wavelength tunable
Recently Published Documents





2022 ◽  
Vol 147 ◽  
pp. 107598
Hsin-Ju Peng ◽  
Zhen-Ying Li ◽  
Shwu-Yun Tsay ◽  
Yu-Feng Song ◽  
Han Zhang ◽  

Laser Physics ◽  
2021 ◽  
Vol 32 (1) ◽  
pp. 015103
Jing Li ◽  
Chuncan Wang ◽  
Peng Wang ◽  
Pengtao Liu ◽  
Junhao Lan ◽  

Abstract A method for obtaining picosecond pulse sources with continuously tunable central wavelengths is demonstrated numerically and experimentally. A dissipative soliton (DS) mode-locked erbium-doped fiber (EDF) laser based on the nonlinear polarization rotation provides the seed pulse with a flat-top spectral profile and a 55 nm spectral bandwidth. Then it is filtered by a wavelength-tunable super-Gaussian bandpass filter and amplified by two segments of EDFs with different doping concentrations. The output DS pulse from the EDF laser can be compressed from 5.532 ps to 0.291 ps by using a single-mode fiber (SMF-28e), while the pulse energy is about 1.6 nJ. Furthermore, the about 4 ps and 6.84 nJ pulses with continuously tunable central wavelengths ranging from 1535 to 1580 nm can be obtained by amplifying the spectrally filtered pulses. The tunable picosecond pulse source based on the extra-cavity filtering method is very useful for many practical applications because of its flexible wavelength control.

2021 ◽  
Kong Gao ◽  
Yizhou Liu ◽  
Wenchao Qiao ◽  
Yuzhi Song ◽  
Xian Zhao ◽  

2021 ◽  
Jiaqiang Lin ◽  
Tianhao Dong ◽  
Yimin zhang ◽  
Peijun Yao ◽  
Chun Gu ◽  

2021 ◽  
Vol 11 (1) ◽  
Ichiro Tatsuno ◽  
Yuna Niimi ◽  
Makoto Tomita ◽  
Hiroshi Terashima ◽  
Tadao Hasegawa ◽  

AbstractThere is a great demand for novel disinfection technologies to inactivate various pathogenic viruses and bacteria. In this situation, ultraviolet (UVC) disinfection technologies seem to be promising because biocontaminated air and surfaces are the major media for disease transmission. However, UVC is strongly absorbed by human cells and protein components; therefore, there are concerns about damaging plasma components and causing dermatitis and skin cancer. To avoid these concerns, in this study, we demonstrate that the efficient inactivation of bacteria is achieved by visible pulsed light irradiation. The principle of inactivation is based on transient photothermal heating. First, we provide experimental confirmation that extremely high temperatures above 1000 K can be achieved by pulsed laser irradiation. Evidence of this high temperature is directly confirmed by melting gold nanoparticles (GNPs). Inorganic GNPs are used because of their well-established thermophysical properties. Second, we show inactivation behaviour by pulsed laser irradiation. This inactivation behaviour cannot be explained by a simple optical absorption effect. We experimentally and theoretically clarify this inactivation mechanism based on both optical absorption and scattering effects. We find that scattering and absorption play an important role in inactivation because the input irradiation is inherently scattered by the bacteria; therefore, the dose that bacteria feel is reduced. This scattering effect can be clearly shown by a technique that combines stained Escherichia coli and site selective irradiation obtained by a wavelength tunable pulsed laser. By measuring Live/Dead fluorescence microscopy images, we show that the inactivation attained by the transient photothermal heating is possible to instantaneously and selectively kill microorganisms such as Escherichia coli bacteria. Thus, this method is promising for the site selective inactivation of various pathogenic viruses and bacteria in a safe and simple manner.

Yan-Song Zhang ◽  
Zhi-Qun Wang ◽  
Wei-Cheng Chuang ◽  
Shun-An Jiang ◽  
Ting-Shan Mo ◽  

Sign in / Sign up

Export Citation Format

Share Document