R Realisierung rauscharmer 441,6 nm He-Cd-Laser durch Modulation des Entladungsstromes / Realization of low Noise 441,6 nm He-Cd-Lasers by Modulation of the Discharge Current

1977 ◽  
Vol 32 (12) ◽  
pp. 1503-1505 ◽  
Author(s):  
Tai-chiung Hsieh ◽  
Wolfgang Knauer ◽  
Uwe Penning
Keyword(s):  
Output Power ◽  
Discharge Current ◽  
Laser Light ◽  
Maximum Output Power ◽  
Low Noise ◽  
Laser Output ◽  
Maximum Output ◽  
Strong Reduction ◽  
Simple Method

Abstract Realization of low Noise 441,6 nm He-Cd-Lasers by Modulation of the Discharge Current A simple method to stabilize the laser light of a 441,6 nm He-Cd-laser at maximum output power is presented. Experiments show that a strong reduction of the fluctuations in the laser output can be achieved by a modulation of the discharge current at specific frequencies in the 100 kHz-range. This also leads to an increase in output power by 10-25 per cent as compared to the unmodulated laser.

scholarly journals One-Step Preparation of Biochar Electrodes and Their Applications in Sediment Microbial Electrochemical Systems

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 508
Author(s):  
Kui You ◽  
Zihan Zhou ◽  
Chao Gao ◽  
Qiao Yang
Keyword(s):  
Output Power ◽  
Electrode Materials ◽  
Maximum Output Power ◽  
Composite Cathode ◽  
Maximum Output ◽  
Electrochemical Systems ◽  
Composite Cathodes ◽  
One Step ◽  
Microbial Electrochemical Systems ◽  
Hot Melt

Biochar is a kind of carbon-rich material formed by pyrolysis of biomass at high temperature in the absence or limitation of oxygen. It has abundant pore structure and a large surface area, which could be considered the beneficial characteristics for electrodes of microbial electrochemical systems. In this study, reed was used as the raw material of biochar and six biochar-based electrode materials were obtained by three methods, including one-step biochar cathodes (BC 800 and BC 700), biochar/polyethylene composite cathodes (BP 5:5 and BP 6:4), and biochar/polyaniline/hot-melt adhesive composite cathode (BPP 5:1:4 and BPP 4:1:5). The basic physical properties and electrochemical properties of the self-made biochar electrode materials were characterized. Selected biochar-based electrode materials were used as the cathode of sediment microbial electrochemical reactors. The reactor with pure biochar electrode (BC 800) achieves a maximum output power density of 9.15 ± 0.02 mW/m2, which increases the output power by nearly 80% compared with carbon felt. When using a biochar/polyaniline/hot-melt adhesive (BPP 5:1:4) composite cathode, the output power was increased by 2.33 times. Under the premise of ensuring the molding of the material, the higher the content of biochar, the better the electrochemical performance of the electrodes. The treatment of reed powder before pyrolysis is an important factor for the molding of biochar. The one-step molding biochar cathode had satisfactory performance in sediment microbial electrochemical systems. By exploring the biochar-based electrode, waste biomass could be reused, which is beneficial for the environment.

scholarly journals Study of the Properties of a Hybrid Piezoelectric and Electromagnetic Energy Harvester for a Civil Engineering Low-Frequency Sloshing Environment

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 391
Author(s):  
Nan Wu ◽  
Yuncheng He ◽  
Jiyang Fu ◽  
Peng Liao
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Civil Engineering ◽  
Maximum Output Power ◽  
Low Frequency ◽  
Electromagnetic Energy ◽  
Maximum Output ◽  
Piezoelectric Film ◽  
Hybrid Energy ◽  
Level Height

In this paper a novel hybrid piezoelectric and electromagnetic energy harvester for civil engineering low-frequency sloshing environment is reported. The architecture, fabrication and characterization of the harvester are discussed. The hybrid energy harvester is composed of a permanent magnet, copper coil, and PVDF(polyvinylidene difluoride) piezoelectric film, and the upper U-tube device containing a cylindrical fluid barrier is connected to the foundation support plate by a hinge and spring. The two primary means of energy collection were through the vortex street, which alternately impacted the PVDF piezoelectric film through fluid shedding, and the electromotive force (EMF) induced by changes in the magnetic field position in the conducting coil. Experimentally, the maximum output power of the piezoelectric transformer of the hybrid energy harvester was 2.47 μW (circuit load 270 kΩ; liquid level height 80 mm); and the maximum output power of the electromagnetic generator was 2.72 μW (circuit load 470 kΩ; liquid level height 60 mm). The low-frequency sloshing energy collected by this energy harvester can drive microsensors for civil engineering monitoring.

LD-pumped high-power continuous-wave Pr3+:YLF deep red lasers at 718.5 and 720.8 nm

Laser Physics ◽  
2021 ◽  
Vol 32 (2) ◽  
pp. 025801
Author(s):  
Xiangrui Liu ◽  
Zhuang Li ◽  
Chengkun Shi ◽  
Bo Xiao ◽  
Run Fang ◽  
...  
Keyword(s):  
Output Power ◽  
High Power ◽  
Slope Efficiency ◽  
Laser Emission ◽  
Continuous Wave ◽  
Optical Glass ◽  
Maximum Output Power ◽  
Glass Plate ◽  
Maximum Output ◽  
First Time

Abstract We demonstrated 22 W LD-pumped high-power continuous-wave (CW) deep red laser operations at 718.5 and 720.8 nm based on an a-cut Pr3+:YLF crystal. The output power of both polarized directions reached the watt-level without output power saturation. A single wavelength laser operated at 720.8 nm in the π-polarized direction was achieved, with a high output power of 4.5 W and high slope efficiency of approximately 41.5%. To the best of our knowledge, under LD-pumped conditions, the laser output power and slope efficiency are the highest at 721 nm. By using a compact optical glass plate as an intracavity etalon, we suppressed the π-polarized 720.8 nm laser emission. And σ-polarized single-wavelength laser emission at 718.5 nm was achieved, with a maximum output power of 1.45 W and a slope efficiency of approximately 17.8%. This is the first time that we have achieved the σ-polarized laser emission at 718.5 nm generated by Pr3+:YLF lasers.

Design and Analysis of a High Power Density, Low Temperature Waste Heat Recovery System Using an Oil-Free Turboalternator

2010 ◽  
Author(s):  
James F. Walton ◽  
Andrew Hunsberger ◽  
Hooshang Heshmat
Keyword(s):  
Output Power ◽  
Waste Heat ◽  
Maximum Output Power ◽  
Output Power Level ◽  
Working Fluid ◽  
Prototype System ◽  
Low Grade ◽  
Maximum Output ◽  
Test Results ◽  
Study Results

In this paper the authors will present the design and preliminary test results for a distributed electric generating system that uses renewable energy source for economical load-following and peak-shaving capability in an oil-free, high-speed micro-turboalternator system using compliant foil bearings and a permanent magnet alternator. Test results achieved with the prototype system operating to full speed and under power generating mode will be presented. A comparison between predicted and measured electrical output will also be presented up to a power generating level of 25 kWe at approximately 55,000 rpm. The excellent correlation between design and test provides the basis for scale up to larger power levels. Based upon the turboalternator test results a thermodynamic cycle analysis of a system using low grade waste heat water at approximately 100 C will be reviewed. The tradeoff study results for a series of environmentally friendly refrigerant working fluids will also be presented including sensitivity to vaporization and condensing temperatures. Based on the cycle and pinch point analyses predicted maximum output power was determined. Finally a preliminary turbine design for the selected R134a working fluid was completed. The results of this study show that a net output power level of greater than 40 kW is possible for approximately 240 l/m flow of water at 100C is possible.

Modelling of Mechanical Nonlinearity in an Electromagnetic Vibration Energy Harvester Using a Forced Duffing Equation

2012 ◽  
Author(s):  
S. D. Moss ◽  
L. A. Vandewater ◽  
S. C. Galea
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Duffing Oscillator ◽  
Maximum Output Power ◽  
Vibration Energy ◽  
Maximum Output ◽  
Vibration Energy Harvesting ◽  
Vibration Energy Harvester ◽  
Homotopy Analysis ◽  
Wire Coil

This work reports on the modelling and experimental validation of a bi-axial vibration energy harvesting approach that uses a permanent-magnet/ball-bearing arrangement and a wire-coil transducer. The harvester’s behaviour is modelled using a forced Duffing oscillator, and the primary first order steady state resonant solutions are found using the homotopy analysis method (or HAM). Solutions found are shown to compare well with measured bearing displacements and harvested output power, and are used to predict the wideband frequency response of this type of vibration energy harvester. A prototype harvesting arrangement produced a maximum output power of 12.9 mW from a 12 Hz, 500 milli-g (or 4.9 m/s2) rms excitation.

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

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
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.

scholarly journals Design and Implementation of Charge Pump Phase-Locked Loop Frequency Source Based on GaAs pHEMT Process

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 504
Author(s):  
Ranran Zhao ◽  
Yuming Zhang ◽  
Hongliang Lv ◽  
Yue Wu
Keyword(s):  
Maximum Output Power ◽  
Charge Pump ◽  
Phase Locked Loop ◽  
Low Noise ◽  
Signal Frequency ◽  
Maximum Output ◽  
Voltage Controlled Oscillator ◽  
Chip Area ◽  
Frequency Source ◽  
A Charge

This paper realized a charge pump phase locked loop (CPPLL) frequency source circuit based on 0.15 μm Win GaAs pHEMT process. In this paper, an improved fully differential edge-triggered frequency discriminator (PFD) and an improved differential structure charge pump (CP) are proposed respectively. In addition, a low noise voltage-controlled oscillator (VCO) and a static 64:1 frequency divider is realized. Finally, the phase locked loop (PLL) is realized by cascading each module. Measurement results show that the output signal frequency of the proposed CPPLL is 3.584 GHz–4.021 GHz, the phase noise at the frequency offset of 1 MHz is −117.82 dBc/Hz, and the maximum output power is 4.34 dBm. The chip area is 2701 μm × 3381 μm, and the power consumption is 181 mw.

Sign in / Sign up

Export Citation Format

Share Document