD end-pumped Nd:YVO MOPA system.

A megawatt (MW) peak power, tunable repetition rate nanosecond (ns) laser system based on a quasi-continuous wave (QCW) laser diode (LD) end-pumped master oscillator power amplifier (MOPA) structure was demonstrated. A 1064 nm electro-optically Q-switched Nd:YVO laser was used as the seed source, generating a pulse duration of 4.6 ns, a single pulse energy of 530 μJ, a repetition rate of 1 kHz, and beam quality factors of  = 1.

Large energy, narrow bandwidth 1550 nm picosecond polarization-maintaining fiber laser.

A large energy, narrow bandwidth picosecond polarization-maintaining fiber laser operating at 1550 nm has been demonstrated. The seed laser is a self-starting Er-doped fiber oscillator based on a Figure-9 configuration, generating pulses with a duration of 48 ps and a repetition rate of 15 MHz. To reduce spectral broadening during subsequent amplification, the pulse spectrum is reshaped into a near-Gaussian profile using a narrowband uniform fiber Bragg grating (FBG).

34.3 W, 172 µJ, 1342 nm picosecond master oscillator power amplifier.

A high-power, high-energy 1342 nm picosecond Nd:YVO master oscillator power amplifier (MOPA) laser system was demonstrated, comprising a SESAM mode-locked oscillator, a regenerative amplifier, and four main amplification stages consisting of two double-pass amplifiers and two single-pass amplifiers. Low-doping Nd:YVO crystals with undoped end caps, combined with 880 nm laser diode in-band pumping technique, were used to mitigate thermal effects. A pulse energy as high as 710 µJ at 10 kHz was obtained from the regenerative amplifier.

Ultrabroadband 12-fs mode-locked Yb:CALGO laser oscillator.

Pulse compression in Yb-doped lasers remains constrained by two critical bottlenecks: the narrow fluorescence spectrum of gain crystals and the inherently weak intracavity nonlinear spectral broadening effects. Here, through spectral-domain optimization of output coupler transmittance curves and using Yb:CALGO crystal as the gain medium, we have engineered enhanced output spectral bandwidth, enabling a 3.5-fold expansion in spectral bandwidth (Δλ = 323 nm at -10 dB) compared to the fluorescence spectrum.

Catechin suppresses HNSC via STXBP1 dependent inhibition of macrophage infiltration and CD47 mediated immune evasion.

The treatment of head and neck squamous cell carcinoma (HNSC) faces significant challenges, primarily due to the lack of reliable biomarkers and effective therapeutic drugs. This study reveals the crucial mechanistic role of STXBP1 in the HNSC tumor microenvironment: STXBP1 promotes tumor immune escape through dual pathways, not only enhancing the infiltration of M2-type macrophages but also activating the 'don't eat me' signaling pathway through upregulation of CD47. Clinical data analysis demonstrates that STXBP1 expression levels significantly correlate with HNSC patient prognosis, suggesting its potential as a diagnostic marker and prognostic indicator.

Halogen-Tuned BiOX (X = Cl, Br, I) Layered Crystals with Superior Broadband Nonlinear Saturable Absorption for Pulsed Laser Modulation.

Nonlinear optical (NLO) materials play indispensable roles in various fields, such as information, energy, and biology. However, the ideal NLO materials necessitate a balance between the band gap and the nonlinear coefficient, which severely restricts the further development of nonlinear optics. BiOX (X═Cl, Br, and I) crystals, with their layered structure, combine the advantages of nontoxicity, a tunable band gap, and remarkable optoelectronic properties, rendering them highly promising NLO materials.

High power narrow bandwidth picosecond PPLN-OPO.

A high power, narrow bandwidth, synchronously pumped PPLN optical parametric oscillator is demonstrated. By using a reflective volume bragg grating (RVBG), the signal laser wavelength is locked at 1908.1 nm while the bandwidth is compressed to 0.

Voltage tracking and regulation of vehicle PEMFC system under low load condition based on fuzzy LQG hybrid strategy.

In automotive fuel cell systems, high-voltage operation accelerates carbon support and platinum catalyst degradation, significantly compromising system durability. This study develops a dynamic system model with active cathode recirculation to capture the transient response of voltage, and proposes a hybrid control scheme that combines a proportional compensator with a fuzzy LQG controller to effectively enhance voltage regulation and disturbance tracking capabilities. Extensive simulation and hardware-in-the-loop (HiL) confirm the precision and rapid response of the developed controller.

Decentralized identifiers based IoT data trusted collection.

The data collection processes of IoT devices face significant security challenges, including access authorization, secure transmission, and secure storage. These challenges are particularly critical in sectors such as smart healthcare, smart homes, and smart cities, where users often lack direct ownership or control over IoT devices. Various solutions have been proposed to address these issues, leveraging technologies such as Certificate Authorities (CAs) and blockchain.

Quad-wavelength synchronously mode-locked bulk laser based on heterogeneous composite crystal with Fabry-Perot resonant structure.

Wave mixing (WM) techniques are crucial for applications such as supercontinuum generation, frequency conversion, and high-dimensional quantum encoding. However, their efficiency is often limited by complex phase-matching requirements, and current insights into phase-matching mechanisms for high-order WM remain limited. To address this, compact optical path configurations with high-peak-power, synchronous, multicolor ultrafast laser sources are needed to enhance high-order wave-mixing efficiency.

High-efficiency 2.3 µm Tm:YLF laser based on 0.79 µm and 1.05 µm dual-wavelength pumping scheme.

A high-efficiency Tm:YLF laser at 2.3 µm is demonstrated based on a dual-wavelength pumping scheme with 790 nm LD and a tunable Yb:CALGO laser at around 1.05 µm.

A novel energy efficient QoS secure routing algorithm for WSNs.

Quality of Service (QoS) routing protocol is a hot topic in the research field of wireless sensor networks (WSNs). However, the task of identifying an optimal path that simultaneously meets multiple QoS constraints is acknowledged as an NP-hard problem, with its complexity intensifying in proportion to the network's nodal count. Therefore, a novel heuristic multi-objective trust routing method, the Levy Chaos Adaptive Snake Optimization-based Multi-Trust Routing Method (LCASO-MTRM), is proposed, aiming to enhance link bandwidth while simultaneously reducing latency, packet loss, and energy consumption.

4.1 W continuous-wave and broadly wavelength tunable Tm-doped laser in 2.1-2.4 µm spectral region based on vibronic and electronic transitions.

Efficient diode-pumped continuous-wave (CW) and wavelength tunable Tm:YAP lasers based on the vibronic and electronic transitions are investigated. A total maximum output power of 4.1 W is achieved with multi-wavelength output around 2162 nm and 2274 nm, corresponding to a slope efficiency of 29.

All-solid-state ultrafast 2 µm laser with 1.83 W output power.

In this paper, a high-power all-solid-state ultrafast 2 µm mode-locked laser is investigated. The particularity of this laser is the simultaneous utilization of two Tm:YAP crystals in the same resonant cavity, independently pumped by two laser diodes. Using a 20% output coupler, pulses with output power as high as 1.

Sub-50-fs Kerr-lens mode-locked Yb-doped fluoride laser with 44% optical efficiency.

Yb-doped fluoride has been demonstrated to be potential crystals for application in efficient ultrafast lasers. However, the trade-off between the shorter pulses with higher efficiencies is a challenge. In this work, using , : crystal, we report on a sub-50-fs Kerr-lens mode-locked oscillator with an optical efficiency up to 44%.

Sub-100-fs Kerr-lens mode-locked Yb:LuO laser with more than 60% optical efficiency.

Yb-doped sesquioxides represent one of the most excellent laser crystals applying for high-power ultrafast lasers owing to their very high thermal conductivities and broadband emission spectra. Pumped by a high-brightness Yb-fiber laser at 976 nm, the Yb:LuO laser delivers a maximum output power that amounts to 3.55 W in the continuous-wave regime with an optical efficiency of 75%.

67 mJ, 137 ns narrow bandwidth 355 nm UV laser.

A high-efficiency, high-energy, narrow bandwidth, hundred-nanosecond pulse width 355 nm ultraviolet (UV) laser was realized. A high-energy single-frequency 1064 nm fundamental laser was demonstrated firstly with multistage end-pumped preamplifiers and side-pumped main amplifiers. The corresponding pulse energy, repetition rate, pulse duration, bandwidth, and beam quality factor M were determined to be 221 mJ, 100 Hz, 156 ns, 2.

Computed tomography in measuring electrode insertion angle and depth for cricopharyngeal muscle electromyography.

Background: Electromyography of the cricopharyngeal muscle (CP-EMG) is one of many assessment tools for dysphagia. The key to performing EMG and BTX injections is to precisely locate the cricopharyngeal muscle with an electrode. One of the main difficulties of electrode insertion is the fact that the CP muscle is located deep within the neck.

Cascade MIR Ho:YLF laser at 2.1 µm and 2.9 µm.

Cascade transitions of Ho:I→I and I→I provide a platform for a dual-wavelength mid-infrared (MIR) laser. In this paper, a continuous wave cascade MIR Ho:YLF laser operating at 2.1 and 2.

Self-Q-switched Er:LuO laser at 2.74 µm.

A diode-pumped self-Q-switched 2.74 µm Er:LuO crystal solid-state laser has been experimentally and theoretically studied. Without any additional modulation elements, stable self-Q-switched pulses with a pulse width of 145.

Passively Q-switched single crystal fiber pulsed laser at 1.05 µm with TCT as the saturable absorber.

In this paper, TiCT MXene prepared by LiF/HCl etching method was spin-coated on glass substrate and sapphire substrate as the saturable absorber (SA), and the MXene SA is combined with Yb: LuAG single crystal fiber (SCF) for the first time to achieve a 1.05 µm passively Q-switched pulsed laser output with the average power, pulse width, and repetition frequency of 1.989 W, 149.

Ferroelectric Domain Reversal Dynamics in LiNbO Optical Superlattice Investigated with a Real-Time Monitoring System.

The optical superlattice structure derived from a periodic poling process endows ferroelectric crystals with tunable optical property regulation, which has become one of the most efficient strategies for fabricating high-efficiency optical devices. Achieving a precise superlattice structure has been the main barrier for preparation of specific optical applications due to the unclear dynamics of domain structure regulation. Herein, a real-time monitoring system for the in situ observation of periodic poling of lithium niobate is established to investigate ferroelectric domain reversal dynamics.