scholarly journals Passively Q-Switched Yb:CALGO Laser Based on Mo:BiVO4 Absorber

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2364
Author(s):  
Lina Zhao ◽  
Ye Yuan ◽  
Luyang Tong ◽  
Wenyu Zhang ◽  
Zhongshuai Zhang ◽  
...  

A stable, passively Q-switched Yb:CaGdAlO4 laser based on Mo:BiVO4 saturable absorber was demonstrated. Close observations of the structure and morphology of the nanoparticles by using transmission electron microscope, Raman spectrum and linear absorption were measured. The nonlinear transmission of Mo:BiVO4 was characterized by a 30 ps laser with a central wavelength of 1064 nm and a repetition rate of 10 Hz. The experimental maximum output power of the pulsed laser was 510 mW with a repetition rate of 87 kHz and pulse width of 3.18 μs, corresponding to a peak power of 1.84 W and a single pulse energy of 5.8 μJ. The experimental results indicate that Mo:BiVO4-SA is a great candidate for passively Q-switched lasers in the near infrared region.

2016 ◽  
Vol 94 (4) ◽  
pp. 389-392 ◽  
Author(s):  
Shang Gao

A diode-end-pumped, passively Q-switched, Nd:YAG laser with a monolayer graphene as saturable absober simultaneously emitting at 1319 and 1338 nm was demonstrated for the first time. The maximum output power, the minimum pulse duration and the highest repetition rate were 586 mW, 317 ns, and 102 kHz, respectively. The corresponding peak power was about 18.1 W.


2021 ◽  
Vol 2075 (1) ◽  
pp. 012013
Author(s):  
N Ahmed ◽  
S Omar ◽  
NF Zulkipli ◽  
Z Jusoh ◽  
HA Rahman ◽  
...  

Abstract A passive mode-locked in an erbium-doped fiber laser with titanium dioxide (TiO2) film as a saturable absorber (SA) has been successfully demonstrated. The film is fabricated using a liquid phase exfoliation, which offers a simple and low-cost method. The self-starting mode-locked was created by inserting a 200-meter-long single-mode fiber into the laser cavity to balance the nonlinearity and dispersion of the cavity. The pulses operate stably at a central wavelength of 1560 nm. The pulse repetition rate was almost fixed at 988 kHz at a tuneable pump power from 145.83 mW to 187.04 mW. The repetition rate shows excellent stability with a signal-to-noise ratio (SNR) of 69 dB whilst the pulse width was virtually constant at 230 ns. The maximum output power was measured at 2.17 mW, eliciting maximum pulse energy of 2.19 nJ. This experiment demonstrates that stable mode-locked pulsed can be generated using TiO2-SA.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3460
Author(s):  
Jingcheng Shang ◽  
Yizhou Liu ◽  
Shengzhi Zhao ◽  
Yuefeng Zhao ◽  
Yuzhi Song ◽  
...  

We experimentally investigate the formation of various pulses from a thulium–holmium (Tm–Ho)-codoped nonlinear polarization rotation (NPR) mode-locking fiber oscillator. The ultrafast fiber oscillator can simultaneously operate in the noise-like and soliton mode-locking regimes with two different emission wavelengths located around 1947 and 2010 nm, which are believed to be induced from the laser transition of Tm3+ and Ho3+ ions respectively. When the noise-like pulse (NLP) and soliton pulse (SP) co-exist inside the laser oscillator, a maximum output power of 295 mW is achieved with a pulse repetition rate of 19.85-MHz, corresponding to a total single pulse energy of 14.86 nJ. By adjusting the wave plates, the fiber oscillator could also deliver the dual-NLPs or dual-SPs at dual wavelengths, or single NLP and single SP at one wavelength. The highest 61-order harmonic soliton pulse and 33.4-nJ-NLP are also realized respectively with proper design of the fiber cavity.


Author(s):  
Jiaxin Song ◽  
Hanshuo Wu ◽  
Jun Ye ◽  
Hanwei Zhang ◽  
Jiangming Xu ◽  
...  

In this paper, we experimentally investigated the extreme frequency shift in high-power Raman fiber laser (RFL). The RFL was developed by using a pair of fiber Bragg gratings with fixed and matched central wavelength (1120 nm) combined with a piece of 31-m-long polarization maintaining (PM) passive fiber adopted as Raman gain medium. The pump source was a homemade high-power, linearly polarized (LP) wavelength-tunable master oscillator power amplifier (MOPA) source with ${\sim}25~\text{nm}$ tunable working range (1055–1080 nm). High-power and high-efficiency RFL with extreme frequency shift between the pump and Stokes light was explored. It is found that frequency shift located within 10.6 THz and 15.2 THz can ensure efficient Raman lasing, where the conversion efficiency is more than 95% of the maximal value, 71.3%. In addition, a maximum output power of 147.1 W was obtained with an optical efficiency of 71.3%, which is the highest power ever reported in LP RFLs to the best of our knowledge.


Author(s):  
Jie Guo ◽  
Wei Wang ◽  
Hua Lin ◽  
Xiaoyan Liang

We report on a high-repetition-rate, high-power continuously pumped Nd:GdVO4 regenerative amplifier. Numerical simulations successfully pinpoint the optimum working point free of bifurcation instability with simultaneous efficient energy extraction. At a repetition rate of 100 kHz, a maximum output power of 23 W was obtained with a pulse duration of 27 ps, corresponding to a pulse energy of $230~\unicode[STIX]{x03BC}\text{J}$ . The system displayed an outstanding stability with a root mean square power noise as low as 0.3%. The geometry of the optical resonator and the pumping scheme enhanced output power in the $\text{TEM}_{00}$ mode with a single bulk crystal. Accordingly, nearly diffraction-limited beam quality was produced with $M^{2}\approx 1.2$ at full pump power.


MRS Advances ◽  
2016 ◽  
Vol 1 (30) ◽  
pp. 2181-2186 ◽  
Author(s):  
Luis M. Angelats-Silva ◽  
David Asmat-Campos ◽  
Henry León-León ◽  
Kevin A. Wilkinson ◽  
Daniel A. Sánchez-Vaca ◽  
...  

ABSTRACTWe report preparation and characterization of colloidal gold nanorods (AuNR) with plasmon absorbance over 950 nm and an aspect ratio of 7.2 by tuning silver nitrate concentration and the CTAB/BDAC ratio during growth. Samples were analyzed by scanning transmission electron microscopy, X-ray diffraction, UV-vis absorption spectroscopy and measurement of zeta potential. Addition of 170 μM silver nitrate to the CTAB-containing reaction mixture allowed preparation of AuNRs with a maximum absorbance peak at 941.8 nm and a yield around 96%. Optimization of the BDAC/CTAB ratio allowed for a further redshift of the absorbance maximum to 954.0 nm, but with poorer yields.


1959 ◽  
Vol 32 (2) ◽  
pp. 628-638
Author(s):  
G. A. Blokh ◽  
A. F. Mal'nev

Abstract The newest physical-chemical methods of research enlarge the scope of study of the vulcanization process. There is a possibility of studying the structure changes during vulcanization of rubber by the application of infrared spectroscopy. Infrared rays are selectively absorbed. Therefore the infrared absorption spectrum can be used as a characteristic property of a substance and could be used for analytical purposes. The large spectral range of the infrared rays indicates their importance for the study of the properties and structure of substances; this makes possible the determination of the moments of inertia of atomic nuclei and molecules, isotopic mass, arrangement and strength of atomic bonds in the molecule and the frequencies of their vibrations. By knowing the frequencies for pure substances, molecular analyses of complicated mixtures of various organic rubbers, accelerators and other substances could be performed. The study of linear absorption spectra is the basis of the spectrographic method in the infrared region. Since the frequencies of near infrared radiation correspond to the characteristic frequencies of the atoms in the molecules, this method could be used to obtain interesting information concerning the structure of organic molecules, the chemical structure of high molecular weight compounds, the determination of the presence of specific groups or atoms in the rubber molecule, the character of the bonds between these groups and the order of arrangement of the individual chain links. This is true because the position of the absorption bands, which are specific for a given group of atoms, is practically the same for the different combinations in which the group occurs. The complicated process of polymerization of diene and vinyl compounds and the structure of different types of rubbers can be investigated with the aid of infrared spectroscopy. For example, Table I lists the characteristic absorption frequencies in the infrared region for some important chemical combinations.


2009 ◽  
Vol 23 (22) ◽  
pp. 2647-2653 ◽  
Author(s):  
XIAO-NIU PENG ◽  
XIAN ZHANG ◽  
LIAO YU ◽  
LI ZHOU

Porous anodized aluminum oxide (AAO) template was combined with sol-gel method in this work for the fabrication of high-ordered NdVO4nanotube arrays. The diameter, length, and wall thickness of the nanotubes can be adjusted conveniently. The sample was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), absorption spectra, and photoluminescence spectra. The results show that these uniformly distributed, high-ordered, and parallel nanotubes have great light emission in both the visible region and near-infrared region due to their corresponding energy level transitions. With this method, future application of rare-earth hollow nanostructures will be widely extended.


2000 ◽  
Vol 623 ◽  
Author(s):  
R. Noshiro ◽  
K. Ueda ◽  
H. Hosono ◽  
H. Kawazoe

AbstractThin films of MgIn2O4 spinel, which is a recently discovered TCO material, were deposited on MgO (100) surface by PLD. The thin films were prepared under low oxygen partial pressure to enhance formation of oxygen vacancies, from which carrier electrons were generated. X-ray analyses and AFM observations suggest epitaxial growth of the grains with diameter of 100∼200nm. The grains showed strong orientations both along the normal of the thin film and in plane. Epitaxial growth of the spinel was also confirmed by high-resolution transmission electron microscopic observations. The lattice image of the interface region suggests formation of structural imperfections such as dislocations, grain boundaries and amorphous phase in significant fraction. Strong optical absorption due to electron carriers was detected in near infrared region. Very large Burnstein-Moss shift was observed in ultraviolet region, and the optical band gap was estimated to be 4.3eV. DC conductivity observed was 4.5×103Scm−1, which is the highest value reported for the material so far. Concentration and Hall mobility of carrier electrons were found to be 2.1×1021cm−3 and 14cm2V−1s−1, respectively.


Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2515-2522 ◽  
Author(s):  
Dan Zhang ◽  
Chenxi Zhang ◽  
Xiaohui Li ◽  
Abdul Qyyum

AbstractTwo-dimensional (2D) transition metal dichalcogenide materials have attracted much attention in recent years due to their excellent electro-optical properties. FeS2, the ideal composition of iron pyrite, is a 2D transition metal dichalcogenide which has been potentially used in the electronic, optical, and chemical fields. On the other hand, the narrow band gap of FeS2 (≈0.96 eV) makes it very suitable and promising for the ultrafast application in near-infrared regimes. However, the potential application of FeS2 in laser technology has not been explored till now. Ultrashort pulse lasers have great applications in industry and science because of its stability, ease of operation, and portability. Passively mode-locked fiber lasers using 2D materials (such as MoS2, CuS2, and WS2) as saturable absorber are intensively investigated. Here, layered FeS2 has been characterized systematically. It is successfully applied in ultrafast photonics and plays a key component in the passively mode-locked laser for the first time. The single pulse can be obtained with 1.7-ps pulse duration, 1.89-nm spectral width, and fundamental repetition of 6.4 MHz at 1563 nm central wavelength. Through controlling the pump power, the evolution of the pulse train can be observed, which can be transformed from single pulse to bound states. Also, the harmonic mode-locked fiber laser is observed with the pump power high enough.


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