scholarly journals Environmentally stable black phosphorus saturable absorber for ultrafast laser

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2445-2449 ◽  
Author(s):  
Xinxin Jin ◽  
Guohua Hu ◽  
Meng Zhang ◽  
Tom Albrow-Owen ◽  
Zheng Zheng ◽  
...  

AbstractBlack phosphorus (BP) attracts huge interest in photonic and optoelectronic applications ranging from passive switch for ultrafast lasers to photodetectors. However, the instability of chemically unfunctionalized BP in ambient environment due to oxygen and moisture remains a critical barrier to its potential applications. Here, the parylene-C layer was used to protect inkjet-printed BP-saturable absorbers (BP-SA), and the efficacy of this passivation layer was demonstrated on the stable and continuous operation of inkjet-printed BP-SA in harsh environmental conditions. BP-SA was integrated in an erbium-doped ring laser cavity and immersed in water at ~60°C during operation for investigation. Mode-locked pulses at ~1567.3 nm with ~538 fs pulse width remained stable for >200 h. The standard deviation of spectral width, central wavelength, and pulse width were 0.0248 nm, 0.0387 nm, and 2.3 fs, respectively, in this period, underscoring the extreme stability of BP-SA against high temperature and humidity. This approach could enable the exploitation of BP-based devices for photonic applications when operating under adverse environmental conditions.

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2557-2567 ◽  
Author(s):  
Huanian Zhang ◽  
Pengfei Ma ◽  
Mingxiao Zhu ◽  
Wenfei Zhang ◽  
Guomei Wang ◽  
...  

AbstractAir-stable broadband saturable absorbers (SAs) exhibit a promising application potential, and their preparations are also full of challenges. Palladium selenide (PdSe2), as a novel two-dimensional (2D) layered material, exhibits competitive optical properties including wide tunable bandgap, unique pentagonal atomic structure, excellent air stability, and so on, which are significant in designing air-stable broadband SAs. In our work, theoretical calculation of the electronic band structures and bandgap characteristics of PdSe2 are studied first. Additionally, PdSe2 nanosheets are synthesized and used for designing broadband SAs. Based on the PdSe2 SA, ultrafast mode-locked operations in 1- and 1.5-μm spectral regions are generated successfully. For the mode-locked Er-doped operations, the central wavelength, pulse width, and pulse repetition rate are 1561.77 nm, 323.7 fs, and 20.37 MHz, respectively. Meanwhile, in all normal dispersion regions, mode-locked Yb-doped fiber laser with 767.7-ps pulse width and 15.6-mW maximum average output power is also generated successfully. Our results fully reveal the capacity of PdSe2 as a broadband SA and provide new opportunities for designing air-stable broadband ultra-fast photonic devices.


2019 ◽  
Vol 28 (03) ◽  
pp. 1950026 ◽  
Author(s):  
H. Ahmad ◽  
S. Soltani ◽  
K. Thambiratnam

In this study, short [Formula: see text]-switching laser pulses are generated by drop-casting two-dimensional Molybdenum Disulfide (MoS[Formula: see text] nanoparticles as saturable absorbers (SA) on a side polished optical fiber in a [Formula: see text]-band laser cavity. The proposed laser is capable of generating highly stable [Formula: see text]-switched laser pulses at the wavelength of 1559.42[Formula: see text]nm with a maximum repetition rate of 73.96[Formula: see text]kHz, and a minimum pulse width of 1.93[Formula: see text][Formula: see text]s. The relatively high signal-to-noise ratio of 58.7[Formula: see text]dB indicates a highly stable output. The proposed SA can be applied in a variety of fields due to its ease of manufacturing and cost-effectiveness as well as its robust and compact design.


Author(s):  
L. V. Tashmatova ◽  
О. V. Mantseva ◽  
N. V. Gorbacheva

The basic moments of a process of obtaining apple tetraploids as donors of diploid gametes for apple breeding with polyploidy using are demonstrated. In industrial terms, triploids are of the greatest importance. The manifested effect of heterosis leads to the improvement of many characteristics - higher resistance to diseases, pests and adverse environmental conditions, greater autogamy than in diploids, less pronounced periodicity of fruiting, larger fruits and a convenient crown for harvesting. Triploids are developed as a result of crosses 2n × 3n or 2n × 4n. Tetraploids are necessary for more successful apple breeding with polyploidy using. For industry they are not of great importance but they are of interest as donors of diploid non-reduced gametes and allow to make the selection process more directional. One of the methods of experimental polyploidy is the induction of polyploids using mutagenes. The germs were treated with colchicines at concentrations 0.1% - 0.4% during 24 and 48 hours. According to the morphology the obtained plants were divided into five groups. Colchicine concentrations 0.3% and 0.4% during 48 hours of the treatment had a disastrous impact on the development of germs. As a result of the cytological analysis, tetraploids and chimeras were revealed, which were obtained from the seeds from the open pollination of Orlik and Svezhest (treatment variants – 0,1% colchicines solution and 24 and 48 hours of exposition), as well as from the seeds obtained as a result of the Svezhest × Bolotovskoye crossing. Tetraploids had a normal growth but they differed in large leaves, while chimeras were of low size with normal leaves and internodes.


2021 ◽  
Vol 19 (8) ◽  
pp. 081405
Author(s):  
Mengyu Zhang ◽  
Hao Chen ◽  
Jinde Yin ◽  
Jintao Wang ◽  
Jinzhang Wang ◽  
...  

2015 ◽  
Vol 74 (8) ◽  
Author(s):  
A. A. Latiff ◽  
M. T. Ahmad ◽  
Z. Zakaria ◽  
H. Ahmad ◽  
S. W. Harun

An 1892.4 nm ultrafast passive Q-switched fiber laser is demonstrated by using Thulium-doped fiber (TDF) in conjunction with a multi-walled carbon nanotubes (MWCNTs) as a saturable absorber (SA). The MWCNTs film is sandwiched between two FC/PC fiber connectors and integrated into the laser cavity with 802 nm pump for Q-switching pulse generation. The pulse repetition rate can be tuned from 3.8 to 4.6 kHz while the corresponding pulse width reduces from 22.1 to 18.4 μs as the pump power is increased from 187.3 to 194.2 mW. A higher performance Q-switched Thulium-doped fiber laser (TDFL) is expected to be achieved with the optimization of the MWCNT-SA saturable absorber and laser cavity.


1975 ◽  
Vol 19 (3) ◽  
pp. 301-304
Author(s):  
Ann E. Martin

The present study was conducted to investigate the effects of environmental conditions on visual workload. The environmental variables used were temperature, studied at levels of 45°F., WBGT, and 95°F., WBGT; and noise, studied at 83 dBA intermittent noise and 93 dBA continuous noise. Workload was defined as the amount of attention demanded from an operator as measured by performance decrement on a secondary task while performing a primary and secondary task simultaneously. The secondary task was reading random numbers, and the primary task was reading word lists. Significant differences (p<.05) were found between the control condition and all experimental conditions. The low temperature and high temperature-continuous noise conditions were significantly different from the other conditions. Noise and temperature were found to significantly increase workload (p<05).


Sign in / Sign up

Export Citation Format

Share Document