Passively Q-Switched KTA Cascaded Raman Laser with 234 and 671 cm−1 Shifts

A compact KTA cascaded Raman system driven by a passively Q-switched Nd:YAG/Cr4+:YAG laser at 1064 nm was demonstrated for the first time. The output spectra with different cavity lengths were measured. Two strong lines with similar intensity were achieved with a 9 cm length cavity. One is the first-Stokes at 1146.8 nm with a Raman shift of 671 cm−1, and the other is the Stokes at 1178.2 nm with mixed Raman shifts of 234 cm−1 and 671 cm−1. At the shorter cavity length of 5 cm, the output Stokes lines with high intensity were still at 1146.8 nm and 1178.2 nm, but the intensity of 1178.2 nm was higher than that of 1146.8 nm. The maximum average output power of 540 mW was obtained at the incident pump power of 10.5 W with the pulse repetition frequency of 14.5 kHz and the pulse width around 1.1 ns. This compact passively Q-switched KTA cascaded Raman laser can yield multi-Stokes waves, which enrich laser output spectra and hold potential applications for remote sensing and terahertz generation.

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Diode-Pumped Eye-Safe Intracavity Raman Laser with Ceramic Nd:YAG Gain Medium and BaWO4 Raman Crystal

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.531.181 ◽

2012 ◽

Vol 531 ◽

pp. 181-184

Author(s):

Hui Hua Xu ◽

Xing Yu Zhang ◽

Qing Pu Wang ◽

Xiao Han Chen ◽

Cong Wang ◽

...

Keyword(s):

Pump Power ◽

Output Power ◽

Pulse Repetition Frequency ◽

Raman Laser ◽

Gain Medium ◽

Repetition Frequency ◽

Pulse Repetition ◽

Average Output ◽

Diode Pumped ◽

First Time

A diode-pumped actively Q-switched eye-safe intracavity Raman laser with ceramic Nd:YAG gain medium and BaWO4 Raman crystal is demonstrated for the first time. The highest average output power of 0.76 W is obtained at a pulse repetition frequency of 30 kHz and a pump power of 11.3 W. The corresponding conversion efficiency from the diode pump power to Raman output power is 6.7%. The highest pulse energy of 38.1 µJ is obtained at a pulse repetition frequency of 15 kHz and a pump power of 7.8 W, and the corresponding peak power is 4.9 kW.

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Diode-Pumped Actively Q-Switched Nd:YVO4/RTP Intracavity Raman Laser at 1.49 µm

Crystals ◽

10.3390/cryst9030168 ◽

2019 ◽

Vol 9 (3) ◽

pp. 168

Author(s):

Yue Jiao ◽

Zhaojun Liu ◽

Xingyu Zhang ◽

Feilong Gao ◽

Chenyang Jia ◽

...

Keyword(s):

Laser Radiation ◽

Pump Power ◽

Average Output Power ◽

Pulse Repetition Rate ◽

Frequency Conversion ◽

Raman Laser ◽

Laser Medium ◽

Average Output ◽

Diode Pumped ◽

First Time

For the first time, a diode-pumped actively Q-switched Nd:YVO4/RbTiOPO4 (RTP) intracavity Raman laser at 1.49 µm was demonstrated to the best of our knowledge. Experimentally, a dual-end diffusion-bonded YVO4–Nd:YVO4–YVO4 crystal was employed as the laser medium to generate 1.34 µm laser radiation, and an RTP crystal as the Raman medium to enable the frequency conversion, by which radiation at 1.49 µm was achieved successfully. With an incident pump power of 10.4 W, an average output power of 502 mW was obtained at a pulse repetition rate of 15 kHz, corresponding to a conversion efficiency of 4.8%.

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High-Power Large-Energy Raman Soliton Generations Within a Mode-Locked Yb-Doped Fiber Laser Based on High-Damage-Threshold CVD-MoS2 as Modulator

Nanomaterials ◽

10.3390/nano9091305 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1305

Author(s):

Pengfei Ma ◽

Wei Lin ◽

Huanian Zhang ◽

Shanhui Xu ◽

Zhongmin Yang

Keyword(s):

Fiber Laser ◽

High Power ◽

Damage Threshold ◽

Single Pulse ◽

Large Energy ◽

Two Dimensional ◽

Average Output ◽

Two Dimensional Materials ◽

Maximum Average Output Power ◽

First Time

In our work, based on a high-damage-threshold MoS2 saturable absorber (SA), high-power intra-cavity Raman solitons within a passively mode-locked Yb-doped fiber laser were demonstrated successfully for the first time. The damage threshold of the MoS2 SA was as high as ~0.48 J/cm2. By adjusting the polarization states, stable single- or dual-pulse Raman soliton operations were obtained. The maximum average output power for single-pulse and dual-pulse Raman soliton operations was 80.11 and 89.33 mW, respectively. Our experiment results show significant enhancement in comparison with previous works, which provides fundamental guidance for future designs of high-power, large-energy, intra-cavity Raman soliton generations based on two-dimensional materials as SAs.

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Passively Q-switched Yb-doped all-fiber laser based on Ag nanoplates as saturable absorber

Nanophotonics ◽

10.1515/nanoph-2020-0015 ◽

2020 ◽

Vol 9 (12) ◽

pp. 3873-3880

Author(s):

Bo Fu ◽

Pan Wang ◽

Yan Li ◽

Marcello Condorelli ◽

Enza Fazio ◽

...

Keyword(s):

Pump Power ◽

Fiber Laser ◽

Saturable Absorber ◽

Modulation Depth ◽

Single Pulse ◽

Average Output ◽

Saturable Absorbers ◽

Maximum Average Output Power ◽

Easy Integration ◽

First Time

AbstractWe report on a Q-switched Yb-doped all-fiber laser based on a solution-processed Ag nanoplates saturable absorber. Optical deposition procedure is implemented to transfer the Ag nanoplates onto the fiber core area through the thermal effect. The saturable absorber is sandwiched between two fiber connectors, providing simplicity, flexibility, and easy integration into the laser oscillator. The modulation depth and saturation incident fluence are measured to be ~5.8% and ~106.36 μJ/cm2 at 1-μm region, respectively. Self-started stable Q-switched operation is achieved for a threshold pump power of 180 mW. The repetition rates of the pulse trains range from 66.6 to 184.8 kHz when the pump power scales from 210 to 600 mW. The maximum average output power is 10.77 mW, corresponding to the single-pulse energy of 58.3 nJ and minimum pulse duration of ~1.01 μs. To the best of our knowledge, it is the first time that the Ag nanoplates saturable absorbers are utilized in the 1-μm Yb-doped Q-switched fiber laser.

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Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

10.26434/chemrxiv.5813979.v1 ◽

2018 ◽

Author(s):

Nicolò Bontempi ◽

Irene Vassalini ◽

Stefano Danesi ◽

Matteo Ferroni ◽

Paolo Colombi ◽

...

Keyword(s):

Critical Role ◽

Raman Laser ◽

Core Shell ◽

Thermal Coupling ◽

Melting Points ◽

Experimental Proof ◽

Weakly Coupled ◽

Light Management ◽

Laser Sources ◽

First Time

<p>Here we investigate for the first time the opto-thermal behavior of SiO<sub>2</sub>/Si core/shell microbeads (Si-rex) irradiated with three common Raman laser sources (lambda=532, 633, 785 nm) under real working conditions. We obtained an experimental proof of the critical role played by bead size and aggregation in heat and light management, demonstrating that in the case of strong opto-thermal coupling the temperature can exceed that of the melting points of both core and shell components. In addition, we also show that weakly coupled beads can be utilized as stable substrates for plasmon-free SERS experiments.</p>

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Preparation and Characterization of Chitosan-Casein Phosphopeptides Biocomposite Coatings on the Medical Titanium Alloy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.480-481.1065 ◽

2011 ◽

Vol 480-481 ◽

pp. 1065-1069

Author(s):

Bin Liu ◽

Lin Wang ◽

Yin Zhong Bu ◽

Sheng Rong Yang ◽

Jin Qing Wang

Keyword(s):

Photoelectron Spectroscopy ◽

Attenuated Total Reflectance ◽

Ti Alloy ◽

Force Microscopy ◽

Implant Materials ◽

Atomic Force ◽

Casein Phosphopeptides ◽

Potential Applications ◽

First Time

Titanium (Ti) and its alloys have been applied in orthopedics as one of the most popular biomedical metallic implant materials. In this work, to enhance the bioactivity, the surface of Ti alloy pre-modified by silane coupling agent and glutaraldehyde was covalently grafted with chitosan (CS) via biochemical multistep self-assembled method. Then, for the first time, the achieved surface was further immobilized with casein phosphopeptides (CPP), which are one group of bioactive peptides released from caseins in the digestive tract and can facilitate the calcium adsorption and usage, to form CS-CPP biocomposite coatings. The structure and composition of the fabricated coatings were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscopy (AFM). As the experimental results indicated, multi-step assembly was successfully performed, and the CS and CPP were assembled onto the Ti alloy surface orderly. It is anticipated that the Ti alloys modified by CS-CPP biocomposite coatings will find potential applications as implant materials in biomedical fields.

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Fabrication and Characterization of Lignin/Dendrimer Electrospun Blended Fiber Mats

Molecules ◽

10.3390/molecules26030518 ◽

2021 ◽

Vol 26 (3) ◽

pp. 518

Author(s):

Somaye Akbari ◽

Addie Bahi ◽

Ali Farahani ◽

Abbas S. Milani ◽

Frank Ko

Keyword(s):

Thermal Characteristics ◽

Dendritic Polymers ◽

Amino Groups ◽

Fiber Mats ◽

Potential Applications ◽

Solution Electrospinning ◽

Nanofiber Mats ◽

Softwood Kraft Lignin ◽

First Time

Blending lignin as the second most abundant polymer in Nature with nanostructured compounds such as dendritic polymers can not only add value to lignin, but also increase its application in various fields. In this study, softwood Kraft lignin/polyamidoamine dendritic polymer (PAMAM) blends were fabricated by the solution electrospinning to produce bead-free nanofiber mats for the first time. The mats were characterized through scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, zeta potential, and thermogravimetry analyses. The chemical intermolecular interactions between the lignin functional groups and abundant amino groups in the PAMAM were verified by FTIR and viscosity measurements. These interactions proved to enhance the mechanical and thermal characteristics of the lignin/PAMAM mats, suggesting their potential applications e.g. in membranes, filtration, controlled release drug delivery, among others.

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Continuous-Wave and Passively Q-Switched Er:Y2O3 Ceramic Laser at 2.7 μm

International Journal of Optics ◽

10.1155/2018/3153614 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

Zhipeng Qin ◽

Guoqiang Xie ◽

Jian Zhang ◽

Jingui Ma ◽

Peng Yuan ◽

...

Keyword(s):

Output Power ◽

Continuous Wave ◽

Maximum Output Power ◽

Maximum Output ◽

Average Output ◽

Semiconductor Saturable Absorber ◽

Infrared Spectral ◽

Maximum Average Output Power ◽

Ceramic Laser ◽

Stable Passive

We report on a continuous-wave (CW) and passively Q-switched Er:Y2O3 ceramic laser in mid-infrared spectral region. In the CW regime, a maximum output power of 2.07 W is achieved at 2717.3 nm with a slope efficiency of 13.5%. Stable passive Q-switching of the Er:Y2O3 ceramic laser is demonstrated based on semiconductor saturable absorber mirror. Under an absorbed pump power of 12.4 W, a maximum average output power of 223 mW is generated with a pulse energy of 1.7 μJ and a pulse width of 350 ns at 2709.3 nm.

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Topotactic route to synthesis of novel hydroxylated phases: I. Trioctahedral Micas

Clay Minerals ◽

10.1180/claymin.1986.021.2.02 ◽

1986 ◽

Vol 21 (2) ◽

pp. 125-131 ◽

Cited By ~ 6

Author(s):

S. Komarneni ◽

R. Roy

Keyword(s):

Ion Exchange ◽

Alkaline Earth ◽

Water Molecules ◽

Hydration Energy ◽

Hydrothermal Conditions ◽

Potential Applications ◽

Clay Layers ◽

First Time ◽

Hydrolysis Of ◽

Alkaline Earth Cations

AbstractK-depleted phlogopite mica was used as a topotactic precursor and treated with alkali (Li+, K+, , Rb+, Cs+), alkaline-earth (Mg2+, Ca2+, Sr2+, Ba2+) and trivalent (Al3+) cations under hydrothermal conditions of 200°C and 30 MPa pressure. K-, NH4-, Rb- and Cs-aluminosilicate micas were synthesised at 200°C in one day. The synthesis of Cs-aluminosilicate mica, with potential applications in the management of nuclear wastes, has been achieved for the first time by this approach. Ion exchange by Li+, Na+ and alkaline-earth cations under hydrothermal conditions did not produce anhydrous mica phases but resulted in hydrous phases with one or two layers of water molecules between the clay layers. The formation of hydrous phases may be attributed to the high hydration energy of the above cations compared to K+, , RB+ and Cs+. Ion exchange with Al3+ produced a chlorite-like phase because of the hydrolysis of Al3+ under these hydrothermal conditions. These studies are of relevance in the immobilization of wastes where hazardous ions can be fixed in highly stable insoluble phases like mica or chlorite.

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High Piezoelectric Conversion Properties of Axial InGaN/GaN Nanowires

10.20944/preprints201804.0383.v1 ◽

2018 ◽

Author(s):

Nikoletta Jegenyes ◽

Martina Morassi ◽

Pascal Chrétien ◽

Laurent Travers ◽

Lu Lu ◽

...

Keyword(s):

State Of The Art ◽

Electrical Energy ◽

Piezoelectric Response ◽

Average Output ◽

Gan Nanowires ◽

Piezoelectric Energy ◽

Atomic Force ◽

Maximum Value ◽

Promising Perspective ◽

First Time

We demonstrate for the first time efficient mechanical to electrical energy conversion using InGaN/GaN nanowires (NWs). Using an atomic force microscope equipped with a modified Resiscope module, we analyse the piezoelectric energy generation of GaN NWs and demonstrate an important enhancement when integrating in their volume a thick In-rich InGaN insertion. The piezoelectric response of InGaN/GaN NWs can be tuned as a function of the InGaN insertion thickness and position in the NW volume. The energy harvesting is favoured by the presence of a PtSi/GaN Schottky diode which allows to efficiently collect the piezo-charges generated by InGaN/GaN NWs. Average output voltages up to 330 ± 70 mV and a maximum value of 470 mV per NW has been measured for nanostructures integrating 70 nm-thick InGaN insertion capped with a thin GaN top layer. This latter value establishes an increase of about 35% of the piezo-conversion capacity in comparison with binary p-doped GaN NWs. By considering these output signals, we estimate a maximum power density generated by one layer of dense InGaN/GaN-based NW of about 3.3 W/cm2. These results settle the new state-of-the-art for piezo-generation from GaN-based NWs and offer a promising perspective for extending the performances of the piezoelectric sources.

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