arXiv subjects

Peng Yuan

Publications and source records attributed to Peng Yuan.

40 records · Page 3Linked to original sources

arXiv2015

Black phosphorus as saturable absorber for the Q-switched Er:ZBLAN fiber laser at 2.8 μm

Black phosphorus, a newly emerged two-dimensional material, has attracted wide attention as novel photonic material. Here, multi-layer black phosphorus is successfully fabricated by liquid phase exfoliation method. By employing black phosphorus as saturable absorber, we demonstrate a passively Q-switched Er-doped ZBLAN fiber laser at the wavelength of 2.8 μm. The modulation depth and saturation fluence of the black phosphorus saturable absorber are measured to be 15% and 9 μJ/cm2, respectively. The Q-switched fiber laser delivers a maximum average power of 485 mW with corresponding pulse energy of 7.7 μJ and pulse width of 1.18 μs at repetition rate of 63 kHz. To the best of our knowledge, this is the first time to demonstrate that black phosphorus can realize Q-switching of 2.8-μm fiber laser. Our research results show that black phosphorus is a promising saturable absorber for mid-infrared pulsed lasers.

physics.optics↗

arXiv2015

Scattering-initiated parametric noise in optical parametric chirped-pulse amplification

We experimentally study a new kind of parametric noise that is initiated from signal scattering and enhanced through optical parametric amplification. Such scattering noise behaves similarly to the parametric super-fluorescence in the spatial domain, yet is typically much stronger. In the time domain, it inherits the chirp of signal pulses and can be well compressed. We demonstrate that this scattering-initiated parametric noise has little influence on the amplified pulse contrast but can degrade the conversion efficiency substantially.

physics.optics↗

arXiv2015

Similariton-like Pulses in Synchronously Pumped Singly Resonant Optical Parametric Oscillators

Similariton-like pulses are found to be formed in synchronously pumped singly resonant optical parametric oscillators (OPO) by numerical simulation. The nonlinear coupled-wave equations can be reduced to inhomogeneous nonlinear Schrödinger equation. The signal pulses with parabola-like temporal intensity profile and linear chirp are presented in OPO. The similariton-like pulses in OPO have many practical and potential applications.

nlin.PS↗

arXiv2010

Discriminating between Nasal and Mouth Breathing

The recommendation to change breathing patterns from the mouth to the nose can have a significantly positive impact upon the general well being of the individual. We classify nasal and mouth breathing by using an acoustic sensor and intelligent signal processing techniques. The overall purpose is to investigate the possibility of identifying the differences in patterns between nasal and mouth breathing in order to integrate this information into a decision support system which will form the basis of a patient monitoring and motivational feedback system to recommend the change from mouth to nasal breathing. Our findings show that the breath pattern can be discriminated in certain places of the body both by visual spectrum analysis and with a Back Propagation neural network classifier. The sound file recoded from the sensor placed on the hollow in the neck shows the most promising accuracy which is as high as 90%.

cs.NE↗