- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Compression of femtosecond pulses in a wide wavelength range using a large-mode-area tapered fiber
摘要： We report the design of a tapered fiber that can be used for the compression of pulses at different central wavelengths. The proposed fiber is a three-layer W-type large-mode-area fiber, which has been tapered to transform the mode area from 1700 μm2 to 900 μm2. We determine the exact length of the maximum pulse compression and numerically demonstrate the compression of a 250 fs, 100 kW peak power input pulse to 15 fs, 850 kW at 1.55 μm wavelength and compression of 250 fs, 120 kW peak power input pulses to 28 fs, 700 kW and to 46 fs, 500 kW at 1.8 μm and 2 μm wavelengths, respectively. Such a fiber can find wide ranging applications, including in communication, spectroscopy and medicine.
关键词： ultrafast processes in fiber,large-mode-area fiber,high peak power femtosecond pulses,pulse shaping,tapered fiber,pulse compression
更新于2025-09-23 15:22:29
-
High-peak-power and narrow-linewidth Q-switched Ho:YAG laser in-band pumped at 1931 nm
摘要： We describe a high-peak-power, narrow-linewidth Q-switched Ho:YAG laser at 2097 nm wing-pumped by a high power and high brightness Tm:fiber source at 1931.5 nm. The laser was wavelength locked and spectrum narrowed utilizing a volume Bragg grating as the input coupler, resulting a linewidth (FWHM) of less than 0.1 nm. At 22.7 W of incident pump power, stable pulses of 5.5 mJ pulse energy and 17.5 ns of pulse duration have been generated at repetition frequency of 1 kHz, corresponding to peak power of 314.3 kW.
关键词： narrow-linewidth,Q-switched Ho:YAG laser,volume Bragg grating,1931.5 nm,high-peak-power
更新于2025-09-23 15:21:01
-
High peak power, high-repetition rate passively Q-switching of a holmium ceramic laser
摘要： We demonstrated a high peak power, high repetition rate Cr2+:ZnS passively Q-switched (PQS) Ho:YAG ceramic laser. Particularly, the influence of the initial transmission of the saturable absorber (SA) on the laser performance was investigated with two kinds of SAs. Finally, the laser generated average output power of 10.3 W and the stable 13.3 ns, 1.02 mJ pulses were achieved at a 10.1 kHz repetition rate. In addition, the highest peak power of 75.9 kW was obtained, to our best knowledge, which was also the highest peak power achieved in a ~2 μm PQS ceramic laser, corresponding to the intra-cavity peak power of 0.23 MW.
关键词： passively Q-switched (PQS),ceramic materials,high-peak power
更新于2025-09-23 15:19:57
-
Investigation on the Continuous Wave Mode and the ms Pulse Mode Fiber Laser Drilling Mechanisms of the Carbon Fiber Reinforced Composite
摘要： The near infrared (NIR) laser drilling of a carbon fiber reinforced polymer (CFRP) composite in the continuous wave (CW) mode and the ms pulse mode was investigated by an experiment and a numerical simulation. The relationships between the laser penetrating time, entrance hole diameter, surface heat affected zone (HAZ) width, and material ablation rate and the laser irradiation time and laser peak power densities were obtained from the experiment. For the same average power density of the laser output, 3.5 kW/cm2, it was found that the ms pulse laser mode, which had a higher peak power density, had a higher drilling efficiency. When drilling the same holes, the pulse laser mode, which had the highest peak power density of 49.8 kW/cm2, had the lowest drilling time of 0.23 s and had the smallest surface HAZ width of 0.54 mm. In addition, it was found that the laser penetrating time decreased sharply when the peak power density was higher than 23.4 kW/cm2. After analyzing the internal gas pressure by the numerical simulation, it was considered that a large internal gas pressure appeared, which resulted from polymer pyrolysis, causing a large amount of the mechanical erosion of the composite material to improve the drilling efficiency. Therefore, the ms pulse laser showed its potential and advantage in laser drilling the CFRP composite.
关键词： ms pulse,mechanical erosion,peak power density,surface HAZ,laser drilling
更新于2025-09-23 15:19:57
-
Doubly passively Q-switched Tm:YAP laser with MoS2 and WS2 saturable absorbers at 2 μm
摘要： By simultaneously inserting MoS2 and WS2 saturable absorbers (SAs) into laser resonator, a doubly passively Q-switched Tm:YAP laser at 2 μm was realized. Measurements of the average output power, the pulse width and the pulse repetition frequency (RF) have been undertaken. In comparison to singly Q-switched laser using MoS2 or WS2, the doubly Q-switched laser using both MoS2 and WS2 can generate more stable pulse trains with shorter pulse width and higher peak power. At the absorbed pump power of 6.04 W, the maximum peak power of 22.4 W and the shortest pulse width of 249.4 ns were obtained. While for singly Q-switched laser using MoS2 or WS2, they were 10.7 W, 528.4 ns and 14.4 W, 458.8 ns. The experimental results hit at a conclusion that the doubly passively Q-switched operation is an e?cient way to compress the pulse width, improve the peak power and enhance the stability of pulse trains at 2 μm waveband laser.
关键词： Pulse width,Peak power,Doubly passively Q-switch,Two-dimensional material
更新于2025-09-19 17:13:59
-
Doubly Q-switched Tm:YAP laser with g-C3N4 saturable absorber and AOM
摘要： Two-dimensional (2D) graphitic carbon nitride (g-C3N4) was fabricated as saturable absorber (SA) and the nonlinear optical absorption properties were measured. A laser-diode (LD) pumped doubly Q-switched Tm-doped yttrium-aluminium perovskite YAlO3 (Tm:YAP) laser at 2 μm with g-C3N4 and acousto-optic modulator (AOM) is presented for the ?rst time to the best of our knowledge. Under an absorbed pump power of 5.34 W, the minimum pulse width of 239 ns and the maximum peak power of 1146 W were obtained by the doubly Q-switched laser. In comparison with the singly Q-switched laser using g-C3N4 SA or AOM, the dual-loss-modulated Q-switched laser could generate shorter pulse width and higher peak power. The maximum pulse width compression ratio was 4.48 and the highest peak power enhancement factor was 241. The experimental results indicated that 2D g-C3N4 SA is potential in Q-switched laser at 2 μm and the doubly Q-switched technology is a useful way to compress the pulse width and improve the peak power.
关键词： Pulse width,Doubly Q-switch,g-C3N4,Peak power,2 μm waveband
更新于2025-09-19 17:13:59
-
[Laser Institute of America ICALEO? 2014: 33rd International Congress on Laser Materials Processing, Laser Microprocessing and Nanomanufacturing - San Diego, California, USA (October 19–23, 2014)] International Congress on Applications of Lasers & Electro-Optics - ITO patterning using advanced green and infrared pulsed fiber lasers
摘要： Laser patterning of Indium Tin Oxide (ITO) deposited on bulk substrates enables a chemical waste free, high throughput process that is widely used in flat panel and touch panel display devices. To attain economic viability and meet the need for narrow touch sensor borders with high quality ITO patterning, the width, uniformity, and throughput of the scribing lines are key quality parameters. In this talk we report on the advances in pulsed nanosecond fiber lasers at wavelengths of 532 and 1064-nm with optimized parameters for meeting theses critical requirements. Specifically, near diffraction-limited beam quality, high peak power capabilities, short pulses, and fast transient response are necessary to produce consistent scribed lines in the order of 10?m in width with smooth edges. The results of our study demonstrate the advantage of using the IR laser as a robust, cost-effective solution for scribing lines with a width in between 15-25?m. However, the ability to focus the beam of the green laser more tightly makes it the preferred candidate for meeting the 10?m width target.
关键词： 1064nm,PRF,532nm,nanosecond,ITO patterning,peak power,pulse duration,fiber lasers,beam quality
更新于2025-09-16 10:30:52
-
[Laser Institute of America ILSC? 2019: Proceedings of the International Laser Safety Conference - South Kissimmee, Florida, USA (March 18–21, 2019)] International Laser Safety Conference - Computer modelling to support laser safety analysis of pulse trains with varying peak power and pulse duration
摘要： Neither the international laser safety standard IEC 60825-1 Edition 3.0 nor the standard ANSI Z136.1-2014 provide specific rules on how to apply the pulse reduction factor C5 (resp. CP) to irregular pulse trains, featuring both varying peak power as well as varying pulse duration. Without specific guidance, the analysis has to be performed based on restrictive approaches, such as counting all pulses and giving them the same weight, even the ones with smaller peak power and lower energy. Preliminary work, presented at the ILSC 2017, focused on pulse trains with varying peak power. The present study provides guidance on how to analyze irregular pulse patterns - both in terms of peak power and pulse duration - in a less restrictive way.
关键词： peak power,IEC 60825-1,ANSI Z136.1,pulse duration,laser safety,pulse trains
更新于2025-09-16 10:30:52
-
Investigation of datasheet provided temperature coefficients of photovoltaic modules under various sky profiles at the field by applying a new validation procedure
摘要： In this study, datasheet provided temperature coefficients of commercially available photovoltaic modules were investigated by taking into account the actual performance parameters (output peak power, short-circuit current and open-circuit current) under different sky profiles (clear, partly cloudy and cloudy) at field by introducing a new validation procedure. This procedure is based on two cases. The first case covers irradiation and temperature whereas the second case covers only irradiation by neglecting the temperature coefficient parts in the actual performance parameters calculation. The actual performance parameters of mono crystalline silicon and cupper indium gallium selenide photovoltaic modules were measured under different sky profiles at field and calculated for considered cases. Measured and calculated results were compared by using the root mean square error and the relative mean error tools. It has been founded that temperature coefficients of commercially available photovoltaic modules could deviate from their datasheet provided values under cloudy sky profile at field. As a result of this, it has been concluded that users should take into account sky profiles at the site where photovoltaic modules are going to be deployed in order to calculate the actual performance parameters and the output energy accurately.
关键词： short-circuit current,output peak power,photovoltaic module,electrical output,open-circuit voltage,temperature coefficient
更新于2025-09-16 10:30:52
-
All-fiber sub-20a??ps ultra low repetition rate high peak power mode-locked fiber laser to generate supercontinuum
摘要： We report an ultra-low repetition rate self-started mode-locked fiber laser at 1.55 μm spectral region with a sub-20 ps pulse duration at repetition rate of less than 100 kHz leading to high energy and peak power pulses. A repetition rate of 13.8 kHz with the pulsewidth of 17 ps is then achieved and the issue of multiple pulses is mitigated in the linear cavity structure by proper selection of semiconductor saturable absorber and dispersion management in the cavity. A broad supercontinuum achieved using 7 m SM-ZBLAN fiber while pumping with mode-locked fiber laser with repetition rate, pulsewidth, pulse energy and peak power of 53 kHz, 12.5 ps, 16.6 μJ and 1.3 MW, respectively.
关键词： mode-locked fibre laser,ultra low repetition rate,high peak power pulsed laser,ZBLAN single mode fiber (SMF),supercontinuum
更新于2025-09-16 10:30:52